Controlled environmental stratification for intercropped plant cultivation

Abstract

Upper plant(s) of a first plant type and having an upper plant canopy, and lower plant(s) of a second plant type and having a lower plant canopy, are provided. The first plant type is different from the second plant type. The lower plant canopy is disposed below the upper plant canopy with the upper plant canopy at least partially overlapping the lower plant canopy. An upper canopy environment having an upper canopy air temperature is maintained surrounding the upper plant canopy, and a lower canopy environment having a lower canopy air temperature is maintained surrounding the lower plant canopy. The upper canopy air temperature is different from the lower canopy air temperature. The first plant type is better suited to the upper canopy environment than to the lower canopy environment, and the second plant type is better suited to the lower canopy environment than to the upper canopy environment.

Description

CONTROLLED ENVIRONMENTAL STRATIFICATION FOR INTERCROPPED PLANTCULTIVATIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Canadian Patent Application No. 3,215,200 filed on October 3, 2023.BACKGROUND

[0002] Indoor horticultural applications often require the use of artificial light as a substitute for, or a supplement to, natural lighting in order to promote the growth of the plants being cultivated. Artificial lighting used to promote the growth of plants is referred to herein as “agricultural lighting”, and the systems used to provide such light are referred to as “agricultural lighting systems”. Such artificial light may include the ultraviolet (UV) portion of the spectrum.

[0003] Agricultural lighting systems can generate considerable heat, which can be damaging, and potentially fatal, to the plants being cultivated. In addition to the heat generated by the agricultural lighting system there is also humidity produced from plant respiration. Attempts to manage this combination of heat and humidity have often focused on first controlling the temperature and airflow in the facility in which the plants are being grown, and then on controlling the temperature and airflow in the particular room(s) in which the plants are being grown. This approach can be wasteful and energy inefficient by circulating and cooling more air than may be necessary, and may yet fail to effectively condition the environment surrounding the plants.

[0004] An additional challenge in indoor agricultural applications arises where different types of plants are to be cultivated - these plants may have different requirements or preferences in terms of heat and humidity, requiring the use of different spaces for different plant types, which inhibits the efficiency of the cultivation operation.BRIEF SUMMARY

[0005] In one aspect, a method for air distribution and heat extraction for a plant canopy comprises applying positive air pressure on a ventral side of the plant canopy while applying negative air pressure on a dorsal side of the plant canopy so that the negative air pressure draws air supplied by the positive air pressure on the ventral side of the plant canopy across the plantcanopy past the dorsal side of the plant canopy to withdraw heat from the plant canopy. The heat may be, for example, from an agricultural lighting system. This method can be leveraged to enable intercropping of plants of different types, where the canopies of one plant type overlap the canopies of another plant type, with each canopy being surrounded by its own environment tailored to that plant type.

[0006] A method for plant cultivation, the method comprises providing at least one upper plant of a first plant type and having an upper plant canopy, and providing at least one lower plant of a second plant type and having a lower plant canopy. The first plant is different from the second plant type. The lower plant canopy is disposed below the upper plant canopy with the upper plant canopy at least partially overlapping the lower plant canopy. According to the method, an upper canopy environment is maintained surrounding the upper plant canopy, with the upper canopy environment having an upper canopy air temperature, and a lower canopy environment is maintained surrounding the lower plant canopy, with the lower canopy environment having a lower canopy air temperature. The upper canopy air temperature is different from the lower canopy air temperature. The first plant type is better suited to the upper canopy environment than to the lower canopy environment, and the second plant type is better suited to the lower canopy environment than to the upper canopy environment.

[0007] The upper canopy environment may have a different humidity than the lower canopy environment.

[0008] There may be a temperature gradient between the upper canopy environment and the lower canopy environment.

[0009] The method may further comprise shielding the lower canopy environment against air spillover from the upper canopy environment.

[0010] In some embodiments, the method may further comprise providing at least one intermediate plant of the second plant type and having an intermediate plant canopy. The intermediate plant canopy may be disposed above the lower plant canopy and below the upper plant canopy with the upper plant canopy at least partially overlapping the intermediate plant canopy. The lower canopy environment may be maintained surrounding the intermediate plant canopy.

[0011] In some embodiments, the method may further comprise providing at least one intermediate plant of a third plant type and having an intermediate plant canopy, where the third plant type is different from both the first plant type and the second plant type. In suchembodiments, the intermediate plant canopy may be disposed above the lower plant canopy and below the upper plant canopy with the upper plant canopy at least partially overlapping the intermediate plant canopy. An intermediate canopy environment is maintained surrounding the intermediate plant canopy, with the intermediate canopy environment having an intermediate canopy air temperature that is different from both the upper canopy air temperature and the lower canopy air temperature.

[0012] In some embodiments, the lower canopy environment is cooler than the upper canopy environment and a root zone of the upper plant(s) is disposed within the lower canopy environment.

[0013] A controlled environmental stratification system for intercropped plant cultivation comprises at least one air supply plenum configured to supply positive air pressure to a plurality of spaced apart upper canopy airflow outlets and to a plurality of spaced apart lower canopy airflow outlets. The upper canopy airflow outlets are arranged at an upper height and the lower canopy airflow outlets are arranged at a lower height that is below the upper height. At least one upper air return duct is positioned above the upper height and configured to apply negative air pressure above the upper canopy airflow outlets.

[0014] In some embodiments, the controlled environmental stratification system comprises at least one upper canopy air supply plenum configured to supply a first positive air pressure to the upper canopy airflow outlets and at least one lower canopy air supply plenum configured to supply a second positive air pressure to the lower canopy airflow outlets. In such embodiments, the lower air supply plenum(s) may be in fluid communication with a plurality of spaced -apart plant carrier plenums in which the lower canopy airflow outlets are formed and the plant carrier plenums may extend substantially perpendicular to and are disposed atop the upper air supply plenum. The plant carrier plenums may include channels formed therein and adapted to receive plant containers, with the lower canopy airflow outlets extending alongside the channels.

[0015] The upper canopy air supply plenum(s) may extend substantially in parallel with the lower canopy air supply plenum(s).

[0016] In some embodiments, the controlled environmental stratification system comprises at least one common air supply plenum supplying the positive air pressure to both the upper canopy airflow outlets and lower canopy airflow outlets. In such embodiments, the common air supply plenum(s) may be in fluid communication with a plurality of spaced-apart plant carrier plenums in which the lower canopy airflow outlets are formed and the plant carrier plenumsmay extend substantially perpendicular to and are disposed atop the common air supply plenum(s). The plant carrier plenums may include channels formed therein and adapted to receive plant containers, with the lower canopy airflow outlets extending alongside the channels.

[0017] In some embodiments, the at least one upper air return duct(s) may be configured to withdraw air supplied by both the upper canopy airflow outlets and the lower canopy airflow outlets.

[0018] In some embodiments, the controlled environmental stratification system may further comprise at least one lower air return duct positioned between the lower height and the upper height and configured to apply negative air pressure above the lower canopy airflow outlets and below the upper canopy airflow outlets.

[0019] In some embodiments, the controlled environmental stratification system comprises a modular recirculating air distribution and heat extraction system comprising an HVAC system. The HVAC system may be an integrated HVAC system comprises an air circulation mechanism, at least one cooling coil adapted to remove moisture, at least one first reheating coil downstream of the at least one cooling coil, and at least one second reheating coil downstream of the at least one cooling coil, all positioned within a cabinet of the modular recirculating air distribution and heat extraction system. The air circulation mechanism is adapted to pull untreated air through the one upper air return duct(s) (and through the lower air return duct(s) where present) to apply the negative air pressure above the upper canopy airflow outlets. The air circulation mechanism is further adapted to push treated air through the upper canopy air supply plenum(s) to supply the first positive air pressure to the upper canopy airflow and through the lower canopy air supply plenum(s) to supply the second positive air pressure to the lower canopy airflow outlets.

[0020] In some particular embodiments, the first reheating coil(s) and the second reheating coil(s) are arranged in parallel. The first reheating coil(s) will receive cooled air from the cooling coil(s) and reheat the cooled air to a first temperature to become first reheated air and supply the first reheated air to either the upper canopy air supply plenum(s) or the lower canopy air supply plenum(s). The second reheating coil(s) will receive the cooled air from the cooling coil(s) and reheat the cooled air to a second temperature to become second reheated air and supply the second reheated air to the other of the upper canopy air supply plenum (s) and thelower canopy air supply plenum(s). The first temperature and the second temperature are different from one another.

[0021] In certain preferred embodiments, the cooling coil(s), the first reheating coil(s) and the second reheating coil(s) have respective modulating valves to regulate fluid flow therethrough, and a control system independently regulates fluid flow through each of the cooling coil(s), the first reheating coil(s) and the second reheating coil(s). The control system may comprise a proportional-integral-derivative (PID) controller.

[0022] The controlled environmental stratification system may further comprise a lower canopy agricultural lighting system positioned between the lower height and the upper height, or an upper canopy agricultural lighting system positioned above the upper height, or both a lower canopy agricultural lighting system positioned between the lower height and the upper height and an upper canopy agricultural lighting system positioned above the upper height.

[0023] In some embodiments, the controlled environmental stratification system comprises at least one shield configured to inhibit air spillover from the upper canopy airflow outlets toward the lower canopy airflow outlets. The shield(s) may be an air curtain or a deflector.

[0024] In preferred embodiments, the upper canopy airflow outlets are adjustable nozzles whereby airflow through the upper canopy airflow outlets is adjustable.

[0025] In some embodiments, the upper height is adjustable.

[0026] A plant cultivation system may comprise a plurality of controlled environmental stratification systems as described above, arranged in vertical tiers.

[0027] In some embodiments, the controlled environmental stratification system uses a plurality of canopy air supply regulators.

[0028] One implementation of a canopy air supply regulator comprises a hollow tube having an inlet end and an outlet end, and an air concentrator scoop carried by the hollow tube. The inlet end of the tube and the air concentrator scoop cooperate to define contours of an inlet aperture of the regulator, and the air concentrator scoop is selectively displaceable relative to the hollow tube to adjust the contours of the inlet aperture.

[0029] In some preferred embodiments, the inlet end is truncated obliquely relative to an axial direction of the tube.

[0030] In some embodiments, the air concentrator scoop is selectively axially extendible and retractable along the hollow tube to vary the extent by which the air concentrator scoopprotrudes beyond the inlet end and thereby adjust the contours of the inlet aperture. In some particular embodiments, the air concentrator scoop is selectively axially rotatable relative to the hollow tube to further adjust the contours of the inlet aperture. The air concentrator scoop may be nested within the hollow tube.

[0031] In some embodiments, the air concentrator scoop comprises a resilient sheet biased into a planar configuration. The resilient sheet is rolled into a scoop-ended inner tube that is received within the hollow tube wherein the bias into the planar configuration retains the scoop - ended inner tube in slidable frictional engagement with an inner surface of the hollow tube.BRIEF DESCRIPTION OF THE DRAWINGS

[0032] These and other features will be described with reference to the following illustrative drawings, wherein:

[0033] FIG. 1 illustrates, in schematic form, a method for air distribution and heat and humidity extraction for a plant canopy;

[0034] FIG. 2 illustrates an air distribution and heat extraction system in accordance with a first embodiment;

[0035] FIG. 3 shows an illustrative air distribution and heat extraction system similar to that shown in FIG. 2 but in which the support is a tiered support comprising a plurality of individual tiers;

[0036] FIG. 4 shows two illustrative air return ducts coupled to an illustrative agricultural lighting system;

[0037] FIG. 5 shows an illustrative air return duct arranged in opposed relation to, and in registration with, a corresponding air supply duct;

[0038] FIG. 6 shows how two sets of ducts can be connected to form a complete air return duct;

[0039] FIG. 7 is a top perspective view of a multipurpose cultivation carrier that can be used in accordance with aspects of the present disclosure;

[0040] FIGS. 8 A and 8B show how plant containers can be slidingly received in the multipurpose cultivation carrier of FIG. 7;

[0041] FIGS. 9 A and 9B show how manifold plates can be slidingly received in the multipurpose cultivation carrier to form an air manifold;

[0042] FIGS. 10A, 10B and 11 are partial cut-away views illustrating an air distribution and heat extraction system in accordance with a second embodiment;

[0043] FIG. 12 is a partially exploded, partial cut-away top front perspective view illustrating an air distribution and heat extraction system in accordance with a third embodiment;

[0044] FIG. 12A is a detail view of a portion of FIG. 12;

[0045] FIG. 13 is an assembled partial cut-away top front perspective view of the air distribution and heat extraction system of FIG. 12;

[0046] FIG. 14 is an assembled front perspective view of the air distribution and heat extraction system of FIG. 12 with a light containment curtain thereof partially open;

[0047] FIG. 15 is an assembled front perspective view of the air distribution and heat extraction system of FIG. 12 with the light containment curtain thereof closed;

[0048] FIG. 16 is a partially exploded, partial cut-away top rear perspective view of the air distribution and heat extraction system of FIG. 12;

[0049] FIG. 17 is an assembled partial cut-away top rear perspective view of the air distribution and heat extraction system of FIG. 12;

[0050] FIG. 18 is a partial cut-away view of a portion of an air distribution and heat extraction system in accordance with an alternate embodiment including a heat exchanger;

[0051] FIG. 19 schematically illustrates a first embodiment of a method for controlled environmental stratification for intercropped plant cultivation wherein plants of a first plant type have an upper plant canopy disposed in an upper canopy environment and plants of a second plant type have a lower plant canopy disposed in a lower canopy environment, with the plant canopies at least partially overlapping;

[0052] FIG. 19A schematically illustrates a second embodiment of a method for plant cultivation, similar to that shown in Figure 19 and further including plants of a third plant type having an intermediate plant canopy disposed in an intermediate canopy environment disposed between the upper canopy environment and the lower canopy environment;

[0053] FIG. 20 shows an illustrative canopy air supply regulator;

[0054] FIG. 21 A shows a resilient sheet for forming an air concentrator scoop of the canopy air supply regulator of Figure 20;

[0055] FIG. 21B shows the resilient sheet of Figure 21A rolled into a scoop-ended inner tube;

[0056] FIG. 22 shows the scoop-ended inner tube of Figure 2 IB slid into a hollow tube to form the canopy air supply regulator of Figure 20;

[0057] FIG. 23 A shows how the canopy air supply regulator of Figure 20 can be used in conjunction with a canopy airflow nozzle and an extension tube;

[0058] FIG. 23B shows how the canopy air supply regulator of Figure 20 can be used in conjunction with a canopy airflow nozzle absent an extension tube;

[0059] FIG. 24 shows how the canopy air supply regulator of Figure 20 can be used in conjunction with an air curtain nozzle;

[0060] FIGS. 25 A and 25B show how the canopy air supply regulator of Figure 20 can be used in conjunction with a first illustrative plant carrier plenum;

[0061] FIG. 26 shows a first illustrative embodiment of a controlled environmental stratification system for intercropped plant cultivation configured to implement the method shown in Figure 19;

[0062] FIG. 26A shows a plurality of instances of the controlled environmental stratification system of Figure 26 arranged in vertical tiers;

[0063] FIG. 27 is a side cross-sectional view showing airflows through the controlled environmental stratification system of Figure 26;

[0064] FIG. 27A is a side cross-sectional view showing airflows through a modified version of the controlled environmental stratification system of Figure 26;

[0065] FIG. 27B is a side cross-sectional view of the modified version of the controlled environmental stratification system shown in Figure 27A, showing an upper canopy environment therein that is distinct from a lower canopy environment therein;

[0066] FIG. 28 is an end cross-sectional view showing airflows through the controlled environmental stratification system of Figure 26;

[0067] FIGS. 29A and 29B show how the canopy air supply regulator of Figure 20 can be used in conjunction with a second illustrative plant carrier plenum;

[0068] FIG. 30 shows a second illustrative embodiment of a controlled environmental stratification system for intercropped plant cultivation configured to implement the method shown in Figure 19;

[0069] FIG. 30A shows a plurality of instances of the controlled environmental stratification system of Figure 30 arranged in vertical tiers;

[0070] FIG. 31 is a cross-sectional view of an illustrative embodiment of a lower canopy air supply plenum of the controlled environmental stratification system of Figure 30, coupled to a plant carrier plenum thereof;

[0071] FIG. 32 is a cut-away view of a modular recirculating HVAC cabinet for the controlled environmental stratification system of Figure 30;

[0072] FIGS. 33A through 33C are side cross-sectional views showing airflows through the controlled environmental stratification system of Figure 30;

[0073] FIGS. 34A through 34C are end cross-sectional views showing airflows through the controlled environmental stratification system of Figure 30; and

[0074] FIGS. 35A and 35B are, respectively, side cross-sectional and end cross-sectional views of a containerized embodiment of a vertically tiered controlled environmental stratification system for plant cultivation.DETAILED DESCRIPTION

[0075] The present disclosure describes a “plant forward” solution which focuses primarily on removing undesired heat and humidity from the plants, and particularly from the vulnerable plant canopy. Air is made to flow directly across the plant canopy from a ventral side thereof to a dorsal side thereof.

[0076] Reference is now made to Figure 1, which illustrates, in schematic form, a method 100 for air distribution and heat extraction for a plant canopy, denoted generally by reference 102. The method comprises applying positive air pressure 104 on a ventral side 106 of the plant canopy 102 and applying negative air pressure 108 on a dorsal side 110 of the plant canopy 102. By this arrangement, the negative air pressure 108 draws air supplied by the positive air pressure 104 on the ventral side 106 of the plant canopy 102 across the plant canopy 102 past the dorsal side 110 of the plant canopy 102 to withdraw heat from the plant canopy 102. The heat may be, for example, primarily from an agricultural lighting system 112. For example, the MetaRail™ or HyperRail™ agricultural lighting system offered by AgricUltra Advancements Inc., having an address at 3723 Mountainview Road, Beamsville, ON, L3J 2C9 Canada may be used. The MetaRail agricultural lighting system provides UVA and UVB light, and the HyperRail agricultural lighting system provides UVA, UVB and visible light.In the illustrated embodiment, the positive air pressure 104 results from forced air 118, for example from a bulk treated air source 114 of an HVAC system 116 (“HVAC” refers to“heating, ventilation and air conditioning”), and the negative air pressure 108 results from suction 120 into a bulk return inlet 122 of the HVAC system 116. Preferably, the forced air 118 is actively cooled, for example by the HVAC system 116 before reaching the ventral side 106 of the plant canopy 102. In one embodiment, described further below, heat transfer between an uncooled portion of the forced air and a cooled portion of the forced air that is downstream of the uncooled portion of the forced air simultaneously preheats the cooled portion of the forced air before reheating thereof and pre-cools the uncooled portion of the forced air before cooling thereof. Also preferably, the forced air is cleaned, for example by way of filter and / or electrostatic treatment and / or UV treatment, before reaching the ventral side 106 of the plant canopy 102. In other embodiments, where the ambient temperature is low enough, the forced air may be ambient air.

[0077] Reference is now made to Figure 2, in which an illustrative air distribution and heat extraction system 200 for plant cultivation is shown. This is merely one illustrative embodiment, and is not intended to be limiting.

[0078] The air distribution and heat extraction system 200 comprises a support 224 which includes a longitudinally extending platform 226, and further comprises a longitudinally extending agricultural lighting system 212, two air supply ducts 232, two air return ducts 234, and a plurality of plants 228 carried by the platform 226. Each of the plants 228 has a plurality of leaves 230 forming a plant canopy 202. While the illustrated embodiment shows a plurality of plants 228 carried by the platform 226, in other embodiments there may be only a single plant carried by the support, with the leaves of the single plant forming the plant canopy. The agricultural lighting system 212 is disposed on the dorsal side of the plant canopy 202 and is arranged substantially parallel to and in registration with the platform 226 so as to deliver agricultural light to the dorsal side 210 of the plant canopy 202.

[0079] In the illustrated embodiment, the air supply ducts 232 are disposed on either side of the platform 226 along the long edges thereof, and the air return ducts 234 are similarly disposed on either side of the agricultural lighting system 212 along the long edges thereof. Thus, in the illustrated embodiment the air return ducts 234 are carried by the agricultural lighting system 212. In other embodiments, the air return duct(s) may be separate from and unsupported by the agricultural lighting system. While the illustrated embodiment has two air supply ducts 232 and two air return ducts 234, other embodiments may have a single air supplyduct and / or more than two air supply ducts and / or only a single air return duct and / or more than two air return ducts.

[0080] The air supply ducts 232 are positioned and configured to apply positive air pressure 204 on the ventral side 206 of the plant canopy 202 and the air return ducts 234 are positioned and configured to apply negative air pressure 208 on the dorsal side of the plant canopy 202. By this arrangement, when the positive air pressure 204 and the negative air pressure 208 are applied, the negative air pressure 208 draws air supplied by the positive air pressure 204 on the ventral side 206 of the plant canopy 202 across the plant canopy 202 past the dorsal side 210 of the plant canopy 202 to withdraw heat from the plant canopy 202. There may also be considerable humidity around the plant canopy 202, substantially from plant respiration; as the negative air pressure 208 draws air supplied by the positive air pressure 204 on the ventral side 206 of the plant canopy 202 across the plant canopy 202 past the dorsal side 210 of the plant canopy 202 it will also withdraw humidity from the plant canopy 202

[0081] As can be seen in Figure 2, the air supply ducts 232 are coupled in fluid communication with an HVAC system 216 and configured to receive treated forced air 218 from the HVAC system 216; the forced air 218 from the HVAC system 216 may be actively cooled and / or cleaned. Similarly, the air return ducts 234 are coupled in fluid communication with the HVAC system 216 and configured to deliver the air drawn from the plant canopy 202 to a bulk return inlet 222 of the HVAC system 216. In other embodiments, the air return ducts 234 may vent to ambient.

[0082] In the illustrated embodiment, the platform 226 is shown spaced from the floor of a building in which the air distribution and heat extraction system 200 is disposed; in other embodiments the building floor may itself serve as the support, and the air supply duct(s) may be embedded in the building floor.

[0083] Figure 3 shows an illustrative air distribution and heat extraction system 300 which is similar to the air distribution and heat extraction system 200 shown in Figure 2 but in which the support 324 is a tiered support 324 comprising a plurality of individual tiers 340. A plurality of plants 328 are arranged on the tiers 340 of the tiered support 324 whereby there are a plurality of tiered plant canopies 302, and there are a plurality of air return ducts 334 disposed on the dorsal sides of respective ones of the plant canopies 302. In the illustrated embodiment shown in Figure 3, a plurality of air supply ducts 332 are disposed on ventral sides of respective onesof the plant canopies 302; in other embodiments a single air supply duct may be disposed on the ventral side of the lowermost plant canopy.

[0084] Figure 4 shows two illustrative air return ducts 234 coupled to an illustrative agricultural lighting system 212. Although Figure 4 shows the air return ducts 234 on both sides of the agricultural lighting system 212, on other embodiments there may be only a single air return duct on one side of the agricultural lighting system 212. Similar arrangements may be used with respect to the air supply ducts 232 and the platform 226. In the illustrated embodiment, coupling is by way of a channel -and-groove interference fit although any suitable coupling mechanism may be used.

[0085] Figure 5 shows an illustrative air return duct 234 arranged in opposed relation to, and in registration with, a corresponding air supply duct 232. In the illustrated embodiment, the air return ducts 234 and air supply ducts 232 take the form of open-ended, hollow rectangular duct 502, 504 having a series of airflow apertures 436. The ducts 502, 504 may be of various sizes to accommodate various airflow requirements and / or HVAC systems. For example, ducts 502, 504 may be provided which are sized to remove 700 cubic feet per minute (CFM), 1000 CFM or 1200 CFM, depending on the application.

[0086] Figure 6 shows how two sets of ducts 502 can be connected end-to-end in fluid communication using an O-ring style sealable connector 602 having at least one airflow passage 604 therethrough and a sealing endcap 606 at a downstream terminal end, so as to form a complete air supply duct 232. A similar approach can be used to connect ducts 504 to form a complete air return duct 234.

[0087] Reference is now made to Figures 7 to 9B, which show a multipurpose cultivation carrier, indicated generally by reference 700, which can be used in accordance with aspects of the present disclosure. The multipurpose cultivation carrier 700 may be configured for use as a plant carrier, or as an air plenum for an air manifold.

[0088] The multipurpose cultivation carrier 700 has a longitudinally extending channel 702 defined therein and is adapted to removably slidably receive instances of a plant container 800 (Figure 8 A) or a manifold plate 900 (Figure 9A). The multipurpose cultivation carrier 700 is of generally C-shaped cross section. The illustrated multipurpose cultivation carrier 700 comprises two opposed, substantially parallel generally planar sidewalls 704 spaced from one another by a generally planar base wall 706. The inner faces 708 of the sidewalls 704 have opposed longitudinally-extending inward projections 710 which form longitudinally extendingguide grooves 712 that are dimensioned to receive the peripheral rim 802 (Figure 8 A) of the plant container 800 so as to maintain the plant container 800 within the longitudinally extending channel 702. Thus, the plant container 800 can be slid into the longitudinally extending channel 702 as shown in Figure 8A. Typically, a series of the plant containers 800 are received in the channel 702, as shown in Figure 8B.

[0089] The longitudinally extending guide grooves 712 are further dimensioned to receive the outer side edges 902 of a manifold plate 900. Such a manifold plate 900 is shown in Figure 9A and, in the illustrated embodiment, comprises a main plate 904 that includes a guide projection 906 on its underside to help center it in the longitudinally extending channel 702. Other arrangements for securing a manifold plate to the multipurpose cultivation carrier 700 may also be used. The ends of each manifold plate 900 may comprise a tongue and groove snap (not shown) with the male end sliding over the female end forming a partial seal and locking the manifold plates 900 together end-to-end. The manifold plate 900 further comprises two upwardly depending nipples 908 each adapted to releasably sealingly receive a diffuser / reducer 910. The air flow can be adjusted by selectively installing a diffuser / reducer 910 having the desired flow rate. A series of the manifold plates 900 can be slid into the channel 702 in sealed end-to-end relation as shown in Figure 9A, and then a sealing member (not shown) can be installed at one end of the multipurpose cultivation carrier 700 so that the multipurpose cultivation carrier 700 serves as an air plenum and cooperates with the manifold plates 900, nipples 908 and diffuser / reducers 910 to form an air manifold 1032, as shown in Figure 9B. The multipurpose cultivation carrier 700 may be used, for example, in a modular recirculating embodiment of an air distribution and heat extraction system according to an aspect of the present disclosure.

[0090] Reference is now made to Figures 10A and 10B, which show one illustrative embodiment of a modular recirculating air distribution and heat extraction system, indicated generally by reference 1000.

[0091] The modular air distribution and heat extraction system 1000 comprises a support 1024 which includes a cabinet 1004, a longitudinally extending platform 1026 coupled to the cabinet 1004, and a longitudinally extending agricultural lighting system 1012 coupled to the cabinet 1004. The agricultural lighting system 1012 may be of any suitable type; in the illustrated embodiment the agricultural lighting system 1012 comprises a plurality of spaced -apart lighting bars 1014 suspended from fixture arms 1010 extending from the cabinet 1004 substantiallyparallel to the platform 1026, which also extends from the cabinet 1004. The lighting bars 1014 may be, for example, MetaRail™ or HyperRail™ lighting bars. An air return duct 1034 also extends substantially parallel to the platform 1026, and may be supported directly or indirectly by the fixture arms 1010. For example, the air return duct 1034 may rest atop the lighting bars 1014. Two air supply ducts 1032, each formed from an assembly of the multipurpose cultivation carrier 700, manifold plates 900 and diffuser / reducers 910 as shown in Figure 9B, are disposed on either side of the platform 1026 along the long edges thereof. While the illustrated embodiment has two air supply ducts 1032 and a single air return duct 1034, other embodiments may have a single air supply duct and / or more than two air supply ducts and / or more than one air return ducts.

[0092] A recirculation duct 1016 passes through the cabinet 1004 of the modular air distribution and heat extraction system 1000 and connects the air return duct 1034 in fluid communication with the air supply ducts 1032. A fan 1018 is disposed in cabinet 1004 and configured to draw air from the air return duct 1034 and supply that air to the air supply ducts 1032. Thus, the fan 1018 is configured to apply negative pressure to the air return duct 1034 and to apply positive pressure to the air supply ducts 1032. The fan 1018 is preferably a variable speed fan to support different flow rates depending on the configuration, for example for different lengths of the platform 1026. Although a fan is shown for purposes of illustration, any suitable air circulation mechanism may be used. A cooling coil 1042, reheat coil 1044 and UV sterilizing lighting 1046 are disposed in the recirculation duct 1016, interposed between the air return duct 1034 and the air supply ducts 1032. The cooling coil 1042 cools and dehumidifies air drawn from the air return duct 1034, the reheat coil 1044 can reheat the air to a desired temperature set point if too much cooling is applied, and the UV sterilizing lighting 1046 sterilizes any condensate that may accumulate on the cooling coil 1042. Certain features are not shown for simplicity of illustration but are within the capability of one skilled in the art, now informed by the present disclosure. For example, thermostatic control, one or more valves (e.g. three-way valves to control flow through the coils for 1042, 1044 for load control), and drainage for dehumidification may be provided. The cooling coil 1042 and the reheat coil 1044 may be circulating fluid coils coupled to components such as chillers, circulation pumps and compression fluid coolers, which may be integrated into the cabinet 1004 of the modular recirculating air distribution and heat extraction system 1000 or may be external thereto. Thus, the modular recirculating air distribution and heat extraction system 1000 includes an integrated HVAC system comprising the recirculation duct 1016, fan 1018, cooling coil 1042, reheat coil1044 and optional UV sterilizing lighting 1046, all positioned within the cabinet 1004 of the modular recirculating air distribution and heat extraction system 1000. The HVAC system is, aside from any external connections for electrical power and circulating air conditioning fluids to external components, substantially self-contained.

[0093] In one embodiment, a third multipurpose cultivation carrier 700 is disposed between the two air supply ducts 1032 on the platform 1026, and a plurality of plant containers 800 containing plants 1028 can be slidably received therein so that the plants 1028 are carried by the platform 1026, as shown in Figure 10B. Each of the plants 1028 has a plurality of leaves 1030 forming a plant canopy 1002. The agricultural lighting system 1012 is disposed on the dorsal side of the plant canopy 1002 and is arranged to deliver agricultural light to the dorsal side of the plant canopy 1002.

[0094] The air supply ducts 1032 are positioned and configured to apply positive air pressure on the ventral side of the plant canopy 1002 and the air return ducts 1034 are positioned and configured to apply negative air pressure on the dorsal side of the plant canopy 1002. By this arrangement, when the positive air pressure and the negative air pressure are applied, the negative air pressure draws air supplied by the positive air pressure on the ventral side of the plant canopy 1002 across the plant canopy 1002 past the dorsal side of the plant canopy 1002 to withdraw heat and moisture from the plant canopy 1002. The air is then recirculated through the recirculation duct 1016, where it is conditioned by the cooling coil 1042, reheat coil 1044 and optional UV sterilizing lighting 1046, and then returned to the air supply ducts 1032.

[0095] Figure 11 shows an arrangement of the modular recirculating air distribution and heat extraction system 1000 in which, instead of a third multipurpose cultivation carrier 700, a plurality of individual plant containers 1100 are disposed between the two air supply ducts 1032, directly on the platform 1026. Thus, the modular recirculating air distribution and heat extraction system 1000 is compatible with a wide range of plant containers.

[0096] While the illustrated embodiments show a plurality of plants 1028 carried by the platform 1026, in other embodiments there may be only a single plant carried by the support, with the leaves of the single plant forming the plant canopy.

[0097] Multiple instances of the modular recirculating air distribution and heat extraction system 1000 can be arranged in tiers, analogously to the arrangement shown in Figure 3.

[0098] As can be seen in Figures 10A to 11, the multipurpose cultivation carriers 700, including those that form the air supply ducts 1032 and those that carry the plants 1028, extend substantially parallel to the direction of airflow through the air return duct 1034.

[0099] Reference is now made to Figures 12 to 17, which show another illustrative embodiment of a modular recirculating air distribution and heat extraction system, indicated generally by reference 1200. The modular recirculating air distribution and heat extraction system 1200 shown in Figures 12 to 17 is conceptually similar to the modular air distribution and heat extraction system 1000 shown in Figures 10A to 11, and may make use of the same multipurpose cultivation carriers 700, manifold plates 900 and diffuser / reducers 910 shown in Figures 7 to 9B, or similar cultivation carriers, manifold plates and diffuser / reducers. Thus, in general, like reference numerals denote corresponding features, except with the prefix “12” instead of “10”. The modular recirculating air distribution and heat extraction system 1200 shown in Figures 12 to 17 differs from the modular air distribution and heat extraction system 1000 shown in Figures 10A to 11 in that the modular recirculating air distribution and heat extraction system 1200 shown in Figures 12 to 17 has the multipurpose cultivation carriers 700 and the air supply ducts 1232 extending substantially transverse to the direction of airflow through the air return duct 1034.

[0100] The modular air distribution and heat extraction system 1200 comprises a support 1224. In this embodiment, the support 1224 comprises a cabinet 1204 housing various components described further below, a longitudinally extending platform 1226 coupled to the cabinet 1204, and a longitudinally extending roof 1210 opposite the and substantially parallel to the platform 1226 and also coupled to the cabinet 1204. The roof 1210 is optional; in alternate embodiments the roof may be omitted and the air return duct(s) 1034 may function as a roof as well. A longitudinally extending agricultural lighting system 1212, which may be of any suitable type, is also provided. In the illustrated embodiment the agricultural lighting system 1212 comprises a plurality of spaced-apart lighting bars 1214, such as for example MetaRail™ or HyperRail™ lighting bars, suspended from the roof 1210.

[0101] A hollow air supply plenum 1250 is in fluid communication with the interior of the cabinet 1204 at one end of the air supply plenum 1250; the air supply plenum 1250 is closed at the other end. The air supply plenum 1250 extends from the cabinet 1204 substantially perpendicular to and substantially coterminous with the roof 1210 and platform 1226, where it meets an end plate 1248 opposite the cabinet 1204 and is also joined to the platform 1226 andthe roof 1210. The air supply plenum has a series of spaced apart supply plenum outlet apertures 1252 which feed air to a corresponding series of air supply ducts 1232. The air supply ducts 1232 may be formed using multipurpose cultivation carriers 700 and manifold plates 900 as described above and shown in Figures 9A and 9B, with a sealing member or end plate 1254 at the distal end and a hollow duct coupler 1256 at the proximal end to connect each of the air supply ducts 1232 in fluid communication with the air supply plenum 1250. The air supply ducts 1232 rest on the platform 1226. An air return duct 1234 having a plurality of inlet apertures 1236 also extends substantially parallel to the platform 1226, and may be supported directly or indirectly by the roof 1210 (where a roof is present) or by other structural elements. Thus, in the illustrated embodiment, the air return duct 1234 is separate from and unsupported by the agricultural lighting system 1212. While the illustrated embodiment shows a single air return duct 1234, other embodiments may have more than one air return duct.

[0102] Because the air supply plenum outlet apertures 1252 are spaced apart, the air supply ducts 1232 are also spaced apart along the length of the platform 1226. Multipurpose cultivation carriers 700, each having plurality of plant containers 800 containing plants 1228 slidably or otherwise received therein, can fit between adjacent ones of the air supply ducts 1232 on the platform 1226 so that the plants 1228 are carried by the platform 1226. Each of the plants 1228 has a plurality of leaves 1230 forming a plant canopy 1202. The agricultural lighting system 1212 is disposed on the dorsal side of the plant canopy 1202 and is arranged to deliver agricultural light to the dorsal side of the plant canopy 1202. The multipurpose cultivation carriers 700 used to form the air supply ducts 1232 may be of the same size as the multipurpose cultivation carriers 700 used to house the containers 800 and plants 1228, or may be of a different size. For example, the multipurpose cultivation carriers 700 used to form the air supply ducts 1232 may be smaller than the multipurpose cultivation carriers 700 used to house the containers 800 and plants 1228, as shown in Figure 12A, to provide relatively more space for the containers 800 and plants 1228. Also, by providing relatively taller air supply ducts and relatively shorter cultivation carriers for plants in a juvenile (and hence more fragile) state of development, the juvenile plants can be placed below the airflow so that little or no air blows onto the juvenile plants. This reduces the need for transplanting / moving plants from one growing environment to another as they mature.

[0103] A main irrigation / fertigation line 1260 extends along the air supply plenum 1250 above the air supply plenum outlet apertures 1252, and connects in fluid communication with branch irrigation / fertigation lines 1262 having drippers 1264 to supply water alone, or water andnutrients and / or fertilizer, to the plants 1228. Irrigation generally refers to the supply of water alone, while fertigation refers to the supply of water and nutrients / fertilizer together.

[0104] The air distribution and heat extraction system 1200 is a modular recirculating air distribution and heat extraction system. The cabinet 1204 forms a recirculation chamber 1216 that connects the air return duct 1234 in fluid communication with the air supply plenum 1250 and thereby with the air supply ducts 1232. A fan 1218, preferably a variable speed fan, is disposed in the cabinet 1204 and configured to draw air from the air return duct 1234 and supply that air to the air supply ducts 1232. The fan 1218 is thus configured to apply negative pressure to the air return duct 1234 on the dorsal side of the plant canopy 1202 and to apply positive pressure to the air supply ducts 1232 on the ventral side of the plant canopy 1202. While a fan is shown for purposes of illustration, any suitable air circulation mechanism may be used. A cooling coil 1242, reheat coil 1244 and UV sterilizing lighting 1246 are disposed in the recirculation chamber 1216 formed by the cabinet 1204. Thus, the cooling coil 1242, reheat coil 1244 and UV sterilizing lighting 1246 are interposed between the air return duct 1234 and the air supply ducts 1232. The cooling coil 1242 cools and dehumidifies air drawn from the air return duct 1234, the reheat coil 1244 can reheat the air to a desired temperature set point if too much cooling is applied, and the UV sterilizing lighting 1246 sterilizes the cooling coil 1242 and any film that may form thereon from the condensate. As a result, the air supply ducts 1232 are coupled (via duct couplers 1256 and supply plenum 1250 in fluid communication with a source of actively cooled forced air (cabinet 1204). A drip tray 1266 is provided for drainage of condensate dripping from the cooling coil 1242. The cooling coil 1242 and the reheat coil 1244 may be circulating fluid coils coupled to components such as chillers, circulation pumps and compression fluid coolers, some or all of which may be integrated into the cabinet 1204 of the modular recirculating air distribution and heat extraction system 1200 or may be external thereto. Thus, the modular recirculating air distribution and heat extraction system 1200 includes an integrated HVAC system comprising the recirculation chamber 1216 formed by the cabinet 1204, fan 1218, cooling coil 1242, reheat coil 1244 and optional UV sterilizing lighting 1246, as well as optional modulating and bypass valves, all positioned within the cabinet 1204 of the modular recirculating air distribution and heat extraction system 1200. The HVAC system is, aside from any external connections for electrical power and circulating air conditioning fluids to external components, substantially self-contained.

[0105] A retractable light containment curtain 1274 wound on a spool 1276 supported by the roof 1210 can cover the open side opposite the air supply plenum 1250 to limit UV exposure topersonnel and then be retracted to access the plants 1228. Additionally, a CO2 inlet 1268 into the recirculation chamber 1216 formed by the cabinet 1204 (or into the air supply plenum 1250) may be provided to enrich the recirculating air with CO2 to enhance plant growth. As with other embodiments, certain features within the capability of one skilled in the art, now informed by the present disclosure, are not shown for simplicity of illustration but may be present in various implementations. These include thermostatic, CO2 or other sensors for environmental control, modulating valves, bypass valves or other valves (e.g. three-way valves for load control), among others.

[0106] In the illustrated embodiment shown in Figures 12 to 17, the nipples 908 on the manifold plates 900 can be fitted with different types of diffuser / reducers or nozzles depending on the location and desired airflow and distribution goals. In the illustrated embodiment, the plants 1228 are enclosed on five sides by the end plate 1248, the air supply plenum 1250, the cabinet 1204, the roof 1210 and the platform 1226, with the side opposite the air supply plenum 1250 being open to provide access. The most distal nipples 908 (the nipples 908 furthest from the air supply plenum 1250) on each of the air supply ducts 1232 may be fitted with an air curtain nozzle 1270. The air curtain nozzles 1270 cooperate to form an air curtain on the side opposite the air supply plenum 1250, thereby effectively enclosing the plants 1228. In some embodiments, the end plate may be omitted and specialized nozzles may provide an air curtain at the end of the platform 1226 opposite the cabinet 1204. The interior nipples 908 (the nipples 908 between the most distal nipples 908 and the air supply plenum 1250) may be fitted with canopy airflow nozzles 1272 adapted to blow air through the plant canopy 1202. Because the airflow through each of the air supply ducts 1232 will vary depending on its longitudinal position along the air supply plenum 1250 (as more air is bled off), the air curtain nozzles 1270 and the canopy airflow nozzles 1272 are preferably configured to be individually adjustable so as to enable maintenance of a relatively consistent airflow for the air curtain and through the plant canopy 1202. For example, nozzles may be adjustable, or may have ports that can be selectively sealed or opened, such as by plugs. Alternatively, the nozzles may have a fixed configuration, with each configuration being designated for a specific position. Alternatively or additionally, baffle plates or other airflow control elements may be disposed within the air supply plenum 1250 and / or the air supply ducts 1232. Configuration of the nozzles will of course depend on the spacing and configuration of the end plate 1248, the air supply plenum 1250, the cabinet 1204, the roof 1210 and the platform 1226, as well as the desired airflow and distribution goals and is within the capability of one of ordinary skill in the art, now informedby the present disclosure. For example, computational fluid dynamic (CFD) modeling may be used. Additionally, as noted above the fan 1218 is preferably a variable speed fan, which may further facilitate flow control.

[0107] In operation, when the fan 1218 is active, air is forced into the air supply plenum 1250, then through the air supply plenum outlet apertures 1252 into the air supply ducts 1232, which apply positive pressure to the ventral side of the plant canopy 1202. At the same time, the fan also draws air from the air return duct 1234 past the cooling coil 1242, reheat coil 1244 and UV sterilizing lighting 1246, to thereby apply negative pressure to the air return duct 1234 on the dorsal side of the plant canopy 1002. When the positive air pressure and the negative air pressure are applied, the negative air pressure draws air supplied by the positive air pressure on the ventral side of the plant canopy 1202 across the plant canopy 1202, past the dorsal side of the plant canopy 1202, to withdraw heat (e.g. from the agricultural lighting system 1214) and humidity (substantially from plant respiration) from the plant canopy 1202. The dashed lines in Figures 12, 13 and 17 show an illustrative airflow. The use of the air curtain nozzles 1270 to form an air curtain on the side opposite the air supply plenum 1250 creates an enclosed microclimate; the light containment curtain 1274 merely limits UV light exposure from the agricultural lighting system 1212 and is not required to maintain the microclimate.Alternatively, the light containment curtain 1274 may be configured to create the enclosed microclimate and the air curtain nozzles may be omitted. A drip tray or gutter 1278 may be disposed along the platform 1276 opposite the spool 1276 for the light containment curtain 1274. A control system may be coupled to the cooling coil 1242, reheat coil 1244 and fan 1218 to control the flow rate, and the control the amount of cooling and reheating. For example, the control system may be configured to achieve a programmed target dew point for the microclimate. The control system may be coupled to thermostatic, CO2 or other sensors for environmental control, and to modulating valves, bypass valves or other valves (e.g. three-way valves for load control), among others. These will be known to one of ordinary skill in the art, now informed by the present disclosure. In addition, the control system may be coupled to the lighting bars, and may be configured to provide different lighting and environmental conditions at different times, for example to simulate night and day, or to simulate a growing season, or for other purposes, such as to provide targeted stresses to achieve a desired phytochemical profile (e.g. taste, aromatic or chemical content) or trigger a metabolic response such as a transition from vegetative into regenerative growth, or initiating vegetative growth.

[0108] Reference is now made to Figure 18, which shows an alternate embodiment of a cabinet, indicated generally by reference 1204A, for use with a modular recirculating air distribution and heat extraction system of the type shown in Figures 12 to 17. Components corresponding to those in the previously described air distribution and heat extraction system 1200 are denoted by like reference numerals, but with the suffix “A”. The cabinet 1204 A forms a recirculation chamber 1216A connecting the air return duct 1234 A in fluid communication with the air supply plenum 1250A. A fan 1218A (or other suitable air circulation mechanism) disposed in the cabinet 1204 A is configured to draw air from the air return duct 1234 A and supply that air to the air supply plenum 1250. A cooling coil 1242A and reheat coil 1244A are disposed in the recirculation chamber 1216A formed by the cabinet 1204A, with the cooling coil 1242 A positioned upstream of the reheat coil 1244 A. Although not shown in Figure 18 for ease of illustrating other features, UV sterilizing lighting may also be disposed in the cabinet 1204A.

[0109] The cabinet 1204 A shown in Figure 18 differs from the cabinet 1204 shown in Figures 12 to 17 in that an air-to-air heat exchanger 1280A is disposed in the cabinet 1204A, interposed in the airflow path 1282 A through the cabinet 1204 A. The illustrated air-to-air heat exchanger 1280A is a plate-to-plate heat exchanger but this is merely illustrative and not intended to be limiting. The air-to-air heat exchanger 1280A is configured to have a first heat exchange path 1284A upstream of the cooling coil 1242A (interposed between the air return duct 1234A and the cooling coil 1242 A) and a second heat exchange path 1286 A downstream of the cooling coil 1242A and upstream of the reheat coil 1244A (i.e. the second heat exchange path 1286A is interposed between the cooling coil 1242A and the reheat coil 1244A). The airflow path 1282A through the cabinet 1204 A carries the air from the air return duct 1234 A through the first heat exchange path 1284 A of the air-to-air heat exchanger 1280 A, then through the cooling coil 1242 A, and then through the second heat exchange path 1286 A of the air-to-air heat exchanger 1280A, and then through the reheat coil 1244A and back to the air supply plenum 1250A. Because the air from the air return duct 1234A (air drawn from the plant canopy) carries heat from the agricultural lighting system, the air-to-air heat exchanger 1280A transfers heat from the agricultural lighting system to an off-cooling-coil airstream 1288A (air emerging from the cooling coil 1242A). Thus, the air-to-air heat exchanger 1280A simultaneously pre-cools the air drawn from the plant canopy upstream of the cooling coil 1242 A and preheats the air between the cooling coil 1242 A and the reheat coil 1244 A. The pre-heated air emerging from the cooling coil 1242 A then passes to the reheat coil 1244 A, which further increases the airtemperature to the desired set point. The fully reconditioned air is then passed back to the air supply plenum 1250A for return to the ventral side of the plant canopy. In a preferred embodiment, reheat energy for the reheat coil 1244A is supplied from a chiller (external to the cabinet 1204A) via a hot gas bypass loop. Thus, heat is transferred from an uncooled portion of the forced air (air from the air return duct 1234A) to a cooled portion of the forced air (air emerging from the cooling coil 1242 A) that is downstream of the uncooled portion of the forced air. This simultaneously preheats the cooled portion of the forced air before reheating thereof (by the reheat coil 1244A) and pre-cools the uncooled portion of the forced air before cooling thereof (by the cooling coil 1242 A).

[0110] The air-to-air heat exchanger 1280 A allows both the reheat coil 1244 A and the cooling coil 1242A to be of relatively smaller physical size while maintaining full cooling capacity, and may also enable relative reduction in the size of the associated chiller system as well as a relative reduction in power consumption. As before, a control system may be coupled to the cooling coil 1242 A, reheat coil 1244 A and fan 1218A to control the flow rate, and the control the amount of cooling and reheating. A control system may be coupled to the cooling coil 1242 A, reheat coil 1244 A and fan 1218 A, to thermostatic, CO2 or other sensors for environmental control, and to modulating valves, bypass valves or other valves (e.g. three-way valves for load control), among others, to control the flow rate, and the control the amount of cooling and reheating. These will be known to one of ordinary skill in the art, now informed by the present disclosure.

[0111] Multiple instances of the modular recirculating air distribution and heat extraction system 1200 can be arranged in stacks or tiers, analogously to the arrangement shown in Figure 3. Thus, the support 1224 may in some embodiments comprise a plurality of tiered plant canopies, with a plurality of tiered air return ducts disposed on dorsal sides of respective ones of the plant canopies and a plurality of air supply ducts disposed on ventral sides of respective ones of the plant canopies. In such embodiments, a roof of a lower tier may also function as a platform of an adjacent upper tier. Each tier will preferably have its own independent cabinet and HVAC system. In some embodiments, an air supply plenum and air return duct may extend from more than one side of a shared cabinet.

[0112] As noted above, the modular recirculating air distribution and heat extraction system 1200 shown in Figure 12 has the multipurpose cultivation carriers 700 and the air supply ducts 1232 extending substantially transverse to the direction of airflow through the air return duct 11034. This transverse arrangement may facilitate maintenance and harvesting of the plants while still enabling a large number of plants to be serviced by a single HVAC system. A technician can, once the light containment curtain 1274 is retracted, move along the length of the platform 1226, slide a multipurpose cultivation carrier 700 out, perform whatever steps are required, slide the multipurpose cultivation carrier 700 back into position, and then index over to the next multipurpose cultivation carrier 700.

[0113] The systems described herein are scalable and adaptable depending on the particular application. The positioning, spacing and size of the components, as well as the airflow rate and cooling configuration, will be dependent on the design, layout and requirements of the facility in which the plants are grown, as well as the type of plant(s).

[0114] An air distribution and heat extraction system according to aspects of the present disclosure can be incorporated into a controlled environmental stratification system adapted to enable intercropping techniques to be applied to indoor plant cultivation, with an efficient use of space. Plants of different kinds can be arranged within a single shelf of a plant grow system, with overlapping plant canopies at different heights, as will now be described.

[0115] Reference is now made to Figure 19, which schematically illustrates one embodiment of a particular method 1900 for plant cultivation that supports intercropping. The term “intercropping”, as used herein, refers to arrangements in which plants are positioned so that their canopies at least partially overlap, allowing a relatively larger number of plants to be cultivated within the same footprint than in the absence of such overlap. More particularly, shorter / smaller plants can be planted under the overlapping canopies of taller plants using space that traditionally will not support plant cultivation, effectively increasing the output of the grow system. Moreover, systems as described herein allow for simultaneous cultivation of plants having different requirements for temperature, humidity and vapor pressure deficit (VPD). A plurality of upper plants 1902 of a first plant type are provided. The upper plants 1902 have an upper plant canopy 1904. In addition, a plurality of lower plants 1906 of a second plant type are provided. The lower plants have a lower plant canopy 1908. The terms “lower” and “upper” as used in respect of the plants 1902, 1906 refer to the relative vertical locations of the plant canopies 1904, 1908 and not to other parts of the plants 1902, 1906. The lower plant canopy 1908 is disposed below the upper plant canopy 1904, with the upper plant canopy 1904 at least partially overlapping the lower plant canopy 1908. Of note, the terms “above” andbelow”, as used in reference to plant canopies, refer to relative vertical positions and do not require that the plant canopies overlap, nor do they refer to other parts of the plant.

[0116] Of note, the first plant type (of the upper plants 1902) is different from the second plant type (of the lower plants 1906). For example, the upper plants 1902 may be blueberries and the lower plants 1906 may be strawberries. This is merely an illustrative example, and is not limiting. For the purpose of this document, two plants are of a different “plant type” if they benefit from materially different temperature / humidity / VPD in terms of the crop for which they are cultivated by humans. The benefit may be a survival requirement; it may be that two plants have mutually exclusive temperature needs, where one plant type cannot survive in the environment in which another plant type can, and vice versa. Beyond mere survival, the benefit may also be, for example, a speed of plant or crop maturity, plant health, or a characteristic of the crop, such as size, shape and / or chemical composition (which may affect flavor, medicinal or other aspects of the crop). A “crop” may be, for example, all or part of a leaf, a stem, a fruit, a vegetable, a flower, a berry, a tuber or root, a nut, or a seed. Thus, blueberry plants and strawberry plants are examples of different plant types, because blueberries tend to prefer warmer temperatures than strawberries. However, plants that produce a common general kind of crop may still be considered different plant types. For example, different varieties of blueberry plant which are optimized for materially different temperatures would be considered different plant types even though they are all blueberry plants.

[0117] An upper canopy environment 1910 surrounding the upper plant canopy 1904 is maintained at an upper canopy air temperature, and a lower canopy environment 1912 surrounding the lower plant canopy 1908 is maintained at a lower canopy air temperature. The upper canopy air temperature is different from the lower canopy air temperature. For clarity, the term “upper” in the phrase “upper canopy air temperature” and the term “lower” in the phrase “lower canopy air temperature” refer not to the relative temperatures, but to the locations of the environments having those temperatures. Thus, the “upper canopy air temperature” may in some embodiments be a lower temperature than the “lower canopy air temperature”, although it is preferred that the “upper canopy air temperature” be higher than the “lower canopy air temperature” as this arrangement is generally less difficult to achieve. Preferably, the upper canopy environment 1910 also has a different humidity than the lower canopy environment 1912. There may be a gradient 1914 between the upper canopy environment 1910 and the lower canopy environment 1912; the gradient 1914 may be a temperature gradient, a humidity gradient, or a gradient in both temperature and humidity. The gradient 1914 may also be agradient in VPD. Notably, there is no physical barrier between the upper canopy environment 1910 and the lower canopy environment 1912 or isolating the upper canopy environment 1910 from the lower canopy environment 1912; the different conditions in the upper canopy environment 1910 and the lower canopy environment 1912 are maintained by control of the airflow and control of the physical state of the air, i.e. temp erature / humidity / VPD.

[0118] In preferred embodiments of the method 1900, the lower canopy environment 1912 is shielded against air spillover from the upper canopy environment 1910; some illustrative implementations of such shielding are described further below.

[0119] The first plant type is better suited to the upper canopy environment 1910 than the lower canopy environment 1912, and conversely the second plant type is better suited to the lower canopy environment 1912 than the upper canopy environment 1910. Notably, the upper canopy environment 1910 and the lower canopy environment 1912 are not necessarily static; each environment 1910, 1912 may vary in its characteristics, for example to simulate night and day, or to simulate a growing season, or for other purposes. For example, the first plant type may be blueberries and the second plant type may be strawberries, and the upper canopy environment 1910 may be warmer than the lower canopy environment 1912, but with variations to simulate night and day (with lighting bars furthering this simulation). In such an example, the upper canopy environment 1910 may be set to a “nighttime” temperature of about 16° to 20° C and a “daytime” temperature of about 25° to 30° C to support the blueberry plants and the lower canopy environment 1912 may be set to a “nighttime” temperature of about 10° to 15° C and a “daytime” temperature of about 18° to 23° C to support the strawberry plants. The relative humidity can be likewise controlled, for example to provide a “nighttime” humidity of 75% and a “daytime” humidity of 70% in the upper canopy environment 1910 to support the blueberry plants while simultaneously providing “nighttime” humidity of about 80-90% and a “daytime” humidity of about 60-65% in the lower canopy environment 1912 to support the strawberry plants. Likewise, the upper canopy environment 1910 and the lower canopy environment 1912 can be configured to have different VPD profiles. The upper canopy environment 1910 may be set to a “nighttime” VPD of about 0.46 to 0.59 kPa and a “daytime” VPD of about 1.0 kPa to support the blueberry plants and the lower canopy environment 1912 may be set to a “nighttime” VPD of about 0.4 kPa and a “daytime” VPD of about 0.9 to 1.0 kPa to support the strawberry plants. Characteristics of the upper canopy environment 1910 and / or the lower canopy environment 1912 may also be manipulated to selectively promote a regenerative growth phase or a vegetative growth phase of the plants therein. Preferably, thetemperature difference between the upper canopy environment 1910 and the lower canopy environment 1912 is at least one degree Celsius, more preferably at least two degrees Celsius and still more preferably at least three degrees Celsius.

[0120] The method illustrated in Figure 19 can also be used to provide root zone cooling. Root zone cooling provides a substantial benefit for certain plants. Some plants will only flower once their roots drop to a certain temperature. Additionally, for some plants, keeping the roots cooler than the plant canopy allows an increase in the temperature surrounding the canopy (potentially shortening the grow cycle) without overstressing the plant. Cooler roots also mean less evapotranspiration from the soil (or other growing media), which may also lower stress and improve moisture retention in the roots. In the illustrated embodiment shown in Figure 19, the upper plants 1902 are significantly taller than the lower plants 1906, and the root zones 1924 of the upper plants 1902 are disposed within the lower canopy environment 1912. Where the lower canopy environment 1912 is cooler than the upper canopy environment 1910, this results in a cooling of the root zones 1924 of the upper plants 1902.

[0121] While some embodiments may provide only two layers, e.g. upper plants 1902 and lower plants 1906, other embodiments may provide for three or more layers of plants. Multiple layers may share a common canopy environment and / or one or more layers may have their own dedicated canopy environment.

[0122] In the illustrative embodiment of the method 1900 shown in Figure 19, there is a plurality of intermediate plants 1916 having an intermediate plant canopy 1918. The term “intermediate” as used in this context, refer to the relative vertical locations of the plant canopies 1904, 1908, 1918. As can be seen in Figure 19, the intermediate plant canopy 1918 is disposed above the lower plant canopy 1908 and below the upper plant canopy 1904, and is therefore “intermediate” in vertical height between the lower plant canopy 1908 and the upper plant canopy 1904, which overlaps both the intermediate plant canopy 1918 and the lower plant canopy 1908. The terms “above”, “below” and “intermediate”, as used in reference to plant canopies, refer to relative vertical positions and do not require that the plant canopies overlap. Thus, it can be seen in Figure 19 that while the intermediate plant canopy 1918 is disposed above the lower plant canopy 1908 in terms of vertical height, the intermediate plant canopy 1918 does not overlap the lower plant canopy 1908. This is merely an illustrative embodiment, and in other embodiments the intermediate plant canopy may partially or entirely overlap the lower plant canopy.

[0123] In the embodiment shown in Figure 19, the intermediate plants 1916 are of the same plant type as the lower plants 1906, and the lower canopy environment 1912 surrounding the lower plant canopy 1908 is also maintained surrounding the intermediate plant canopy 1918, so that the lower plant canopy 1908 and the intermediate plant canopy 1918 share a common canopy environment, namely the lower canopy environment 1912.

[0124] Figure 19A shows an arrangement that is similar to that shown in Figure 19, except that the intermediate plants 1916A are of a third plant type that is different from both the first plant type and the second plant type, and an intermediate canopy environment 1920 is maintained surrounding the intermediate plant canopy 1918A. The intermediate canopy environment 1920 has an intermediate canopy air temperature that is different from both the upper canopy air temperature and the lower canopy air temperature. The humidity and / or VPD for the intermediate canopy environment 1920 may also be different from those of the lower canopy environment 1912 and / or the upper canopy environment 1910. In addition to the gradient 1914 between the upper canopy environment 1910 and the lower canopy environment 1912, there may also be a gradient 1922 between the lower canopy environment 1912 and the intermediate canopy environment 1920. Again, there is no physical barrier between any of the upper canopy environment 1910, the intermediate canopy environment 1920 and the lower canopy environment 1912 or isolating the upper canopy environment 1910 or the lower canopy environment 1912 from the intermediate canopy environment 1920; the different conditions in the upper canopy environment 1910, the intermediate canopy environment 1920, and the lower canopy environment 1912 are maintained by control of the airflow and physical properties of the supplied air (e.g. different amounts of cooling and reheating). Preferably, the temperature difference between the upper canopy environment 1910 and the intermediate canopy environment 1920, and between the intermediate canopy environment 1920 and the lower canopy environment 1912, is at least one degree Celsius, more preferably at least two degrees Celsius and still more preferably at least three degrees Celsius.

[0125] As with the method shown in Figure 19, the method shown in Figure 19A can also be used to provide root zone cooling. As can be seen in Figure 19 A, the upper plants 1902 are significantly taller than the lower plants 1906. The root zones 1924 of the upper plants 1902 are disposed within the lower canopy environment 1912, which may be cooler than the upper canopy environment 1910, resulting in a cooling of the root zones 1924 of the upper plants 1902. Also, the intermediate plants 1916A could be positioned with their root zones in the cooler lower canopy environment 1912, or in the gradient 1922 between the lower canopyenvironment 1912 and the intermediate canopy environment 1920, or in the intermediate canopy environment 1920, depending on the temperature desired.

[0126] Some illustrative apparatus for implementing the above method will now be described.

[0127] Figure 20 shows an illustrative canopy air supply regulator, indicated generally at reference 2000. The canopy air supply regulator 2000 comprises a hollow tube 2002 having an inlet end 2004 and an outlet end 2006. The inlet end 2004 is truncated obliquely relative to an axial direction of the tube 2002. An air concentrator scoop 2008 is carried by the hollow tube 2002 and protrudes from the truncated inlet end 2004 thereof. The truncated inlet end 2004 of the tube 2002 and the air concentrator scoop 2008 cooperate to define contours of an inlet aperture 2010 of the canopy air supply regulator 2000, and air concentrator scoop 2008 is selectively displaceable relative to the tube 2002 to adjust the contours of the inlet aperture 2010.

[0128] In the illustrated embodiment, the tube 2002 has an outwardly projecting annular flange 2012 which supports an O-ring 2014; the neck 2016 of the tube 2002 between the annular flange 2012 and the outlet end 2006 functions as a connector portion for coupling the canopy air supply regulator 2000 to various parts, as described further below. Locating marks 2018 are disposed on the annular flange 2012, facing toward the outlet end 2006.

[0129] In the illustrated embodiment, the air concentrator scoop 2008 comprises a resilient sheet 2024 that is ordinarily biased into a planar configuration. As shown in Figure 21A, in the planar configuration the illustrated embodiment of the resilient sheet 2024 has the shape of a rounded Moorish ogive 2026 with extended arms 2028 projecting from the base 2030 of the rounded Moorish ogive 2026. To form the canopy air supply regulator 2000, the resilient sheet 2024 is rolled into a scoop-ended inner tube 2032 as shown in Figure 21B. Although the arms 2028 are shown as overlapping, such overlap is not required. The scoop-ended inner tube 2032 is then slid into the hollow tube 2002, as shown in Figure 22. The bias of the resilient sheet 2024 toward the planar configuration gives the scoop-ended inner tube 2032 and tendency to outwardly unroll, which retains the scoop-ended inner tube 2032 in slidable frictional engagement with the inner surface 2034 of the hollow tube 2002. The inner surface 2034 of the hollow tube 2002 may be provided with an inwardly projecting annular flange 2036, which functions as a stop to limit travel of the scoop-ended inner tube 2032 into the hollow tube 2002. In other embodiments, other types of stops may be use to limit travel. Thus, as can be seen inFigure 22, in the illustrated embodiment, the air concentrator scoop 2008 is formed by a scoop- ended inner tube 2032 that is nested within the hollow tube 2002.

[0130] As noted above, air concentrator scoop 2008 is selectively displaceable relative to the tube 2002 to adjust the contours of the inlet aperture 2010. Because of the slidable frictional engagement of the scoop-ended inner tube 2032 with the inner surface 2034 of the hollow tube 2002, the scoop-ended inner tube 2032 is axially extendible from and retractable into, and axially rotatable within, the hollow tube 2002. Consequently, the air concentrator scoop 2008 is selectively axially extendible and retractable relative to the hollow tube 2002 to vary the extent by which the air concentrator scoop 2008 protrudes beyond the inlet end 2004, and is also selectively axially rotatable relative to the hollow tube 2002, and in particular the obliquely truncated inlet end 2004 of the hollow tube 2002. By selectively extending or retracting and / or rotating the scoop-ended inner tube 2032, relative to the hollow tube 2002, the shape formed by the combination of the air concentrator scoop 2008 and the obliquely truncated inlet end 2004 of the hollow tube 2002 can be modified through a wide range of variations. This enables the contours of the inlet aperture 2010 to be adjusted, so as to control the characteristics of airflow into the inlet aperture 2010 as well as influencing airflow past the inlet aperture 2010 when the canopy air supply regulator 2000 is disposed within an air supply plenum. The oblique truncation of the inlet end 2004 is preferred as it allows for use of the canopy air supply regulator 2000 without the air concentrator scoop 2008; so long as the air concentrator scoop 2008 will be used, the inlet end of the tube need not be truncated.

[0131] The rounded Moorish ogive shape of the resilient sheet 2024 is illustrative and not limiting; other suitable shapes are also contemplated. The resilient sheet used to form the air concentrator scoop can have a wide range of shapes depending on the airflow requirements. Also optionally, the inwardly projecting annular flange 2036 may be omitted or moved to enable the air concentrator scoop 2008 to be fully retracted (i.e. a zero protrusion from the obliquely truncated inlet end 2004 of the hollow tube 2002). Moreover, in alternate embodiments the air concentrator scoop 2008 may only be rotatable but not extendable and retractable, or only extendable and retractable but not rotatable, although these embodiments are less preferred. Further, while the illustrated embodiment shows the scoop-ended inner tube 2032 as being nested within the hollow tube 2002, in other embodiments a scoop -ended inner tube may slide along the outside of the hollow tube, although such embodiments are less preferred.

[0132] Some illustrative uses of the illustrated canopy air supply regulator 2000 will now be described.

[0133] Figures 23 A, 23B and 24 show how the illustrated canopy air supply regulator 2000 can be used in conjunction with canopy airflow nozzles 1272 and air curtain nozzles 1270. In the illustrated embodiment, the neck 2016 of the canopy air supply regulator 2000 functions as a connector portion thereof. In Figure 23 A, the neck 2016 of the canopy air supply regulator 2000 can be friction fit into one end of an extension tube 2340 whose other end is interengaged (e.g. friction fit) with the inlet 2342 of a canopy airflow nozzle 1272. The extension tubes can be of various lengths, allowing a canopy airflow nozzle 1272 to be situated at various elevations. In Figure 23B, the neck 2016 of the canopy air supply regulator 2000 can be friction fit directly into the inlet 2342 of a canopy airflow nozzle 1272. Figure 24 shows a similar arrangement for an air curtain nozzle 1270, where the neck 2016 of the canopy air supply regulator 2000 can be friction fit into the inlet 2442 of the air curtain nozzle 1270. To enable either a canopy airflow nozzle 1272 (with or without extension tube 2340) or an air curtain nozzle 1270 to be supplied from an air plenum, the canopy air supply regulator 2000 can be inserted (e.g. friction fit) into an aperture of an air supply plenum, with the outwardly projecting annular flange 2012 and O-ring 2014 cooperating to seal the plenum aperture into which the canopy air supply regulator 2000 is inserted. Note that in other embodiments, canopy airflow nozzles may have integral tubes of different lengths, obviating the need for an extension tube, or a telescoping extension tube of adjustable length may be provided.

[0134] As can be seen in Figures 23 A and 23B, in the illustrated embodiment each of the canopy airflow nozzles 1272 comprises an infundibular outlet seat 1273 in which an axially movable conical or frusto-conical outlet plug 1275 is received. By moving the outlet plug 1275 toward or away from the outlet seat 1273 (e.g. by threaded engagement and rotation), the size of the annular gap 1277 therebetween can be varied to control airflow and velocity. This control is preferably in addition to the control over airflow and velocity provided by selectively extending or retracting and / or rotating the scoop-ended inner tube 2032 and / or rotating the hollow tube 2002 of the canopy air supply regulator 2000 within the air supply plenum.

[0135] Figures 25A and 25B show how the canopy air supply regulators 2000 can be used in conjunction with a first illustrative plant carrier plenum 2500, which can also function as a plant carrier, as described further below. The illustrative plant carrier plenum 2500 is hollow and has upwardly sloping sides 2502 in which are formed a plurality of spaced -apart outletapertures 2504, with a longitudinally-extending upwardly-facing channel 2506 formed therein and adapted to receive plant containers, or alternatively blocks or elongate slabs of stonewool (plant growing media composed wholly or principally of mineral fibers), such as those offered under the trademark Grodan® by Rockwool International A / S having an address at Hovegaden 584 Hedehusene, Denmark DK 2640. The outlet apertures 2504 extend alongside the channels 2506. In addition, a plurality of inlet apertures 2508 are formed through the bottom 2510 of the plant carrier plenum 2500 and the longitudinal ends 2512 thereof are closed. The inlet apertures 2508 are adapted to receive the canopy air supply regulators 2000. Therefore, air suppled under pressure to the interior 2514 of the plant carrier plenum 2500 through the inlet apertures 2508 via the canopy air supply regulators 2000 will escape through the outlet apertures 2504. It is also contemplated that the plant carrier plenum may include integrally formed regulators.

[0136] As noted above, the contours of the inlet aperture 2010 of the canopy air supply regulator 2000 can be adjusted, so as to impact the characteristics of airflow into the inlet aperture 2010. In addition, the canopy air supply regulator 2000 itself can be rotated within the aperture in the air supply plenum, thereby changing the orientation of the inlet aperture 2010 relative to the airflow through the air supply plenum. This allows for more precise control of the airflow reaching the respective canopy airflow nozzles 1272 and air curtain nozzles 1270, as well as control over the airflow into the plant carrier plenum 2500 and through the outlet apertures 2504. The locating marks 2018 on the annular flange 2012 can assist in obtaining a desired rotational orientation.

[0137] Reference is now made to Figure 26, which shows an illustrative embodiment of a controlled environmental stratification system for intercropped plant cultivation configured to implement the method 1900 described in the context of Figure 19. The controlled environmental stratification system is denoted generally by reference 2600, and includes a cabinet 2604, which contains a similar integrated HVAC system to that described above in the context of Figure 18.

[0138] The controlled environmental stratification system 2600 comprises an air supply plenum 2650, which is in fluid communication with the interior of the cabinet 2604 at one end of the air supply plenum 2650 and closed at the other end. Although only a single air supply plenum 2650 is visible in Figure 26, the controlled environmental stratification system 2600 has a plurality of air supply plenums 2650 extending in parallel, as can be seen in Figure 28. Theair supply plenum 2650 forms a platform 2626, which functions as a support. The air supply plenum 2650 is configured to supply positive air pressure from the cabinet 2604, and has a series of spaced apart supply plenum outlet apertures 2652. The supply plenum outlet apertures 2652 are configured to receive the canopy air supply regulators 2000 with the outwardly projecting annular flange 2012 and O-ring 2014 forming a seal with the air supply plenum 2650. Thus, the platform 2626 formed by the air supply plenum 2650 can support canopy airflow nozzles 1272 and air curtain nozzles 1270 by inserting air supply regulators 2000 coupled to the canopy airflow nozzles 1272 and air curtain nozzles 1270 into the supply plenum outlet apertures 2652. The canopy airflow nozzles 1272 and air curtain nozzles 1270 will then be in fluid communication with the air supply plenum 2650 by way of the air supply regulators 2000.

[0139] Similarly, the platform 2626 formed by the air supply plenum 2650 can support plant carrier plenums 2500 by inserting air supply regulators 2000 coupled to the plant carrier plenums 2500 into the supply plenum outlet apertures 2652. It will be appreciated that to facilitate this, the spacing and positioning of the inlet apertures 2508 (Figure 25B) matches that of the supply plenum outlet apertures 2652. Thus, the air supply plenum 2650 is in fluid communication with a plurality of spaced-apart plant carrier plenums 2500 in which the lower canopy airflow outlets are formed by the outlet apertures 2504 (see Figures 25A and 25B). As can be seen in Figure 26, in the illustrated embodiment the plant carrier plenums 2500 extend substantially perpendicular to the air supply plenum 2650 and are disposed atop the platform 2626 formed thereby. It is also contemplated that the plant carrier plenums 2500 may be coupled to the air supply plenum 2650 without the use of the air supply regulators 2000, although this is less preferred.

[0140] In the illustrated embodiment the canopy airflow nozzles 1272 are coupled to the air supply regulators 2000 by way of respective extension tubes 2340. The canopy airflow nozzles 1272 are therefore elevated, and form a plurality of spaced apart upper canopy airflow outlets to which the air supply plenum 2650 is configured to supply positive air pressure via the air supply regulators 2000 and the extension tubes 2340. Similarly, the outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500 form a plurality of spaced apart lower canopy airflow outlets to which the air supply plenum 2650 is configured to supply positive air pressure via the air supply regulators 2000 and the interiors 2514 of the plant carrier plenum 2500. Thus, in the illustrated embodiment shown in Figure 26, a single air supply plenum 2650 supplies the positive air pressure to both the upper canopy airflow outlets (canopy airflownozzles 1272) and the lower canopy airflow outlets (outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500).

[0141] In addition, air curtain nozzles 1270 can be coupled in fluid communication with the air supply plenum 2650 via the air supply regulators 2000, and arranged along the outer edge of the air supply plenum 2650 along the length thereof, similarly to the arrangement described above in the context of Figure 12. The air curtain nozzles 1270 create an air curtain as described below.

[0142] As can be seen in Figure 26, the canopy airflow nozzles 1272 are in an elevated position, relative to the plant carrier plenums 2500. Accordingly, the upper canopy airflow outlets formed by the canopy airflow nozzles 1272 are arranged at an upper height, and the lower canopy airflow outlets formed by the outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500 are arranged at a lower height that is below the upper height.

[0143] In the illustrated embodiment, since the upper canopy airflow outlets are formed by adjustable canopy airflow nozzles 1272, airflow through the upper canopy airflow outlets is adjustable. In addition, by (for example) varying the length (or presence / absence) of the extension tubes 2340, the upper height (the height of the upper canopy airflow outlets formed by the adjustable canopy airflow nozzles 1272) may be adjusted. In other embodiments, the upper canopy airflow outlets may be formed by elements other than the canopy airflow nozzles 1272.

[0144] The illustrative controlled environmental stratification system 2600 shown in Figure 26 further comprises an upper air return duct 2634 positioned above the upper height, that is, above the upper canopy airflow outlets formed by adjustable canopy airflow nozzles 1272, and extending substantially parallel to the air supply plenum 2650. The upper air return duct 2634 is also positioned above the upper plant canopies 1904. The upper air return duct 2634 has a plurality of inlet apertures 2636 and is configured to apply negative air pressure above the upper canopy airflow outlets formed by adjustable canopy airflow nozzles 1272. The upper air return duct 2634 is configured to withdraw air supplied by both the upper canopy airflow outlets and the lower canopy airflow outlets. While only a single air return duct 2634 is exposed in Figure 26, by reference to Figure 28 it can be seen that the illustrative controlled environmental stratification system 2600 includes two air return ducts 2634 extending in parallel.

[0145] The illustrative controlled environmental stratification system 2600 shown in Figure 26 is also provided with agricultural lighting. This includes a lower canopy agricultural lighting system and an upper canopy agricultural lighting system. In the illustrated embodiment the lower canopy agricultural lighting system and the upper canopy agricultural lighting system each comprise a respective plurality of spaced-apart lighting bars 2612, 2638 such as for example MetaRail™ or HyperRail™ lighting bars suspended from the upper air return duct 2634.

[0146] The lower canopy lighting bars 2612 forming the lower canopy agricultural lighting system are positioned between the lower height and the upper height, that is, between the lower canopy airflow outlets formed by the outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500 and the upper canopy airflow outlets formed by the canopy airflow nozzles 1272. The upper canopy lighting bars 2638 forming the upper canopy agricultural lighting system are positioned above the upper height, that is, above the upper canopy airflow outlets formed by the canopy airflow nozzles 1272, and below the upper air return duct 2634. It follows that the upper canopy lighting bars 2638 are also positioned above the lower height, i.e. above the lower canopy airflow outlets formed by the outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500. The upper air return duct 2634 is also positioned above the upper canopy lighting bars 2638, which may be suspended from the upper air return duct 2634.

[0147] As noted above, a longitudinally-extending upwardly-facing channel 2506 is formed in each of the plant carrier plenums 2500, with the channel 2506 adapted to receive plant containers, stonewool blocks or a stonewool slab. The lower plants 1906 are received in the channels 2506, with the lower plant canopy 1908 generally positioned above the lower canopy airflow outlets formed by the outlet apertures 2504 in the sides 2502 of the plant carrier plenums 2500. The lower plant canopies 1908 are also disposed below the lower canopy lighting bars 2612 so that light therefrom will be applied to the lower plant canopy 1908. Planters 2640 are provided for the upper plants 1902, and the planters 2640 are positioned between the plant carrier plenums 2500, with the upper plant canopies 1904 positioned above the lower canopy lighting bars 2612 (and hence above the lower plant canopies 1908), between the upper canopy airflow outlets formed by the canopy airflow nozzles 1272 and the upper canopy lighting bars 2638. This arrangement allows for the creation of an upper canopy environment 1910 that is distinct from the lower canopy environment 1912, as shown in Figure 19, by suitable manipulation of the canopy air supply regulators 2000.

[0148] Figure 26A shows how a plurality of the controlled environmental stratification systems 2600 may be arranged in vertical tiers. While only two tiers are shown, there may be three or more tiers.

[0149] Reference is now made to Figures 27 and 28, which show the various airflows that create the upper canopy environment 1910 and the lower canopy environment 1912. Figure 27 is a side cross-sectional view and Figure 28 is an end cross-sectional view.

[0150] Treated (e.g. cooled and dehumidified) air 2702 enters the air supply plenum 2650 from the cabinet 2604. From the air supply plenum 2650, the treated air 2702 is collected by the canopy air supply regulators 2000 and fed into the plant carrier plenums 2500 and through the extension tubes 2340 to the canopy air supply nozzles 1272. The canopy air supply regulators 2000 depend downwardly into the interior volume of the air supply plenum 2650. The canopy air supply regulators 2000 can compensate for large chaotic turbulence that can create dead, stagnant pockets of air within the air supply plenum 2650 In addition, to some extent adjustment of the airflow through the nozzles 1272 can also compensate for pressure drop along the length of the air supply plenum 2650. Extending the air concentrator scoop 2008 downward or upward within the air supply plenum 2650 allows the inlet aperture 2010 of the canopy air supply regulator 2000 to be positioned within a moving pocket of air. Additionally, by rotating the air concentrator scoop 2008 into or out of the airflow path within the air supply plenum 2650, the volume of air entering the inlet aperture 2010 and reaching the nozzles 1270, 1272 and the plant carrier plenums 2500 can be increased, decreased, or stopped. The canopy air supply regulator 2000 may also create turbulence to assist in maintaining a consistent airflow along the entire length of the air supply plenum 2650. Conventional ducts without canopy air supply regulators and without adjustable nozzles, for example soft inflatable “sockducts”, would not be able to get the air to move far enough into the canopy and cannot adjust for lengthwise variations in flow and velocity; the velocity at exit would drop precipitously after the air has travelled only a very short distance.

[0151] As the treated air 2702 flows into the plant carrier plenums 2500 at a positive air pressure, it escapes through the outlet apertures 2504 and moves toward the lower plant canopies 1908 of the lower plants 1906 disposed in the channels 2506. This air is drawn upward toward and into the inlet apertures 2636 of the upper air return duct by the negative air pressure therein. The positive air pressure is thus applied on the ventral side of the lower plant canopies 1908 and the negative air pressure is applied on the dorsal side of the lower plantcanopies 1908. By this arrangement, the air is drawn from the ventral side of the lower plant canopies 1908 across the lower plant canopies 1908 and past the dorsal side thereof to withdraw heat from the lower canopy lighting bars 2612 along with humidity from plant respiration. The warmed and humidified air 2704 is then recycled to the cabinet 2604 for treatment and return to the air supply plenum 2650. The airflow through the outlet apertures 2504 of the plant carrier plenums 2500 can be controlled by adjustment of the canopy air supply regulators 2000, so as to selectively control the temperature and / or humidity and / or VPD of the air surrounding the lower plant canopies 1908. In addition, the airflow through the plant carrier plenums 2500 may provide root zone cooling for the lower plants 1906; optionally outlets may be disposed within the channels 2506 to increase this effect, which would be particularly effective with stonewool.

[0152] Similarly, as the treated air 2702 flows through the extension tubes 2340 to the nozzles 1272 at a positive air pressure, it escapes through the nozzles 1272 and moves toward the upper plant canopies 1904 of the upper plants 1902 disposed in the planters 2640. This air is drawn upward toward and into the inlet apertures 2636 of the upper air return duct by the negative air pressure therein. Accordingly, positive air pressure is applied on the ventral side of the upper plant canopies 1904, with negative air pressure applied on the dorsal side of the upper plant canopies 1904. The air is thus drawn from the ventral side of the upper plant canopies 1904 through the upper plant canopies 1904 and past the dorsal side thereof to withdraw heat from the upper canopy lighting bars 2638 along with humidity from plant respiration and then the warmed and humidified air 2704 is returned to the cabinet 2604. The airflow into the extension tubes 2340 can be controlled by adjustment of the canopy air supply regulators 2000. Because the upper canopy airflow outlets are formed by adjustable canopy airflow nozzles 1272, airflow velocity through the upper canopy airflow outlets is adjustable. By adjusting the flow and / or velocity of treated air through the canopy airflow nozzles 1272 that form the upper canopy airflow outlets, the temperature and / or humidity and / or VPD of the air surrounding the upper plant canopies 1904 can be controlled. Optionally, the planters 2640 may include inlets connected in fluid communication with the air supply plenum 2650, for example by way of the canopy air supply regulators 2000, to provide airflow through the planters 2640 for root zone cooling.

[0153] Of note, the air emerging from the dorsal side of the lower plant canopies 1908 will have been warmed by the lower canopy lighting bars 2612 and humidified by respiration of the lower plants 1906. By carefully modulating the airflow through the canopy airflow nozzles 1272 forming the upper canopy airflow outlets, the contribution of the heat and humidity fromthe air emerging from the dorsal side of the lower plant canopies 1908 to the environment surrounding the upper plant canopies 1904 can be controlled so as to be different from the environment surrounding the lower plant canopies 1908. Typically, although not necessarily, the environment surrounding the upper plant canopies 1904 will be warmer and potentially more humid than the environment surrounding the lower plant canopies 1908, with the upper plants 1902 being selected to be better adapted to warmer and more humid air than the lower plants 1906. In other cases, the environment surrounding the upper plant canopies 1904 could in fact be drier, for example, younger plants in vegetative growth may not produce much humidity. Humidity is also impacted by the heat from the agricultural lighting system.Notably, the airflow through the canopy airflow nozzles 1272 forming the upper canopy airflow outlets can be modulated by adjusting the canopy airflow nozzles 1272 in conjunction with adjustment of the canopy air supply regulators 2000.

[0154] As noted above, air curtain nozzles 1270 can be coupled in fluid communication with the air supply plenum 2650 via the air supply regulators 2000, and arranged along the outer edge of the air supply plenum 2650 along the length thereof. As shown in Figure 28, the air curtain nozzles 1270 generate an air curtain 2802 extending along the outer edge of the air supply plenum 2650 to enclose the upper canopy environment and the lower canopy environment and inhibit air from escaping those environments; the air curtain 2802 also functions as a shield and is configured to inhibit air spillover from the canopy airflow nozzles 1272 forming the upper canopy airflow outlets toward the outlet apertures 2504 in the plant carrier plenum 2500 that form the lower canopy airflow outlets. This arrangement is particularly advantageous where the environment surrounding the upper plant canopies 1904 is cooler than the environment surrounding the lower plant canopies 1908, since the cooler air will tend to sink. Even where the environment surrounding the upper plant canopies 1904 is warmer than the environment surrounding the lower plant canopies 1908, the use of a shield against spillover can still reduce energy consumption by avoiding waste of treated air. Although in the illustrated embodiment it is an air curtain 2802 that provides the shield, in other embodiments the shield may take the form of a physical deflector, such as a plate or a sheet, either of which may be fixed or retractable, or may be omitted. Thus, while the air curtain nozzles 1270 and air curtain 2802 are preferred, they may be omitted from some embodiments without departing from the scope of the present disclosure. In yet other embodiments, the air curtain may cooperate with physical shields and / or a retractable physical curtain, such as a retractable light containment curtain.

[0155] The controlled environmental stratification system 2600 shown in Figures 26 to 28 may also be provided with an irrigation / fertigation system and / or drainage arrangement similar to those described above.

[0156] As noted above and as can be seen in Figure 28, in the illustrated embodiment the controlled environmental stratification system 2600 has a plurality of air supply plenums 2650 extending in parallel, as can be seen in Figure 28. In some optional embodiments, an additional reheat coil may be associated with one of the air supply plenums 2650 so that the air on one side of the controlled environmental stratification system is at a different temperature than on the other side; in such an embodiment an air curtain or physical barrier may be interposed between the two sides. Such an arrangement may be used in association with an integrated HVAC system similar to that described above in the context of Figure 18, or with bulk treated air.

[0157] Figures 27A and 27B show sectional side views of a modified version of the controlled environmental stratification system 2600 shown in Figure 26 in which, instead of using the plant carrier plenums 2500, a second set of canopy airflow nozzles 1272 form the lower canopy airflow outlets. This is achieved by coupling the canopy airflow nozzles 1272 directly to the air supply regulators 2000 without the extension tubes 2340 (or by using shorter extension tubes), so that the air supply plenum 2650 is configured to supply positive air pressure directly to the canopy airflow nozzles 1272 forming the lower canopy airflow outlets via the canopy air supply regulators 2000. Thus, as can be seen in Figure 27A, the first set of canopy airflow nozzles 1272 are in an elevated position, relative to the second set of canopy airflow nozzles 1272, by way of the extension tubes 2340. Accordingly, the upper canopy airflow outlets formed by the first set of canopy airflow nozzles 1272 are arranged at an upper height, and the lower canopy airflow outlets formed by second set of canopy airflow nozzles 1272 are arranged at a lower height that is below the upper height. By selectively positioning (e.g. rotating) the canopy air supply regulators 2000 within the supply plenum outlet apertures 2652 and configuring the air concentrator scoop 2008 thereof, different mass flows into the first set of canopy airflow nozzles 1272 and into the second set of canopy airflow nozzles 1272 can be provided despite the fact that the positive air pressure comes from a common canopy air supply plenum.Moreover, as can be seen in the enlargements shown in Figure 27A, in the illustrated configuration the first set of canopy airflow nozzles 1272 arranged at the upper height have relatively less volume flow than the second set of canopy airflow nozzles 1272 arranged at the lower height; the reverse configuration is also possible. By providing for different airflowsthrough the first set of canopy airflow nozzles 1272 than through the second set of canopy airflow nozzles 1272, an upper canopy environment 1910 that is distinct from the lower canopy environment 1912 can be achieved, as shown in Figure 27B. In particular, a greater flow rate of air at a fixed temperature and humidity will provide for a greater cooling capacity, and conversely a lesser flow rate of air at the same fixed temperature and humidity will provide for a lesser cooling capacity. Thus, even though the air originates from a common air supply plenum and hence has a common temperature and humidity, differential cooling can be achieved by providing a different rate of airflow at the upper height than at the lower height. The heat output of the upper canopy lighting bars 2638 and the lower canopy lighting bars 2612 will also affect the cooling rate. In the illustrated configuration, the canopy airflow nozzles 1272 at the lower height are configured for greater mass flow than the canopy airflow nozzles 1272 at the upper height. In this configuration, so long as the greater cooling capacity associated with the increased mass flow from the lower canopy airflow nozzles 1272 is sufficient to overcome the heat contribution from the lower canopy lighting bars 2612, it is possible to maintain the lower canopy environment 1912 cooler than the upper canopy environment 1910. Conversely, by configuring the canopy airflow nozzles 1272 at the upper height for greater mass flow than the canopy airflow nozzles 1272 at the lower height, so long as the greater cooling capacity can overcome the heat contribution from the canopy lighting bars 2612, 2638, it is possible to maintain the upper canopy environment 1910 cooler than the lower canopy environment 1912. However, this arrangement is significantly less efficient and is less preferred than maintaining the lower canopy environment 1912 cooler than the upper canopy environment 1910.

[0158] Where the differences between the various canopy environments will exceed the differential cooling that is possible where the positive air pressure supplied to the upper canopy airflow outlets and the lower canopy airflow outlets originates from a single common air supply plenum at the same temperature and humidity, an additional supply of cooler air is required. With reference now to Figures 29A through 34C, a controlled environmental stratification system having multiple air supply plenums will now be described. The use of multiple plenums enables the supply of positive air pressure to the upper canopy airflow outlets at a different temperature and humidity than that of the positive air pressure supplied to the lower canopy airflow outlets.

[0159] Reference is first made to Figures 29A and 29B, which show an illustrative version2900 of the plant carrier plenum which differs from the version 2500 of the plant carrier plenumshown in Figures 25A and 25B. The plant carrier plenum 2900 shown in Figures 29A and 29B is similar to the plant carrier plenum 2500 shown in Figures 25A and 25B, with like reference numerals denoting like features but with the prefix “29” instead of “25”. However, in the plant carrier plenum 2900 shown in Figures 29A and 29B there is a single inlet aperture 2908 formed in one of the longitudinal ends 2912, rather than in the bottom 2910. The inlet aperture 2908 is adapted to receive one of the canopy air supply regulators 2000. The plant carrier plenum 2900 shown in Figures 29A and 29B is adapted for use with a controlled environmental stratification system for intercropped plant cultivation having more than one air supply plenum, as will now be described.

[0160] Reference is now made to Figure 30, which shows another illustrative embodiment of a controlled environmental stratification system for plant cultivation that is configured to implement the method 1900 described in the context of Figure 19. The controlled environmental stratification system shown in Figure 30 is denoted generally by reference 3000, and is similar in many respects to the controlled environmental stratification system 2600 shown in Figures 26 through 28. Thus, like reference numerals denote like features, but with the prefix “30” rather than “26”. However, the controlled environmental stratification system 3000 shown in Figure 30 differs from the controlled environmental stratification system 2600 shown in Figure 26 in that it has two air supply plenums and two air return ducts, with corresponding modification to the integrated HVAC system.

[0161] The controlled environmental stratification system 3000 shown in Figure 30 implements an embodiment of the method 1900 shown in Figure 19 in which there is a plurality of intermediate plants 1916 having an intermediate plant canopy 1918. As can be seen in Figure 33C, the intermediate plant canopy 1918 is disposed above the lower plant canopy 1908 and below the upper plant canopy 1904, and is therefore “intermediate” in vertical height between the lower plant canopy 1908 and the upper plant canopy 1904, which overlaps both the intermediate plant canopy 1918 and the lower plant canopy 1908. In the embodiment shown in Figures 30 to 34C, the intermediate plants 1916 are of the same type as the lower plants 1906, and the lower canopy environment 1912 (Figure 19) surrounding the lower plant canopy 1908 is also maintained surrounding the intermediate plant canopy 1918, so that the lower plant canopy 1908 and the intermediate plant canopy 1918 share a common canopy environment.

[0162] Referring again to Figure 30, the controlled environmental stratification system 3000 comprises an upper canopy air supply plenum 3050. Of note, the term “upper canopy air supplyplenum” refers to the plenum that supplies air to an upper plant canopy (e.g. upper plant canopy 1904), and not to the position of the plenum itself. At one end thereof, the upper canopy air supply plenum 3050 is in fluid communication with the interior of the cabinet 3204 containing the integrated HVAC system; the upper canopy air supply plenum 3050 is closed at the other end. Although only a single upper canopy air supply plenum 3050 is visible in Figure 30, the controlled environmental stratification system 3000 has a plurality of upper canopy air supply plenums 3050 extending in parallel, as can be seen in Figures 34A to 34C. The upper canopy air supply plenum 3050 forms a platform 3026 that can serve as a support. The upper canopy air supply plenum 3050 is configured to supply positive air pressure from the cabinet 3204, and has a series of spaced apart upper canopy supply plenum outlet apertures 3052, which are configured to sealingly receive the canopy air supply regulators 2000. The platform 3026 formed by the upper canopy air supply plenum 3050 can support canopy airflow nozzles 1272 and air curtain nozzles 1270 by inserting air supply regulators 2000, coupled to the canopy airflow nozzles 1272 (via the extension tubes 2340), and to the air curtain nozzles 1270, into the supply plenum outlet apertures 3052. The canopy airflow nozzles 1272 and the air curtain nozzles 1270 will then be in fluid communication with the upper canopy air supply plenum 3050 by way of the air supply regulators 2000. Accordingly, the upper canopy air supply plenum 3050 is configured to supply a first positive air pressure to the upper canopy airflow outlets formed by the canopy airflow nozzles 1272, as well as to the air curtain nozzles 1270, which are arranged along the outer edge of the upper canopy air supply plenum 3050 along the length thereof, similarly to the arrangement described above in the context of Figure 26.Because the canopy airflow nozzles 1272 are coupled to the air supply regulators 2000 by way of respective extension tubes 2340, the canopy airflow nozzles 1272 are elevated. These canopy airflow nozzles 1272 form a plurality of spaced apart upper canopy airflow outlets to which the upper canopy air supply plenum 3050 is configured to supply positive air pressure via the air supply regulators 2000 and extension tubes 2340. In the illustrated embodiment, since the upper canopy airflow outlets are formed by adjustable canopy airflow nozzles 1272, airflow through the upper canopy airflow outlets is adjustable. In other embodiments, however, the upper canopy airflow outlets may be formed by elements other than the canopy airflow nozzles 1272. In addition, by (for example) varying the length (or presence / absence) of the extension tube 2340, the upper height (the height of the upper canopy airflow outlets formed by the adjustable canopy airflow nozzles 1272) may be adjusted. This allows for the upper canopy airflow outlets to be positioned in the correct location to supply air to the upper canopy. It isvery much preferable to use adjustable canopy airflow nozzles and to provide for adjustment of the vertical position of the adjustable canopy airflow nozzles. Adjustment of vertical position may be achieved, for example, by extension tubes of various lengths, different canopy airflow nozzles having integral tubes of different lengths (obviating the need for an extension tube), telescoping extension tubes of adjustable length, or canopy airflow nozzles having integral telescoping tubes.

[0163] The controlled environmental stratification system 3000 further comprises a lower canopy air supply plenum 3054 (see also Figure 31). Of note, the term “lower canopy air supply plenum” refers to the plenum that supplies air to a lower plant canopy (e.g. lower plant canopy 1908), and not to the position of the plenum itself. One end of the lower canopy air supply plenum 3054 is in fluid communication with the interior of the cabinet 3204 containing the integrated HVAC system and the other end of the lower canopy air supply plenum 3054 is closed. As can be seen in Figures 34A and 34C, in the illustrated embodiment a single lower canopy air supply plenum 3054 feeds both sides of the controlled environmental stratification system 3000; other embodiments may have a plurality of lower canopy air supply plenums 3054 extending in parallel. The lower canopy air supply plenum 3054 is configured to supply a second positive air pressure, and has a series of spaced apart lower canopy supply plenum outlet apertures 3056, which are configured to sealingly receive the canopy air supply regulators 2000.

[0164] In the illustrated embodiment, while the upper canopy air supply plenum 3050 is substantially wider than its height, the lower canopy air supply plenum 3054 is substantially taller than its width, and is positioned atop the platform 3026 formed by the upper canopy air supply plenum 3050 so that the two upper canopy air supply plenums 3050 and the lower canopy air supply plenum 3054 together form an inverted “T” shape. This is best seen in Figures 34A to 34C. In other embodiments, the lower canopy air supply plenum 3054 may be disposed between the two upper canopy air supply plenums 3050. As was noted above, the term “upper canopy air supply plenum” refers to the plenum that supplies air to an upper plant canopy and the term “lower canopy air supply plenum” refers to the plenum that supplies air to a lower plant canopy; as used in reference to supply plenums the terms “upper canopy” and “lower canopy” do not imply anything about the position of the plenum. Indeed, in the inverted “T” shaped arrangement shown in Figures 30 to 34C, the lower canopy air supply plenum 3054, that is, the plenum that supplies air to the lower plant canopies, is in fact positioned above the upper canopy air supply plenums 3050 that supply the upper plant canopies. The upper canopyair supply plenums 3050 extend substantially in parallel with the lower canopy air supply plenum 3054. This is merely one illustrative embodiment, and is not limiting.

[0165] The lower canopy air supply plenum 3054 is in fluid communication with a plurality of the plant carrier plenums 2900 of the type shown in Figures 29A and 29B and configured to supply positive air pressure thereto. Some of the plant carrier plenums 2900 are supported on the platform 3026 formed by the upper canopy air supply plenum 3050, positioned similarly to the arrangement shown in Figures 26 to 30, and other plant carrier plenums 2900 are supported on the planters 2640 that carry the upper plants 1902. The plant carrier plenums 2900 supported on the platform 3026 carry the lower plants 1906 and the plant carrier plenums 2900 supported on the planters 2640 carry the intermediate plants 1916. In both cases, the lower canopy supply plenum outlet apertures 3056 are configured to sealingly receive the canopy air supply regulators 2000 extending from the inlet aperture 2908 formed in one of the longitudinal ends 2912 of the plant carrier plenums 2900. This arrangement is shown in Figure 31 for one of the plant carrier plenums 2900 supported on the platform 3026; a similar arrangement is used for the plant carrier plenums 2900 that are supported on the planters 2640. The use of the vertically extending lower canopy air supply plenum 3054, in conjunction with plant carrier plenums 2900 for which the inlet apertures 2908 are formed in one of the longitudinal ends 2912, rather than in the bottom 2910, allows for the plant carrier plenums 2900 to be placed atop the planters 2640. This allows for densification of the lower plants 1906 and the lower plant canopy 1908 with the intermediate plants 1916 and the intermediate plant canopy 1918.

[0166] As can be seen in Figure 30, the canopy airflow nozzles 1272 are in an elevated position, relative to the plant carrier plenums 2900. Accordingly, the upper canopy airflow outlets formed by the canopy airflow nozzles 1272 are arranged at an upper height, and the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900 are arranged at a lower height that is below the upper height.

[0167] Similarly to the arrangement shown in Figures 26 to 30, the controlled environmental stratification system 3000 shown in Figures 30 to 34C also comprises an upper air return duct 3034 positioned above the upper height, that is, above the upper canopy airflow outlets formed by the adjustable canopy airflow nozzles 1272, and extending substantially parallel to the upper canopy air supply plenum 3050 and the lower canopy air supply plenum 3054. While only a single air return duct 3034 is exposed in Figure 30, by reference to Figures 34A to 34C it can be seen that the illustrative controlled environmental stratification system 3000 includes two airreturn ducts 3034 extending in parallel to one another; in other embodiments there may be a single upper air return duct. The upper air return duct 3034 has a plurality of upper duct inlet apertures 3036 (see Figure 30) and is configured to apply negative air pressure above the upper canopy airflow outlets formed by the adjustable canopy airflow nozzles 1272. Since the adjustable canopy airflow nozzles 1272 are disposed above the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900, the upper air return duct 3034 is necessarily also configured to apply negative air pressure above the lower canopy airflow outlets formed by the outlet apertures 2904.

[0168] Additionally, the controlled environmental stratification system 3000 further comprises a lower air return duct 3058 positioned between the lower height and the upper height, that is, between the upper canopy airflow outlets formed by the canopy airflow nozzles 1272 and the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900. The lower air return duct 3058 is configured to apply negative air pressure above the lower canopy airflow outlets and below the upper canopy airflow outlets, and includes a plurality of lower duct inlet apertures 3060. Accordingly, the air supplied by the upper canopy airflow outlets formed by the canopy airflow nozzles 1272 will be primarily withdrawn by the upper air return duct 3034 and the air supplied by the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900 will primarily be withdrawn by the lower air return duct 3058.

[0169] As best seen in Figure 31, in the illustrated embodiment the lower canopy air supply plenum 3054 and the lower air return duct 3058 are disposed within a common housing 3102, with the lower air return duct 3058 positioned above the lower canopy air supply plenum 3054 and separated therefrom by a divider 3104 extending through the housing 3102. Consequently, the lower duct inlet apertures 3060 are located above the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900. The air supplied at positive pressure in the lower canopy air supply plenum 3054 enters the plant carrier plenums 2900 via the canopy air supply regulator 2000 and inlet aperture 2908 and then flows through the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900, through the lower plant canopy 1908 and then through the lower duct inlet apertures 3060 into the lower air return duct 3058.

[0170] Reference is now made to Figure 32, which shows the HVAC system as adapted for the controlled environmental stratification system 3000 shown in Figure 30, which includes amodular recirculating air distribution and heat extraction system comprising an integrated HVAC system.

[0171] The cabinet 3204 forms a recirculation chamber 3216 connecting the upper air return duct 3034 and the lower air return duct 3058 in fluid communication with the upper canopy air supply plenum 3050 and the lower canopy air supply plenum 3054. An air circulation mechanism is formed by two fans 3218LC, 3218UC (other air circulation mechanisms are also contemplated), and is configured to draw air from the upper air return duct 3034 and the lower air return duct 3058. In the illustrated embodiment, the lower air return duct 3058 merges with the upper air return duct 3034 via a passage 3290 adjacent the cabinet 3204 so that the airflow from both the lower air return duct 3058 and the upper air return duct 3034 enters the cabinet 3204 via a common cabinet air inlet 3298. A cooling coil 3242 adapted to remove moisture is disposed in the recirculation chamber 3216 formed by the cabinet 3204. One of the fans is an upper canopy air supply fan 3218UC positioned and configured to supply positive air pressure to the upper canopy air supply plenum 3050 and the other one of the fans is a lower canopy air supply fan 3218LC positioned and configured to supply positive air pressure to the lower canopy air supply plenum 3054. Each of the fans 3218LC, 3218UC is co-located with a respective reheat coil 3244LC, 3244UC, and the cooling coil 3242 is positioned upstream of the fans 3218LC, 3218UC and reheat coils 3244LC, 3244UC. More particularly, an upper canopy air supply reheat coil 3244UC is disposed adjacent to the upper canopy air supply fan 3218UC and a lower canopy air supply reheat coil 3244LC is disposed adjacent to the lower canopy air supply fan 3218LC. The fans 3218LC, 3218UC and the reheat coils 3244LC, 3244UC are arranged in parallel. The upper canopy air supply reheat coil 3244UC receives cooled, dehumidified air from the cooling coil 3242 and reheats the cooled, dehumidified air to a first temperature having a first humidity and supplies the reheated air at the first temperature and humidity to the upper canopy air supply plenum 3050. Similarly, the lower canopy air supply reheat coil 3244UC receives cooled, dehumidified air from the cooling coil 3242 and reheats the cooled, dehumidified air to a second temperature having a second humidity and supplies the reheated air at the second temperature and humidity to the lower canopy air supply plenum 3054. Importantly, the first temperature and the second temperature may be different from one another and the first humidity and the second humidity may be different from one another.

[0172] Thus, air that is moved by the upper canopy air supply fan 3218UC into the upper canopy air supply plenum 3050 will pass through upper canopy air supply reheat coil 3244UC, and air that is moved by the lower canopy air supply fan 3218LC into the lower canopy airsupply plenum 3054 will pass through the lower canopy air supply reheat coil 3244LC. The use of two different fans 3218LC, 3218UC and two different reheat coils 3244LC, 3244UC allows air to be provided to the upper canopy air supply plenum 3050 at a different temperature and / or pressure and / or humidity from the air provided to the lower canopy air supply plenum 3054.

[0173] The cooling coil 3242 and the reheat coils 3244LC, 3244UC may each have respective modulating valves to regulate fluid flow therethrough, with a control system 3248 coupled thereto and adapted to independently regulate fluid flow through the cooling coil 3242 and each of the reheat coils 3244LC, 3244UC and to independently control the speed of the fans 3218LC, 3218UC. The control system 3248 may be coupled to thermostatic, CO2 or other sensors for environmental control, and to the modulating valves, as well as to bypass valves or other valves (e.g. three-way valves for load control), among others, to control the flow rate, and to control the amount of cooling and reheating. These arrangements will be known to one of ordinary skill in the art, now informed by the present disclosure. The control system 3248 may comprise, for example, a proportional-integral-derivative (PID) controller. Couplings between the control system 3248 and the various components are omitted from Figure 32 to avoid cluttering the illustration; suitable couplings will be apparent to one of ordinary skill in the art, now informed by the present disclosure.

[0174] Thus, the air circulation mechanism formed by the fans 3218LC, 3218UC pulls untreated air through the lower air return duct 3058 and the upper air return duct 3034 into the cabinet 3204 to apply the negative air pressure above the upper canopy airflow outlets and the lower canopy airflow outlets. The air circulation mechanism formed by the fans 3218LC, 3218UC further pushes treated air through the upper canopy air supply plenum 3050 to supply the positive air pressure to the upper canopy airflow outlets and through the lower canopy air supply plenum 3054 to supply the positive air pressure to the lower canopy airflow outlets.

[0175] In a preferred embodiment, an air-to-air heat exchanger 3280 is disposed in the cabinet 3204, interposed in the airflow path 3282 through the cabinet 3204. The illustrated air-to-air heat exchanger 3280 is a plate-to-plate heat exchanger but this is merely illustrative and not intended to be limiting. The air-to-air heat exchanger 3280 is configured to have a first heat exchange path 3284 upstream of the cooling coil 3242 (interposed between the common cabinet air inlet 3298 and the cooling coil 3242) and a second heat exchange path 3286 downstream of the cooling coil 3242 and upstream of the fans 3218LC, 3218UC and reheat coils 3244LC,3244UC (i.e. the second heat exchange path 3286 is interposed in the cooled airflow path 3288 between the cooling coil 3242, on the one hand, and the fans 3218LC, 3218UC and reheat coils 3244LC, 3244UC, on the other hand).

[0176] The airflow path 3282 through the cabinet 3204 carries the air from the common cabinet air inlet 3298 through the first heat exchange path 3284 of the air-to-air heat exchanger 3280, then through the cooling coil 3242, and then through the second heat exchange path 3286 of the air-to-air heat exchanger 3280, and then into a bifurcation zone 3299. From the bifurcation zone 3299, the upper canopy air supply fan 3218UC moves some of the air through the upper canopy air supply reheat coil 3244UC into the upper canopy air supply plenum 3050 and the lower canopy air supply fan 3218LC moves some of the air through the lower canopy air supply reheat coil 3244LC into the lower canopy air supply plenum 3054. As with the HVAC system shown in Figure 18, in the HVAC system shown in Figure 32 the air-to-air heat exchanger 3280 transfers heat from the air entering the common cabinet air inlet 3298 and simultaneously pre-cools the air drawn from the plant canopies 1904, 1908 upstream of the cooling coil 3242 and preheats the air between the cooling coil 3242 and the reheat coils 3244LC, 3244UC. The pre-heated air then passes to the reheat coils 3244LC, 3244UC, which further increase the air temperature to the desired set point for each of the lower canopy air supply plenum 3054 and the upper canopy air supply plenum 3050.

[0177] Reheat energy for the reheat coils 3244LC, 3244UC may be supplied from a chiller (external to the cabinet 3204) via a hot gas bypass loop. The air-to-air heat exchanger 3280 allows reheat coils 3244LC, 3244UC and the cooling coil 3242 to be of relatively smaller physical size while maintaining full cooling capacity, and may also enable relative reduction in the size of the associated chiller system as well as a relative reduction in power consumption.

[0178] While a single cooling coil 3242, a single upper canopy air supply reheat coil 3244UC and a single lower canopy air supply reheat coil 3244LC are shown, in other embodiments there may be more than one cooling coil and / or upper canopy air supply reheat coil and / or lower canopy air supply reheat coil.

[0179] Although not shown in Figure 32 for ease of illustrating other features, including UV sterilizing lighting, may also be disposed in the cabinet 3204.

[0180] While in the above-described embodiment the reheat coils 3244LC, 3244UC are arranged in parallel, it is contemplated that in other embodiments the upper canopy air supply reheat coil and the lower canopy air supply reheat coil may be arranged in series. In such anembodiment, one of the upper canopy air supply reheat coil and the lower canopy air supply reheat coil would receive cooled, dehumidified air from the cooling coil and reheat that air to a first temperature, and a portion thereof would be directed to the respective (upper or lower) canopy air supply plenum. Another portion of that reheated air would then be supplied to the other one of the upper canopy air supply reheat coil and the lower canopy air supply reheat coil, which would further heat the reheated air to become further heated air to be supplied to the other (upper or lower) canopy air supply plenum.

[0181] Embodiments using a single reheat coil, or two parallel or series reheat coils, may be combined, for example, with a bulk air treatment system, analogously to the arrangement shown in Figure 1. The bulk air could be conditioned to a specific temperature and humidity, and then reheated to one or two different temperatures by the reheat coil(s).

[0182] As with the controlled environmental stratification system 2600 shown in Figures 26 to 28, the illustrative controlled environmental stratification system 3000 shown in Figure 30 is also provided with agricultural lighting. This includes a lower canopy agricultural lighting system, an intermediate agricultural lighting system and an upper canopy agricultural lighting system. In the illustrated embodiment the lower canopy agricultural lighting system, the intermediate agricultural lighting system and the upper canopy agricultural lighting system each comprise a respective plurality of spaced-apart lighting bars 3012, 3014, 3038, such as for example MetaRail™ or HyperRail™ lighting bars, suspended from the upper air return duct 3034. In Figure 30, only the lower canopy lighting bars 3012 and the upper canopy lighting bars 3038 are shown for clarity of illustration as the intermediate canopy lighting bars 3014 would obscure aspects of Figure 30; Figures 33 A through 33C show all three groups of lighting bars 3012, 3014, 3038.

[0183] The lower canopy lighting bars 3012 forming the lower canopy agricultural lighting system are positioned between the lower height and the upper height, that is, between the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900 supporting the lower plants 1906 and the upper canopy airflow outlets formed by the canopy airflow nozzles 1272. The intermediate canopy lighting bars 3014 forming the intermediate agricultural lighting system are positioned between the lower height and the upper height but slightly higher, above the lower canopy airflow outlets formed by the outlet apertures 2904 in the sides 2902 of the plant carrier plenums 2900 supporting the intermediate plants 1916 and below the upper canopy airflow outlets formed by the canopy airflow nozzles 1272.The upper canopy lighting bars 3038 forming the upper canopy agricultural lighting system are positioned above the upper height, that is, above the upper canopy airflow outlets formed by the canopy airflow nozzles 1272. Thus, lower canopy lighting bars 3012 provide primary lighting for the lower plants 1906, the intermediate canopy lighting bars 3014 provide primary lighting for the intermediate plants 1916 and the upper canopy lighting bars 3038 provide primary lighting for the upper plants 1902.

[0184] Figure 30A shows how a plurality of the controlled environmental stratification systems 3000 may be arranged in vertical tiers. While only two tiers are shown, there may be three or more tiers.

[0185] Reference is now made to Figures 33A through 34C, which show the various airflows which create the upper canopy environment 1910 (see Figure 19) surrounding the upper plant canopy 1904 and the lower canopy environment 1912 (see Figure 19) surrounding both the lower plant canopy 1908 and the intermediate plant canopy 1918. Figures 33A through 33C are side cross-sectional views and Figures 34A through 34C are end cross-sectional views. Figures 33A and 34A show operation of components associated with the lower plants 1906 and the intermediate plants 1916 in isolation, Figures 33B and 34B show operation of components associated with the upper plants 1902 in isolation, and Figure 33C and 34C show both sets of components.

[0186] A first flow of treated (e.g. cooled and dehumidified and then reheated) air 3392 enters the upper canopy air supply plenum 3050 from the upper canopy air supply reheat coil 3244UC under urging from the upper canopy air supply fan 3218UC. From the upper canopy air supply plenum 3050, the treated air 3392 is collected by the canopy air supply regulators 2000 and fed through the extension tubes 2340 to the nozzles 1272. The canopy air supply regulators 2000 depend downwardly into the interior volume of the air supply plenum 2650, compensate for chaotic turbulent air and dead air pockets, and compensate for pressure drop along the length of the upper canopy air supply plenum 3050. To some extent, the canopy air supply regulators 2000 may also generate turbulence, which disrupts laminar flow within the upper canopy air supply plenum 3050. Adjusting the orientation of the canopy air supply regulators 2000 within the upper canopy air supply plenum 3050, and adjusting the position and orientation of the air concentrator scoop 2008 within the hollow tube 2002, can control the turbulence and obtain a desired airflow through the extension tubes 2340 into the nozzles 1272. In addition, to some extent adjustment of the airflow through the nozzles 1272 can also compensate for pressuredrop along the length of the upper canopy air supply plenum 3050. Conventional ducts without canopy air supply regulators and without adjustable nozzles, for example soft inflatable “sockducts”, would not be able to get the air to move far enough into the canopy and cannot adjust for lengthwise variations in flow and velocity; the velocity at exit would drop precipitously after the air has travelled only a very short distance. Optionally, the planters 2640 may include inlets connected in fluid communication with the upper canopy air supply plenum 3050, for example by way of the canopy air supply regulators 2000, to provide airflow through the planters 2640 for root zone cooling.

[0187] As the treated air 3392 flows through the extension tubes 2340 to the nozzles 1272 at a positive air pressure, it escapes through the nozzles 1272 and moves toward the upper plant canopies 1904 of the upper plants 1902 disposed in the planters 2640. This air is drawn upward toward and into the inlet apertures 3036 of the upper air return duct 3034 by the negative air pressure therein, and returned to the cabinet 3204. Accordingly, positive air pressure is applied on the ventral side of the upper plant canopies 1904, with negative air pressure applied on the dorsal side of the upper plant canopies 1904. The air is thus drawn from the ventral side of the upper plant canopies 1904 through the upper plant canopies 1904 and past the dorsal side thereof to withdraw heat from the upper canopy lighting bars 3038 and also humidity from plant respiration. Because the upper canopy airflow outlets are formed by adjustable canopy airflow nozzles 1272, airflow through the upper canopy airflow outlets is adjustable. By adjusting the flow of treated air through the canopy airflow nozzles 1272 that form the upper canopy airflow outlets, and by adjusting the amount of cooling by the cooling coil 3242 and the amount of reheating by the upper canopy air supply reheat coil 3244UC, the temperature and / or humidity and / or VPD of the air surrounding the upper plant canopies 1904 can be controlled. The air that is drawn into the upper air return duct 3034 carries the heat and humidity away from the upper plant canopies 1904 and is returned, as untreated air 3394, to the cabinet 3204 for treatment.

[0188] Additionally, as shown in Figures 34B and 34C, the air curtain nozzles 1270 can be coupled in fluid communication with the upper canopy air supply plenum 3050 via the canopy air supply regulators 2000, and arranged along the outer edge of the upper canopy air supply plenum 3050 along the length thereof. The air curtain nozzles 1270 generate an air curtain 3402 extending along the outer edge of the upper canopy air supply plenum 3050; the air curtain 3402 serves as a shield to inhibit air spillover from the canopy airflow nozzles 1272 forming the upper canopy airflow outlets toward the outlet apertures 2904 in the plant carrier plenums 2900 that form the lower canopy airflow outlets. In addition, the air curtain 3402 alsoinhibits airstreams from the canopy airflow nozzles 1272 forming the upper canopy airflow outlets from shooting beyond the footprint of the controlled environmental stratification system 3000, for example into aisles between a plurality of such systems arranged in a growing operation. The air from the air curtain 3402 is also drawn into the upper air return duct 3034. In other embodiments, the shield may take the form of a physical deflector, such as a plate or a sheet, or may be omitted. Thus, while the air curtain nozzles 1270 and air curtain 3402 are preferred, they may be absent in some embodiments.

[0189] A second flow of treated (e.g. cooled and dehumidified and then reheated) air 3396 enters the lower canopy air supply plenum 3054 from the lower canopy air supply reheat coil 3244LC under urging from the lower canopy air supply fan 3218LC. From the lower canopy air supply plenum 3054, the treated air 3392 is collected by the canopy air supply regulators 2000 and fed into the plant carrier plenums 2900. The canopy air supply regulators 2000 also provide turbulence to maintain consistent airflow along the entire length of the lower canopy air supply plenum 3054. The second flow of treated air 3396 enters the plant carrier plenums 2900 at a positive air pressure, and escapes through the outlet apertures 2904 and moves toward the lower plant canopies 1908 of the lower plants 1906 and toward the intermediate plant canopies 1918 of the intermediate plants 1916, both of which are disposed in respective channels 2906 of the plant carrier plenums 2900. Much of this air is drawn laterally into the inlet apertures 3060 of the lower air return duct 3058; some of the air is drawn upward toward and into the inlet apertures 3036 of the upper air return duct 3034 by the negative air pressure therein. Thus, the upper air return duct 3034 is configured to withdraw air supplied by both the upper canopy airflow outlets and the lower canopy airflow outlets; in alternate embodiments, the lower air return duct may be omitted and the air from both the upper canopy airflow outlets and the lower canopy airflow outlets may be withdrawn entirely by the upper air return duct. In the further alternative, the lower air return duct may be disposed below the intermediate plant canopy so that the air emerging from the intermediate plant canopy is drawn into the upper air return duct. It is preferred, however, to include the lower air return duct 3058 and have it withdraw most of the air from the lower plant canopies 1908 and the intermediate plant canopies 1918 as this provides for greater temperature control. The air emerging from the dorsal sides of the lower plant canopies 1908 and the intermediate plant canopies 1918 will have been warmed by the lower canopy lighting bars 3012 and intermediate canopy lighting bars 3014 and humidified by respiration of the lower plants 1906 and intermediate plants 1916. By withdrawing much of this warmed and humidified air into the lower air return duct 3058, the contribution of the heatand humidity to the environment surrounding the upper plant canopies 1904 can be reduced. This, in combination with two different reheat coils 3244UC, 3244LC allows for the environment surrounding the upper plant canopies 1904 to be either be warmer and / or less humid, or cooler and / or more humid, than the environment surrounding the lower plant canopies 1908 and the intermediate plant canopies 1918. As noted above, the airflow through the canopy airflow nozzles 1272 forming the upper canopy airflow outlets can be modulated by adjusting the canopy airflow nozzles 1272 in conjunction with adjustment of the associated canopy air supply regulators 2000.

[0190] As can be seen in Figures 33A, 33C, 34A and 34C, positive air pressure is applied on the ventral sides of the lower plant canopies 1908 and intermediate plant canopies 1918 and negative air pressure is applied on the dorsal sides of the lower plant canopies 1908 and intermediate plant canopies 1918. Air is drawn from the ventral sides of the lower plant canopies 1908 and intermediate plant canopies 1918 across the lower plant canopies 1908 and intermediate plant canopies 1918, respectively, and past the respective dorsal sides thereof to withdraw heat from the lower canopy lighting bars 3012 and intermediate canopy lighting bars 3014 and further withdraw humidity from plant respiration. The airflow through the outlet apertures 2904 of the plant carrier plenums 2900 can be controlled by adjusting the associated canopy air supply regulators 2000, enabling control of the temperature and / or humidity and / or VPD of the air surrounding the lower plant canopies 1908 and intermediate plant canopies 1918. In addition, the airflow through the plant carrier plenums 2900 may provide root zone cooling for the lower plants 1906 and intermediate plants 1916; optionally outlets may be disposed within the channels 2906 to increase this effect.

[0191] The controlled environmental stratification system 3000 shown in Figures 30 to 34C may also be provided with an irrigation / fertigation system and / or drainage arrangement similar to that described above.

[0192] In some embodiments, instead of using an integrated HVAC system, a modified version of the controlled environmental stratification system 3000 shown in Figures 30 to 34C may use cooled treated air supplied in bulk from an external source, such as an HVAC system supplying air to the room in which the controlled environmental stratification system is located. Instead of a single cabinet containing an integrated HVAC system, the system may have a supply cabinet at one end and an exhaust cabinet at the other end. The intake cabinet is connected in fluid communication with the lower canopy air supply plenum and the uppercanopy air supply plenum and the exhaust cabinet is connected in fluid communication with the lower air return duct and the upper air return duct. The supply cabinet includes at least one supply fan that draws the bulk treated air into the supply cabinet and forces the air into the lower canopy air supply plenum and the upper canopy air supply plenum, and includes at least one reheat coil to increase the temperature and / or humidity of the air entering the lower canopy air supply plenum and / or the upper canopy air supply plenum. There may be only a single reheat coil, or there may be a reheat coil for each of the lower canopy air supply plenum and the upper canopy air supply plenum. There may be only a single supply fan, or there may be a supply fan for each of the lower canopy air supply plenum and the upper canopy air supply plenum. The exhaust cabinet includes at least one exhaust fan that draws air out of the lower air return duct and the upper air return duct and exhausts it to ambient. There may be only a single exhaust fan, or there may be an exhaust fan for each of the lower air return duct and the upper air return duct. This arrangement allows for the supply fan(s) to be run at different speed(s) from the exhaust fan(s), providing for more nuanced control. This embodiment may be seen as a combination of the controlled environmental stratification system 3000 shown in Figures 30 to 34C with the HVAC system shown in Figure 1.

[0193] One of ordinary skill in the art, now informed by the present disclosure, will appreciate that an arrangement of the type shown in Figure 19A, in which the intermediate canopy environment 1920 has an intermediate canopy air temperature and / or humidity and / or VPD that is different from the lower canopy environment 1912 and the upper canopy environment 1910 may be achieved by suitable modification of the arrangement shown in Figures 30 through 34C. For example, the height of the lower air return duct may be reduced, and an intermediate canopy air supply plenum and intermediate canopy air return duct, similar in construction to the lower canopy air supply plenum 3054 and lower canopy air return duct 3058, may be provided at a height above lower canopy supply plenum and lower air return duct. In such an arrangement, the cabinet may be provided with an intermediate reheat coil and intermediate canopy air supply fan in fluid communication with the intermediate canopy air supply plenum, with the intermediate canopy air return duct feeding into the cabinet.

[0194] As shown in Figures 35 A and 35B, a structure in which a canopy air supply plenum 3554 and an air return duct 3558 are disposed within a common housing 3502 (as shown in Figure 31) can be utilized to enable a containerized embodiment 3500 of a vertically tiered controlled environmental stratification system for intercropped plant cultivation. A plurality of instances of the commonly housed canopy air supply plenum 3554 and air return duct 3558 arearranged in tiers within the interior volume 3503 of a standardized intermodal container / ISO container 3501, with a plurality of fans 3518 pushing treated air from a common modular HVAC cabinet 3504 (e.g. as shown in Figure 12 or 18) into the canopy air supply plenum 3554 and pulling air into the air return duct 3558. A plurality of plant carrier plenums 2900 as shown in Figures 29A and 29B are coupled in fluid communication with the canopy air supply plenums 3554 via canopy air supply regulators 2000, analogously to the arrangement shown in Figures 30 to 34C. The plant carrier plenums 2900 carry plants 3506 having a plant canopy 3508, and canopy lighting bars 3512 provide agricultural lighting for the plants 3506. Treated air from the canopy air supply plenum 3554 is directed by the canopy air supply regulators 2000 into the plant carrier plenums 2900, flows through the outlet apertures 2904 and then flows from the ventral side of the plant canopies 3508 through to the dorsal side, and then through apertures 3560 into the air return duct 3558, carrying heat and humidity away from the plant canopies 3508.

[0195] Although shown as externally mounted outside of the container 3501, in other embodiments the cabinet containing the modular HVAC system may be disposed within the container. An irrigation or fertigation system may also be provided. Optionally, instead of the air return duct 3558 being disposed within the common housing 3502, the air return duct may be a separate duct that extends across the plant carrier plenums 2900 and / or an additional air return duct may be provided.

[0196] The controlled environmental stratification system 2600 shown in Figures 26 to 28, and / or the controlled environmental stratification system 3000 shown in Figures 30 to 34C, may also be adapted for containerization.

[0197] Configurations in which modified versions of the plant carrier plenums can receive canopy air supply regulators 2000 coupled to canopy airflow nozzles 1272 (for example, in between plants in the channel) are also contemplated.

[0198] It is also contemplated that aspects of the presently described systems and methods can be employed in aquaponics applications as well.

[0199] While illustrative embodiments have shown a vertical arrangement in which the airflow from the ventral side of the plant canopy toward the dorsal side of the plant canopy is substantially vertical relative to the earth, the present disclosure is not so limited, and also contemplates, for example, arrangements in which the airflow from the ventral side of the plant canopy toward the dorsal side of the plant canopy is substantially horizontal relative to theearth. For example, it is contemplated that the principles applied herein may be applied to produce substantially horizontal airflow from the ventral side of the plant canopy toward the dorsal side of the plant canopy in a system such as the AirBox™ Horticultural Production Platform offered by the aforesaid AgricUltra Advancements Inc. and described in PCT International Patent Application No. PCT / CA2019 / 050322 filed on March 15, 2019, the teachings of which are hereby incorporated by reference.

[0200] Certain illustrative embodiments have been described by way of example. It will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the claims.

Claims

CLAIMSWhat is claimed is:

1. A method for plant cultivation, the method comprising: providing at least one upper plant of a first plant type and having an upper plant canopy; providing at least one lower plant of a second plant type and having a lower plant canopy; the first plant type being different from the second plant type; wherein the lower plant canopy is disposed below the upper plant canopy with the upper plant canopy at least partially overlapping the lower plant canopy; maintaining an upper canopy environment surrounding the upper plant canopy, the upper canopy environment having an upper canopy air temperature; maintaining a lower canopy environment surrounding the lower plant canopy, the lower canopy environment having a lower canopy air temperature; wherein the upper canopy air temperature is different from the lower canopy air temperature; wherein the first plant type is better suited to the upper canopy environment than to the lower canopy environment; and wherein the second plant type is better suited to the lower canopy environment than to the upper canopy environment.2 The method of claim 1, wherein the upper canopy environment has a different humidity than the lower canopy environment.3 The method of claim 1, wherein there is a temperature gradient between the upper canopy environment and the lower canopy environment.

4. The method of claim 1, further comprising shielding the lower canopy environment against air spillover from the upper canopy environment.

5. The method of claim 1, further comprising: providing at least one intermediate plant of the second plant type and having an intermediate plant canopy; wherein the intermediate plant canopy is disposed above the lower plant canopy and below the upper plant canopy with the upper plant canopy at least partially overlapping the intermediate plant canopy; and maintaining the lower canopy environment surrounding the intermediate plant canopy.6 The method of claim 1, further comprising: providing at least one intermediate plant of a third plant type and having an intermediate plant canopy; wherein the third plant type is different from both the first plant type and the second plant type; wherein the intermediate plant canopy is disposed above the lower plant canopy and below the upper plant canopy with the upper plant canopy at least partially overlapping the intermediate plant canopy; and maintaining an intermediate canopy environment surrounding the intermediate plant canopy, the intermediate canopy environment having an intermediate canopy air temperature; wherein the intermediate canopy air temperature is different from both the upper canopy air temperature and the lower canopy air temperature.7 The method of claim 1, wherein:the lower canopy environment is cooler than the upper canopy environment; and a root zone of the at least one upper plant is disposed within the lower canopy environment.

8. A controlled environmental stratification system for intercropped plant cultivation, comprising: at least one air supply plenum configured to supply positive air pressure to: a plurality of spaced apart upper canopy airflow outlets; and a plurality of spaced apart lower canopy airflow outlets; the plurality of upper canopy airflow outlets arranged at an upper height; the plurality of lower canopy airflow outlets arranged at a lower height that is below the upper height; and at least one upper air return duct positioned above the upper height and configured to apply negative air pressure above the upper canopy airflow outlets.9 The controlled environmental stratification system of claim 8, wherein the at least one air supply plenum comprises: at least one upper canopy air supply plenum configured to supply a first positive air pressure to the upper canopy airflow outlets; and at least one lower canopy air supply plenum configured to supply a second positive air pressure to the lower canopy airflow outlets.10 The controlled environmental stratification system of claim 8, wherein the at least one air supply plenum is at least one common air supply plenum supplying the positive air pressure to both the upper canopy airflow outlets and lower canopy airflow outlets.

11. The controlled environmental stratification system of claim 8, wherein the at least one upper air return duct is configured to withdraw air supplied by both the upper canopy airflow outlets and the lower canopy airflow outlets.

12. The controlled environmental stratification system of claim 8, further comprising at least one lower air return duct positioned between the lower height and the upper height and configured to apply negative air pressure above the lower canopy airflow outlets and below the upper canopy airflow outlets.

13. The controlled environmental stratification system of claim 8, further comprising a lower canopy agricultural lighting system positioned between the lower height and the upper height.

14. The controlled environmental stratification system of claim 8, further comprising an upper canopy agricultural lighting system positioned above the upper height.

15. The controlled environmental stratification system of claim 8, further comprising: a lower canopy agricultural lighting system positioned between the lower height and the upper height; and an upper canopy agricultural lighting system positioned above the upper height.

16. The controlled environmental stratification system of claim 8, further comprising at least one shield configured to inhibit air spillover from the upper canopy airflow outlets toward the lower canopy airflow outlets.

17. The controlled environmental stratification system of claim 16, wherein the at least one shield is one of an air curtain or a deflector.

18. The controlled environmental stratification system of claim 8, wherein the upper canopy airflow outlets are adjustable nozzles whereby airflow through the upper canopy airflow outlets is adjustable.

19. The controlled environmental stratification system of claim 8, wherein the upper height is adjustable.

20. A plant cultivation system comprising a plurality of controlled environmental stratification systems according to claim 8, arranged in vertical tiers.

21. The controlled environmental stratification system of claim 9, wherein the at least one upper canopy air supply plenum extends substantially in parallel with the at least one lower canopy air supply plenum.

22. The controlled environmental stratification system of claim 21, wherein: the at least one lower canopy air supply plenum is in fluid communication with a plurality of spaced-apart plant carrier plenums in which the lower canopy airflow outlets are formed; the plant carrier plenums extend substantially perpendicular to and are disposed atop the at least one upper canopy air supply plenum.

23. The controlled environmental stratification system of claim 10, wherein:the at least one common air supply plenum is in fluid communication with a plurality of spacedapart plant carrier plenums in which the lower canopy airflow outlets are formed; the plant carrier plenums extend substantially perpendicular to and are disposed atop the at least one common air supply plenum.

24. The controlled environmental stratification system of claim 22 or claim 23, wherein the plant carrier plenums include channels formed therein and adapted to receive plant containers, and wherein the lower canopy airflow outlets extend alongside the channels.

25. The controlled environmental stratification system of claim 11, wherein: the controlled environmental stratification system comprises a modular recirculating air distribution and heat extraction system comprising an HVAC system; the HVAC system is an integrated HVAC system comprising: an air circulation mechanism; at least one cooling coil adapted to remove moisture; at least one first reheating coil downstream of the at least one cooling coil; and at least one second reheating coil downstream of the at least one cooling coil; all positioned within a cabinet of the modular recirculating air distribution and heat extraction system; wherein: the air circulation mechanism is adapted to pull untreated air through the at least one upper air return duct to apply the negative air pressure above the upper canopy airflow outlets; and the air circulation mechanism is further adapted to push treated air through the at least one upper canopy air supply plenum to supply the first positive air pressure to the upper canopyairflow and through the at least one lower canopy air supply plenum to supply the second positive air pressure to the lower canopy airflow outlets.

26. The controlled environmental stratification system of claim 25, wherein: the at least one first reheating coil and the at least one second reheating coil are arranged in parallel, wherein: the at least one first reheating coil receives cooled air from the at least one cooling coil and reheats the cooled air to a first temperature to become first reheated air and supplies the first reheated air to one of the at least one upper canopy air supply plenum and the at least one lower canopy air supply plenum; and the at least one second reheating coil receives the cooled air from the at least one cooling coil and reheats the cooled air to a second temperature to become second reheated air and supplies the second reheated air to the other of the at least one upper canopy air supply plenum and the at least one lower canopy air supply plenum; wherein the first temperature and the second temperature are different from one another.

27. The controlled environmental stratification system of claim 25, wherein: the at least one cooling coil, the at least one first reheating coil and the at least one second reheating coil have respective modulating valves to regulate fluid flow therethrough; and a control system independently regulates fluid flow through each of the at least one cooling coil, the at least one first reheating coil and the at least one second reheating coil.

28. The controlled environmental stratification system of claim 27, wherein the control system comprises a proportional-integral-derivative (PID) controller.

29. A canopy air supply regulator, comprising: a hollow tube having an inlet end and an outlet end; and an air concentrator scoop carried by the hollow tube; wherein the inlet end of the tube and the air concentrator scoop cooperate to define contours of an inlet aperture of the regulator; and the air concentrator scoop is selectively displaceable relative to the hollow tube to adjust the contours of the inlet aperture.

30. The canopy air supply regulator of claim 29 wherein the inlet end is truncated obliquely relative to an axial direction of the tube.

31. The canopy air supply regulator of claim 29, wherein the air concentrator scoop is selectively axially extendible and retractable along the hollow tube to vary an extent by which the air concentrator scoop protrudes beyond the inlet end and thereby adjust the contours of the inlet aperture.

32. The air canopy supply regulator of claim 31, wherein the air concentrator scoop is selectively axially rotatable relative to the hollow tube to further adjust the contours of the inlet aperture.

33. The air canopy supply regulator of claim 32, wherein the air concentrator scoop is nested within the hollow tube.

34. The air canopy supply nozzle of claim 32, wherein: the air concentrator scoop comprises a resilient sheet biased into a planar configuration; the resilient sheet is rolled into a scoop-ended inner tube that is received within the hollow tube wherein the bias into the planar configuration retains the scoop -ended inner tube in slidable frictional engagement with an inner surface of the hollow tube.

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