The process of lowering the temperature in a greenhouse

Abstract

The present invention relates to a greenhouse (1) and a process for reducing or maintaining the temperature in a growing space (8) provided in the greenhouse (1), (a) collecting ambient air, air from the growing space (8) and / or a mixture of ambient air and air from the growing space (8) to obtain a supply air; (b) reducing the temperature of the water source to a lower temperature by indirect heat exchange against a cooling medium to obtain chilled water; (c) directly contacting a portion of the supply air with cold water, where the temperature of the supply air is lower than the dew point of the supply air, to cool the supply air, thereby obtaining cooled air as conditioned air and used cold water, and discharging the conditioned air into the cultivation space (8).

Description

[Technical field]

[0001] The present invention relates to a process for reducing or maintaining the temperature of a growing space provided in a greenhouse. [Background technology]

[0002] Such a process is described in WO 2008 / 002686, which describes a greenhouse with a space in the end gable wall in which ambient air and / or greenhouse recirculated air is collected and distributed to the growing compartments via a number of parallel ventilation tubes. According to this publication, the interior of the greenhouse can be cooled by drawing in ambient air through a pad cooling system located at the ambient air inlet in the gable end wall and distributing this air through the ventilation tubes.

[0003] Japanese Patent Publication No. 20156133 describes a greenhouse having a space in an end gable wall where ambient air and / or greenhouse recirculated air is collected and distributed to the growing sections via multiple parallel ventilation pipes. The ambient air is optionally mixed with the greenhouse recirculated air and passed through a water pad before being distributed to the growing sections. If desired, the greenhouse recirculated air may be mixed with the air that has passed through the water pad before being distributed to the growing sections.

[0004] Controlling the environment in greenhouses by using ambient air and greenhouse recirculated air has been known for many years and is described, for example, in U.S. Patent No. 3,404,618, published in 1968. This publication describes ventilation tubes that distribute ambient air, recirculate greenhouse air, or a combination to the growing areas of the greenhouse. Cooling can be achieved by drawing air through water-cooled pads.

[0005] WO 2017 / 176114 describes a greenhouse in which the ambient air is cooled by first contacting the air with liquid water to obtain a cooled and saturated air flow in an evaporative pad. This air flow is subsequently contacted with an aqueous solution of 1,2-propanediol to dry the air. The dry air is contacted with water to obtain cooled air, which is then distributed to the growing compartments via ventilation pipes.

[0006] A drawback of the prior art processes is that the cooling provided by the water pads may be insufficient, especially in conditions of high relative humidity of the ambient air. The object of the present invention is to provide a process and a system for reducing or maintaining the temperature in a growing space provided in a greenhouse. More specifically, the process should be able to operate in conditions of high relative humidity of the ambient air. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2008 / 002686 [Patent Document 2] JP 2015-6133 A [Patent Document 3] U.S. Pat. No. 3,404,618 [Patent Document 4] International Publication No. 2017 / 176114 Summary of the Invention

[0008] This is accomplished by the following process: A process for reducing or maintaining the temperature within a growing space provided within a greenhouse includes: (a) collecting ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space to obtain a supply air; (b) reducing the temperature of the water source to a lower temperature by indirect heat exchange with a cooling medium to obtain chilled water; (c) directly contacting a portion of the supply air with cold water, the temperature of the cold water being lower than the dew point of the supply air to cool the supply air, thereby obtaining cooled air as conditioned air and used cold water, and discharging the conditioned air into the cultivation space.

[0009] The applicants have found that such a process allows the temperature in the growing space to be reduced or kept at a desired low temperature even when the relative humidity of the surrounding air is high. For example, when the surrounding air having a high relative humidity is cooled according to this process, the water present in the air condenses. This water may be advantageously used as irrigation water. Since the cooling medium does not come into direct contact with the water in contact with the air, no contamination of the air by the cooling medium can occur. This allows the use of the most optimal cooling medium in terms of energy efficiency. Further advantages will be explained when describing the preferred embodiment below.

[0010] The supply air in the process can be ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space, and suitably ambient air or a mixture of ambient air and air from the growing space. The ambient air can have a temperature between 18°C ​​and 40°C and a relative humidity of more than 50%, suitably between 50% and 80%. It is at these temperatures and relative humidity characteristics of the ambient air that the advantages of the present process are most evident. The wet bulb temperature of the ambient air is suitably equal to or greater than the dry bulb temperature of the air from the growing space.

[0011] The water source in step (b) may be, for example, drinking water, rainwater, and / or non-conventional resources such as industrial process wastewater, supplied from surface and / or subsurface reservoirs. Preferably, the cold water used to cool the water source is reused as the water source in step (b). In this way, the use of fresh water sources is limited. To avoid salt accumulation in such a recirculating water stream, a part of the water is discharged from this recirculating water stream. The amount of water discharged may be constituted by adding fresh water to the recirculating water stream, which may be, for example, any of the aforementioned sources. A part of the water present in the supply air condenses in step (c) and becomes part of the used cold water. This amount of water may be sufficient to compensate for the amount of water discharged. In such a situation, it is not necessary or very little to add such fresh water to the recirculating water stream. Preferably, at least the amount of water condensed from the supply air is used as irrigation water in the growing space.

[0012] The obtained irrigation water may be supplemented by other freshwater sources before being supplied to the plants present in the growing area. This water may be treated before being supplied to the plants, for example to reduce mineral ions, bacteria, biofilms, yeast or other microorganisms that may be present in the water. Examples of suitable treatments are UV treatment and / or heat treatment. Other treatments that may be used alone or in combination with one of the above-mentioned treatments are, for example, the addition or in situ generation of ozone, chlorine, hypochlorite and hydrogen peroxide, membrane filtration, electrodialysis, or ultrasonic noise treatment, etc. One example of a suitable treatment is the addition of thermal and non-thermal plasma activated water with nitrite and hydrogen peroxide compounds as described in US Patent Application Publication No. 2018 / 0327283. Such a process can reduce undesirable bacteria, biofilms, yeast or other microorganisms while also providing nitrogen species that can act as fertilizers.

[0013] In this step (b), the cold water is obtained by lowering the temperature of a water source by indirect heat exchange against a cooling medium. Such a cooling medium may be an evaporating liquid, such as evaporating ammonia, or may be a liquid or gas having a temperature lower than that of the cold water. The cooling medium is preferably in a closed circuit where it is circulated and reused as a cooling medium. Suitable cooling media are ammonia and refrigerant gases.

[0014] The indirect heat exchange in step (b) can be carried out in known heat exchange devices, such as, for example, a shell-and-tube heat exchanger or a plate heat exchanger.

[0015] Step (b) is preferably carried out with the aid of a heat pump. The heat pump suitably transfers thermal energy from a first heat carrier fluid, preferably water, using a refrigeration cycle to a second heat carrier fluid, preferably water, acting as a heat sink, to obtain a cooling medium and a heated second heat carrier fluid for use in step (b). The first heat carrier fluid acting as a heat sink may be air when the heat exchange takes place in so-called dry coolers. These dry coolers comprise a fan that directs air along the heat exchange surface. This is energy intensive and dry coolers require a large construction area. For this reason, it is preferred to use a fluid, preferably water, as a heat sink, so that a heated second heat carrier fluid, preferably heated water, is prepared. This heat exchange can be carried out with much smaller equipment and does not require the same amount of energy as the aforementioned dry coolers.

[0016] The problem is that a heated second heat carrier fluid, for example heated water, is obtained, which needs to be drained. The applicants have found that a heated second heat carrier fluid, for example heated water, can be used to obtain a source of heated water by indirect heat exchange. The source of heated water is used to cool the temperature of the supply air during the day by bringing the supply air into direct contact with this source of heated water.

[0017] Therefore, preferably, step (c) is performed during part or all of the night, and in step (c2) during part or all of the day, a portion of the supply air is contacted with a source of heated water, such that the supply air is cooled to a temperature close to the wet-bulb temperature by evaporation of a portion of the source of heated water, thereby obtaining cooled air as conditioned air, which is discharged into the cultivation space, and in step (b2) a source of heated water is obtained by indirect heat exchange with a heated second heat carrier fluid.

[0018] The direct contact in step (c2) suitably takes place within a vertically extending wetting screen, with a source of heated water flowing downward and feed air passing laterally through the wetting screen.More preferably, the same wetting screen is used in steps (c1) and (c2).

[0019] The contacting of the supply air with chilled water as in step (c) occurs during part or all of the night, and the contacting of the supply air with the source of heated water occurs during part or all of the day. This method is particularly advantageous in the spring, summer and fall, when both nighttime and daytime cooling may be required. For this purpose, nighttime is defined as between 6 p.m. and 6 a.m., and daytime is defined as between 6 a.m. and 6 p.m. local time.

[0020] The present invention therefore also relates to a process for reducing or maintaining the temperature in a growing space provided in a greenhouse, comprising: (a) collecting ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space to obtain a supply air; (b) obtaining a cooling medium and a heated second heat carrier fluid by a heat pump, the heat pump transferring thermal energy from a first heat carrier fluid (preferably water) to a second heat carrier fluid (preferably water) acting as a heat sink using a refrigeration cycle to obtain a cooling medium and a heated second heat carrier fluid; (b1) obtaining chilled water by reducing a temperature of a first water source to a lower temperature by indirect heat exchange with a cooling medium; (b2) obtaining a source of heated water by indirect heat exchange with a heated second heat carrier fluid; (c1) during part or all of the night, directly contacting a portion of the supply air with the cold water obtained in step (b1), where the temperature of the cold water is lower than the dew point of the supply air, and the supply air is cooled, thereby obtaining cooled air as conditioned air and used cold water, and discharging the conditioned air into the cultivation space; (c2) during part or all of the daytime, directly contacting a portion of the supply air with the source of heated water obtained in step (b2), wherein the supply air is cooled to a temperature close to the wet-bulb temperature by evaporation of a portion of the source of heated water, thereby obtaining cooled air as conditioned air, and discharging the conditioned air into the cultivation space.

[0021] The temperature of the chilled water is suitably more than 5°C below the dew point of the supply air, preferably more than 10°C below the dew point of the supply air. Preferably the temperature of the chilled water is between 5 and 10°C.

[0022] The direct contact in step (c) is suitably carried out in a vertically extending wetting screen, with the cold water flowing downward and the supply air passing laterally through the wetting screen. These wetting screens are also known as water pads or evaporation pads. The wetting screen is suitably a vertically arranged wetting screen, with the cold water flowing from its top to its bottom and the supply air passing through the screen in a substantially horizontal flow direction. The supply air is in direct contact with the cold water in the pad. As the temperature of the cold water is lower than the dew point of the supply air, water condenses from the supply air and becomes part of the used cold water. Examples of such vertically extending wetting screens are described in WO 2004 / 068051, EP 1 659 357 and US 5 966 ​​953.

[0023] The humidity of the cooling air is increased to a relative humidity of up to 100%, which may be too high for the cooling air to be discharged directly into the growing space as conditioned air. The humidity of the conditioned air may be appropriately reduced by diluting the cooling air with air that is not in contact with the cold water of step (c). More preferably, in a further step (d), the ambient air, the air from the growing space, and / or a mixture of the ambient air and the air from the growing space that is not in contact with the cold water of step (c) is mixed with the cooling air to obtain conditioned air. Even more preferably, the ambient air, the air from the growing space, and / or a mixture of the ambient air and the air from the growing space that is not in contact with the cold water of step (c) is increased in temperature before being mixed with the cooling air. In this way, the relative humidity of the obtained conditioned air may be further reduced.

[0024] The above process may be carried out in any greenhouse where the temperature is reduced before the ambient air is introduced into the growing compartment of the greenhouse. More suitably, the process is carried out in a semi-closed greenhouse, for example as described in the aforementioned International Publication No. 2008 / 002686, Japanese Patent Publication No. 20156133, and International Publication No. 2017 / 176114.

[0025] If the greenhouse is equipped with a means for preparing cold water as described above, in particular a source of heated water, it may be used to dehumidify the air in the cultivation areas of the greenhouse. This may be carried out by the following process: A process for dehumidifying the air present in the cultivation spaces provided in the greenhouse, comprising: (b) obtaining a cooling medium and a heated second heat carrier fluid by a heat pump, the heat pump transferring thermal energy from a first heat carrier fluid, preferably water, to a second heat carrier fluid, preferably water, acting as a heat sink, using a cooling cycle, to obtain a cooling medium and a heated second heat carrier fluid; (b1) obtaining chilled water by reducing a temperature of a first water source to a lower temperature by indirect heat exchange with a cooling medium; (cc) directly contacting a portion of the air from the growing area with the cold water obtained in step (b1) in a vertically extending wetting screen, wherein the cold water flows downward through the wetting screen and the air from the growing area passes laterally through the wetting screen, the temperature of the cold water being lower than the dew point of the air from the growing area, thereby obtaining dehumidified air, and discharging the dehumidified air into the growing area.

[0026] The above process is advantageous because less air must be evacuated from the greenhouse to reduce the absolute humidity, therefore less heat and carbon dioxide is lost, and as a result less carbon dioxide needs to be added to the greenhouse.

[0027] The heated second heat carrier fluid as obtained in the air dehumidification process described above is suitably either directly or via another heat carrier used to heat the air, the irrigation water and / or any plants in the growing plot.

[0028] The dehumidified air obtained in step (cc) may be heated before or after discharging it into the growing area, this heating may be carried out by indirect heat exchange against a heated second heat carrier fluid.

[0029] The greenhouse according to the invention described herein is preferably used to carry out the process according to the invention in summer and the above-mentioned air dehumidification process in spring, autumn and / or winter, thereby allowing efficient utilization of the greenhouse in different seasons. [Brief description of the drawings]

[0030] [Figure 1] Shown is a greenhouse with a gable roof (2), a floor (3), two end walls (4) and two side walls (5). [Diagram 2] A variation of the greenhouse of Figure 1 is shown in which there is an elongated mixing space (6) running as a passageway along the length of the end wall (4). [Diagram 3] This is a modified example of the greenhouse shown in FIG. [Figure 4] 4 shows a greenhouse similar to that shown in FIG. 3. [Diagram 5] FIG. 5 is a three-dimensional view of a greenhouse similar to FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The above-mentioned process may be carried out in a greenhouse as shown in Figures 1 to 3. Figure 1 shows a greenhouse with a gable roof (2), a floor (3), two end walls (4) and two side walls (5). The interior of the greenhouse (1) is a growing space (8) in which grape crops, flowers and leafy vegetables can be grown. Along one end wall (4) a row of openings (9) to the outside (10) is provided for direct entry of ambient air into the growing space (8). The openings (9) may be closable openings. The flow of ambient air into the greenhouse may be achieved by a ventilation device arranged in the opposite end wall (4) that draws air from within the growing space to the surroundings (10) (not shown in this figure). The one or more closable openings (9) are provided with one or more water pads (12). The water pads (12) for carrying out step (c) are connected to a supply conduit (12a) for supplying cold water and to a discharge conduit (12b) for discharging the used cold water. A supply conduit (12a) for supplying cold water is fluidly connected to an indirect heat exchanger (19) for cooling a water source. A discharge conduit (12b) for discharging used cold water is fluidly connected to a storage container (18). From this storage container (18) water is supplied to the indirect heat exchanger (19) where it is cooled to obtain cold water for the cooling medium (21). From the storage container (18) water is discharged via a conduit (22) to be used as irrigation water in the growing space (8). Fresh water may be added to the storage container (18) via a supply (23).

[0032] Figure 2 shows a variation of the greenhouse of Figure 1 in which there is an elongated mixing space (6) running as a passageway along the length of the end wall (4). Between the mixing space (6) and the growing space (8) there is a partition wall (16). At the upper end of this partition wall (16), below the trusses (24) forming part of the roof structure of the gable roof (2), there are one or more closable openings (11) along the length of the partition wall (16). The growing space (8) is provided with a number of parallel ventilation ducts (13). Each duct (13) has an air inlet section (14) provided with a ventilation device (20) for drawing air from the mixing space (6). The ducts (13), which are suitably tubes made of a flexible material, are provided with openings along their length for uniform distribution of air within the growing space.

[0033] Figure 3 is a variant of the greenhouse shown in figure 2. In this greenhouse, the mixing space (6) extends along the side wall (5). The mixing space (6) is fluidly connected to the outside (10) of the greenhouse by one or more openings (9) for ambient air in the roof (2). Alternatively, the opening (9) for ambient air of the mixing space (6) to the outside (10) of the greenhouse may be an opening in one of the side walls (5). The mixing space (6) is also fluidly connected to the growing space by one or more openings (11) such as those present in the upper half of the partition wall (16).

[0034] Next to the mixing space (6) a space for conditioned air (7) is shown. The mixing space (6) and the space for conditioned air (7) are separated from the growing space (8) present in the greenhouse (1) by a partition (16). The mixing space (6) and the space for conditioned air (7) are fluidly connected via one or more water pads (12) for carrying out step (c) and via a parallel air flow path (A), the water pads (12) being arranged parallel to the parallel flow path (B). The parallel air flow path (B) comprises one or more indirect heating units (15) for carrying out step (d). The parallel air flow path (B) is provided with air displacement means (27). Such a design with two parallel air flows (A and (B) makes it possible to obtain conditioned air having the desired low temperature and an acceptable relative humidity.

[0035] FIG. 4 shows a greenhouse similar to that of FIG. 3. Also shown is a heat pump (30) which transfers thermal energy from a first heat carrier fluid (31) to a second heat carrier fluid (33) acting as a heat sink, using a refrigeration cycle, to obtain a cooling medium (34) and a heated second heat carrier fluid (35) for use in step (b). The cooling medium (34) is stored in a storage container (36) and the heated second heat fluid is stored in a storage container (37). The night cooling medium (34) collected during the day and stored in the container (36) is used to cool the water source of the heat exchanger (19) via a circulation circuit (38). The cooled and heated water obtained in the heat exchanger (19) is supplied to one or more water pads (12) as in FIGS. 1 to 3. The greenhouse of FIG. 4 may also be used for a process of dehumidifying air according to the invention. The heat pump (30) may also be combined with the greenhouse shown in FIGS. 1 to 3.

[0036] Figure 5 is a three-dimensional view of a greenhouse similar to figures 3 and 4. The difference is the presence of a raised floor (17), which makes it possible to provide an emergency door (19).

[0037] Example 1 The greenhouse according to Fig. 1 is simulated, in which ambient air (10) of 36°C and 60% relative humidity is used. The temperature of the air in the cultivation area (8) is 28°C and the relative humidity (RH) is 80%. The control objective in this example is to reduce the temperature of the air in the cultivation area (8) and not increase the absolute humidity by supplying ambient air into the cultivation area through a water pad (12).

[0038] Within the water pad (12), the ambient air comes into contact with cold water having a temperature of 7° C. The air leaving the water pad (12) and entering the greenhouse has a temperature of 27° C. and a relative humidity of at least 90%.

[0039] In effect, some of the water, as present in the ambient air, condenses within the water pad due to the use of cold water.

[0040] Comparative experiment A Example 1 is repeated, except that the ambient air is contacted in the water pad (12) with water having a temperature of 20° C. This water is cooled or not cooled before contacting the ambient air. The air leaving the water pad (12) and entering the greenhouse has a temperature of 29.5° C. and a relative humidity of 95%.

[0041] In effect, a portion of the liquid water evaporates and becomes part of the air that leaves the water pad (12) and enters the greenhouse.

[0042] Example 2 The greenhouse according to Fig. 3 is simulated, in which ambient air (10) of 36°C and 70% relative humidity is used. The temperature of the air in the cultivation area (8) is 28°C and the relative humidity (RH) is 80%. The control objective in this example is to reduce the temperature of the air in the cultivation area (8) by feeding the ambient air into the cultivation area through a water pad (12).

[0043] In the mixing space (6), a volume fraction 3 of the ambient air (10) is mixed with a volume fraction 7 entering the mixing space from the growing area (8) through the opening (11). The resulting air mixture in the mixing space (6), called supply air, has a temperature of 30.5°C and a relative humidity of 78%. 90% by volume (vol%) of this supply air comes into contact with liquid water in the water pad (12) having a temperature of 6°C to obtain moist air having a temperature of 20°C and a relative humidity of 100%. The remaining 20% ​​by volume (vol%) of the supply air bypasses or otherwise circumvents the water pad (12) through the parallel air flow path (B) (as in FIG. 3) and is mixed with the moist air to obtain conditioned air having a temperature of 22°C and a relative humidity of 95%. In this example, the air in the parallel air flow path (B) is not heated. The conditioned air discharged to the growing area through the tube (13) has a temperature of 22°C and a relative humidity of 95%.

[0044] Example 3 Example 2 is repeated, except that the air in the parallel air flow path (B) is heated to increase its enthalpy by about 5 kJ / kg. The resulting conditioned air in the space (7) has a temperature of 24.7°C and a relative humidity (RH) of 86%. As in Example 2, the conditioned air has a lower temperature than the air in the growing area and is therefore suitable for reducing the temperature of the growing area (8) when it is supplied to the growing area via the ventilation duct (13).

[0045] Comparative experiment B This calculated experiment shows how to cool the air in the growing section in a greenhouse as in FIG. 2, using the same ambient air as in examples 2 and 3, and with the same starting conditions as in examples 2 and 3. In the water pad, the ambient air comes into contact with water having a temperature of 20° C. The resulting mixture in the mixing space (6) has a temperature of 27.3° C. and a relative humidity of 95%. To obtain the same relative humidity as in examples 2 or 3, this air must be heated up to 28.5° C., at which point cooling of the growing section (8) becomes impossible.

Claims

1. A process for lowering or maintaining the temperature within a cultivation space provided in a greenhouse, (a) To obtain supply air, the steps include collecting ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space, (b) In order to obtain chilled water, the step of lowering the temperature of the water source by indirect heat exchange with a cooling medium, (c) A step of bringing a portion of the supply air into direct contact with chilled water, wherein the temperature of the chilled water is lower than the dew point of the supply air, the supply air is cooled, thereby obtaining cooled air as conditioned air and used chilled water, and discharging the conditioned air into the cultivation space. A process for reducing or maintaining the temperature within a growing space provided in a greenhouse, comprising the following components.

2. The process according to claim 1, wherein in another step (d), ambient air, air from a growing space, and / or a mixture of ambient air and air from a growing space not subjected to step (c) are mixed with cooling air in order to obtain conditioned air.

3. The process according to claim 2, wherein ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space not subjected to step (c) are heated to a higher temperature before being mixed with cooling air.

4. The process according to any one of claims 1 to 3, wherein the direct contact in step (c) takes place within a vertically extending wet screen, in which cold water flows downward and supply air passes laterally through the wet screen.

5. The process according to any one of claims 1 to 3, wherein the chilled water is more than 5°C lower than the dew point of the supply air.

6. The process according to any one of claims 1 to 3, wherein the relative humidity of the ambient air exceeds 50%, and the wet-bulb temperature of the ambient air is equal to or greater than the dry-bulb temperature of the greenhouse air.

7. The process according to any one of claims 1 to 3, wherein the temperature of the cold water is between 5 and 10°C.

8. The process according to any one of claims 1 to 3, wherein used chilled water is the water source in step (b).

9. The process according to any one of claims 1 to 3, wherein water present in the supply air condenses in step (c) to become part of the used chilled water.

10. The process according to claim 9, wherein some or all of the used cold water is used as irrigation water in the growing space.

11. The process according to any one of claims 1 to 3, wherein step (b) is performed by utilizing a heat pump.

12. The process according to claim 11, wherein a heat pump transfers thermal energy from a first heat carrier fluid (preferably water) to a second heat carrier fluid (preferably water) acting as a heat sink using a refrigeration cycle, thereby obtaining a cooling medium and a heated second heat carrier fluid for use in step (b).

13. The process according to claim 12, wherein step (c) is performed during part or all of the night, in step (c2), during part or all of the day, a portion of the supply air is brought into contact with a source of heated water, as a result the supply air is cooled to a temperature close to the wet-bulb temperature by the evaporation of a portion of the source of heated water, thereby obtaining cooled air as conditioned air, which is discharged into the growing space, and in step (b2), a source of heated water is obtained by indirect heat exchange with a heated second heat carrier fluid.

14. The process according to claim 13, wherein the direct contact in step (c2) takes place within a vertically extending wet screen, where a source of heated water flows downward and supply air passes laterally through the wet screen.

15. A greenhouse (1) having a roof (2), a floor (3), two end walls (4), two side walls (5), and an elongated mixing space (6) adjacent to an elongated space (7) for regulated air, The mixing space (6) and the space for regulated air (7) are separated from the cultivation space (8) located within the greenhouse (1). The mixing space (6) is fluidly connected to the outside (10) of the greenhouse by one or more openings (9) for ambient air, and is fluidly connected to the cultivation space by one or more openings (11). The mixing space (6) and the space for conditioned air (7) are fluidly connected via one or more water pads (12) and via a parallel air passage (B), the water pads (12) are arranged parallel to the parallel passage (B), The cultivation space (8) is equipped with multiple parallel ventilation conduits (13), each conduit (13) having an air inlet (14) where a ventilation device (20) is provided, the air inlet (14) is fluidly connected to a space (7) for regulated air, the water pad is connected to a cold water supply unit and a used cold water discharge unit, and the cold water supply unit is fluidly connected to an indirect heat exchanger for cooling the water source. The greenhouse in question.

16. The greenhouse according to claim 15, wherein the parallel airflow path comprises one or more indirect heating units (15).

17. A greenhouse according to any one of claims 15 to 16, wherein the parallel air passage (B) is provided with an air exchange means.

18. The greenhouse according to any one of claims 15 to 16, wherein the opening (9) to the outside (10) of the greenhouse for ambient air in the mixed space (6) is an opening in the roof (2).

19. The greenhouse according to any one of claims 15 to 16, wherein the opening (9) to the outside (10) of the greenhouse for ambient air in the mixing space (6) is an opening in one of the end walls (4) or one of the side walls (5).

20. The greenhouse according to any one of claims 15 to 16, wherein the mixing space (6) and the space for conditioned air (7) are each a single space.

21. A greenhouse according to any one of claims 15 to 16, wherein the mixed space (6) is defined by a roof (2), an end wall (4) or a side wall (5), a substantially vertical partition wall (16) spaced apart from the end wall (4) or side wall (5) and extending substantially parallel to the end wall (4) or side wall (5), and a floor (3) or a substantially horizontally raised partition floor (17) spaced apart from the floor (3).

22. The process according to any one of claims 1 to 3, carried out in the greenhouse according to any one of claims 15 to 16.

23. A process for lowering or maintaining the temperature within a cultivation space provided in a greenhouse, (a) To obtain supply air, the steps include collecting ambient air, air from the growing space, and / or a mixture of ambient air and air from the growing space, (b) A step of obtaining a cooling medium and a heated second heat carrier fluid by a heat pump, wherein the heat pump transfers thermal energy from a first heat carrier fluid (preferably water) to a second heat carrier fluid (preferably water) acting as a heat sink using a cooling cycle, thereby obtaining a cooling medium and a heated second heat carrier fluid. (b1) A step of obtaining chilled water by lowering the temperature of the first water source to a lower temperature through indirect heat exchange with a cooling medium, (b2) A step of obtaining a source of heated water by indirect heat exchange with a heated second heat carrier fluid, (c1) A step in which, during part or all of the night, a portion of the supply air is brought into direct contact with the chilled water obtained in step (b1), wherein the temperature of the chilled water is lower than the dew point of the supply air, the supply air is cooled, thereby obtaining cooled air as conditioned air and used chilled water, and the conditioned air is discharged into the cultivation space. (c2) A step in which, during part or all of the daytime, a portion of the supply air is brought into direct contact with the supply source of heated water obtained in step (b2), wherein the supply air is cooled to a temperature close to the wet-bulb temperature by the evaporation of a portion of the supply source of heated water, thereby obtaining cooled air as conditioned air, and the conditioned air is discharged into the cultivation space. A process for reducing or maintaining the temperature within a growing space provided in a greenhouse, comprising the following components.

24. A process for dehumidifying the air present in the cultivation space provided inside a greenhouse, (b) A step of obtaining a cooling medium and a heated second heat carrier fluid by a heat pump, wherein the heat pump transfers thermal energy from a first heat carrier fluid (preferably water) to a second heat carrier fluid (preferably water) acting as a heat sink using a cooling cycle, thereby obtaining a cooling medium and a heated second heat carrier fluid. (b1) A step of obtaining chilled water by lowering the temperature of the first water source to a lower temperature through indirect heat exchange with a cooling medium, (cc) A step of bringing a portion of the air from the cultivation area into direct contact with the cold water obtained in step (b1) within a vertically extending humid screen, wherein the cold water flows downward through the humid screen, the air from the cultivation area passes laterally through the humid screen, the temperature of the cold water is lower than the dew point of the air from the cultivation area, thereby obtaining dehumidified air, and discharging the dehumidified air into the cultivation area. A process for dehumidifying the air present in a cultivation space within a greenhouse, which includes the following features.

25. The process according to claim 24, wherein the heated second heat carrier fluid is used to heat the air, irrigation water and / or any plants in a cultivation section, either directly or via another heat transfer medium.

26. Use of a greenhouse according to any one of claims 15 to 16 for carrying out the process according to any one of claims 1 to 3 or 23 in the summer, and the process according to claim 24 or 25 in the spring, autumn and / or winter.

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