Earth tubes

Abstract

A method and system for forecasting and optimizing the performance of earth tube air exchange systems using machine learning algorithms. The invention receives measured exit air temperature data across various annual periods and outdoor temperature ranges, determines predicted temperature differences across the earth tube, and provides these predictions to HVAC design or operation modules. The system refines its forecasts over time based on actual outcomes, generates alerts or recommendations when performance deviates from thresholds, and stores both forecasted and actual data for long-term analysis and optimization. This approach enables improved accuracy in system design, operation, and maintenance, resulting in enhanced energy efficiency and reliability.

Description

[0001] EARTH TUBES

[0002] BACKGROUND

[0003] 1. Technical Field

[0004] This disclosure relates generally to heat and air conditioning and in particular to methods, and systems for designing and constructing earth tube heating and cooling structures for buildings.

[0005] 2. Description of Related Art

[0006] Heating and air conditioning of buildings and other structures is common requirement for occupant comfort. Such heating and air conditioning commonly uses energy in the form of fossil fuels or electricity to supply heat to or remove heat from the interior of the building. Such energy usage is frequently a source of inefficiency for the building, and requires compromises to be made, either in desired energy usage or performance. Occupied spaces also require fresh air to be supplied to the building at designed levels to remove contaminants generated within the building or introduce fresh air.

[0007] One known method of improving energy requirements for heating and cooling a building is to use free sources of pre-heating or cooling incoming ventilation air, such as through the use of earth tubes. Earth tubes are air conduits extending from an environment to a building interior which are located under ground for a distance of their length. The earth tube is able to warm incoming air during winter months and cool the incoming air during summer months from an ambient temperature to closer to a ground temperature.

[0008] Disadvantageously, earth tubes and in particular their performance for a given location and design may be variable and their expected benefit may be difficult to predict. Accordingly, although earth tube designs may provide improved building efficiency, such efficiency may not be accurately predictable and therefore other heating and cooling equipment may be required to be over sized to account for potential differences between the expected and actual design performance of the earth tube system. SUMMARY OF THE DISCLOSURE

[0009] According to a first embodiment of the present disclosure is a system for heating and cooling a building using earth tubes, comprising at least one earth tube configured to be buried underground and to extend between an exterior air intake and an interior air outlet of the building, a fan or blower operatively connected to the earth tube to induce airflow through the earth tube, a control system configured to determine a predicted temperature difference across the earth tube for each measured air exit temperature and an interface to provide the predicted temperature of the air exiting the earth tube to at least one of a design module or an hvac design or operation module.

[0010] The earth tube may be constructed from a material selected from the group consisting of high-density polyethylene (HDPE), or concrete. The earth tube may be installed at a depth sufficient to maintain a substantially constant temperature throughout the year. The system may further comprise a condensate drainage system configured to remove moisture accumulating within the earth tube. The control system may be further configured to selectably modulate the operation of one or more components in the HVAC system in response to the predicted air temperature leaving the earth tube.

[0011] According to a further embodiment of the present disclosure is a method for heating method for heating and cooling a building using earth tubes, comprising drawing exterior air into at least one earth tube buried underground, passing the air through the earth tube to allow heat exchange between the air and the surrounding earth, delivering the pre-conditioned air to the interior of the building and determining utilizing a control system, a future exit air temperature from the earth tube based on historical data, current environmental conditions, and dynamically adjusting system parameters in advance to optimize thermal performance and energy efficiency.

[0012] The method may further comprise draining condensate from the earth tube to prevent accumulation of moisture. The earth tube is installed at a depth that provides a substantially stable temperature for heat exchange year-round. The predictive analytics module utilizes machine learning algorithms to refine its forecasts over time based on actual measured outcomes. The method may further comprise generating alerts or recommendations for maintenance or operational adjustments when predicted performance deviates from predefined thresholds. The method may further comprise storing the forecasted and actual performance data in a database for long-term analysis and system optimization.

[0013] According to a further embodiment of the present disclosure is a system for heating method of operating an earth tube air exchange system comprising receiving a data set representing having a plurality of measured exit air temperatures, each of the plurality of measured exit air temperatures corresponding to at least one annual time period and within at least one outdoor air temperature range, determining a predicted temperature difference across the earth tube for each measured air exit temperature and providing the temperature difference to at least one of an hvac design or operation module. The method may further comprise measuring an air temperature entering the earth tube.

[0014] Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constitute part of the disclosure. Each drawing illustrates exemplary aspects wherein similar characters of reference denote corresponding parts in each view,

[0017] Figure 1 is a schematic of an earth tube system for a building.

[0018] Figure 2 is a flowchart of a design process for designing the earth tube system of Figure 1 .

[0019] Figure 3 is a flowchart of a design process for designing the earth tube system of Figure 1 .

[0020] Figure 4 is an illustration of a data structure of measured data for use in the method of Figure 3. Figure 5 is an illustration of a data structure of calculated temperature change of air through the earth tube of Figure 1.

[0021] Figure 6 is a schematic of a system for conducting the design method of the earth tube of Figure 2.

[0022] Figure 7 is a plan view of a site layout of a plurality of earth tubes under a building according to a first embodiment of the present disclosure.

[0023] Figure 8 is a side view of the layout of Figure 7.

[0024] Figure 9 is a perspective view of an intake for use with the earth tubes of the present disclosure.

[0025] Figure 10 is a side view of the intakes of Figure 9.

[0026] Figure 11a-c are views of a manifold for use with the system of Figure 7.

[0027] Figure 12 is a side layout view of a building incorporating earth tubes according to a further embodiment of the present disclosure.

[0028] Figure 13 is site plan of a system utilizing earth tubes across distributed buildings according to a further embodiment of the present disclosure.

[0029] Figure 14 is a site plan of a system according to a further embodiment of the present disclosure.

[0030] Figure 15 is perspective view of an intake plenum for use with an earth tube according to a further embodiment of the present disclosure.

[0031] Figure 16 is a side view of the intake plenum of Figure 16.

[0032] Figure 17 is a view of an intake for use with earth tubes according to a further embodiment of the present disclosure.

[0033] Figure 18 is a plan view of a building incorporating earth tubes according to a further embodiment of the present disclosure.

[0034] Figure 19 is a layout of a plurality of earth tubes across an area according to a further embodiment of the present disclosure.

[0035] Figure 20 is a side view of a layout of a plurality of earth tubes through a region according to a further embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Referring to Figure 1 , an exemplary earth tube system illustrated generally at 10. The earth tube system 10 comprises a tube 12 extending from an ambient location to an interior of a building 14. The earth tube extends under a ground surface 16 for a designated length 18. The earth tube extends to a distal end 20 forming an air intake of ambient air which is drawn through the earth tube to the building 14.

[0037] Turning now to Figure 2, the sizing (diameter) of the earth tube 12 may be conducted by conventional methods. In particular, the required make up air for a building may be dictated by local building codes, conventional practice or as desired by a building owner or occupant. The required air volume may then be utilized to select the appropriate diameter of earth tube for that building so as to achieve a desired air flow velocity through the earth tube. The routing, material and other construction details may then be determined as illustrated in Figure 2.

[0038] T urning now to figure 3, and with reference to Figures 4 and 5, a processor of the design and / or management system (100 as illustrated in Figure 6) may include a database with a data set containing measured exit air temperatures from comparable previous or existing earth tube installations. The data set may be chosen by a user or by the processor based on similarities to the earth tube to be constructed, including, without limitation, geographic proximity, soil type, altitude, earth tube material type or comparable weather patterns. The processor 102 then receives standardized or other official weather data for the design location, including average, minimum and maximum temperatures and / or temperature distributions by time of year. The measured exit temperature as shown in Figure 4, may be divided into a plurality of time periods, such as, by way of non-limiting example, month, day or week of the year as well as ambient temperature ranges for each time period. In particular, the measured exit air temperature may be a compilation of the exit air temperatures from previous earth tubes, for each time period and within each temperature range, such that an expected exit temperature is provided for each time period and within each potential temperature range. The processor 102 then utilizes the measured exit temperature to determine an expected temperature difference through the air tube for each time period and within each temperature range. By way of non-limiting example, during period 1 , and for an ambient air temperature between 1 and 10 degrees Celsius, the expected exit air temperature is 8 degree Celsius. Accordingly, the processor may average the temperature range to 5 degrees Celsius within the range of 1- 10 degrees Celsius giving an expected temperature difference through the earth tube of an increase of 3 degrees within that time period and ambient temperature range. In particular, the processor utilizes the expected temperature difference to calculate the expected incoming air temperature based on the expected or actual outdoor air temperature. The processor may then use expected incoming air temperature to either adjust the incoming air temperature for the HVAC system (resulting in a reduced capacity required and therefore greater efficiency) or to control the operation of the heating or cooling elements of the HVAC system in a building operation capacity.

[0039] The length of the pipe may be selected based on the maximum site constraints for that construction location as well as lengths over which temperature changes is minimal and therefore longer lengths provides reduced benefit when including costs and air pressure losses.

[0040] In construction, the earth tube 12 may be located in the ground at any desired time. The earth tube may be located under ground at a depth as dictated by the local climate, depth of frost penetration, need to protect the earth tube in ground and avoid other buried objects.

[0041] The earth tube 12 may be formed of any suitable material including, without limitation, high-density polyethylene (HDPE) or precast concrete. It will be appreciated that a plurality of sections of pipe may utilized that are connected to each other for larger diameters of pipe whereas smaller diameters may utilize a continuous length of pipe. It will furthermore be appreciated that where pipe sections are joined to each other, care should be taken to ensure that such connections are watertight.

[0042] The earth tube 12 may be installed in location utilizing methods, site preparation and geotechnical designs as are known for municipal water, storm and sewage installation. In particular, it has been found that locating such earth tubes 12 along such site preparations and coverings along gradients that are substantially horizontal and flat has been useful to prevent the accumulation of water and or debris within the earth tube. Furthermore it has been found that ensuring that the earth tube 12 is substantially sealed to prevent the ingress of ground water has also be advantageous to prevent moisture and contaminant including in the system.

[0043] Turning now to Figure 6, the design and / or operation system 100 comprises a processor 102 , and database 104 and optional memory 106. The memory 106 may stores machine instructions that, when executed by the processor 102, cause the processor 102 to perform one or more of the operations and methods described herein. The memory 106 of any known type including a cache memory unit for temporary local storage of instructions, data, or computer addresses. The design and operation system 100 may further include the database 104 either internally or externally and may be of any conventional type operable to store the information and fields required by the processor information.

[0044] More generally, in this specification, the term "processor" is intended to broadly encompass any type of device or combination of devices capable of performing the functions described herein, including (without limitation) other types of microprocessors, microcontrollers, other integrated circuits, other types of circuits or combinations of circuits, logic gates or gate arrays, or programmable devices of any sort, for example, either alone or in combination with other such devices located at the same location or remotely from each other. Additional types of processor(s) will be apparent to those ordinarily skilled in the art upon review of this specification, and substitution of any such other types of processor(s) is considered not to depart from the scope of the present invention as defined herein. In various embodiments, the processor 102 can be implemented as a single-chip, multiple chips and / or other electrical components including one or more integrated circuits and printed circuit boards.

[0045] Computer code comprising instructions for the processor(s) to carry out the various embodiments, aspects, features, etc. of the present disclosure may reside in the memory 106, within the processor 102 or be obtained from outside the system. The code may be broken into separate routines, products, etc. to carry forth specific steps disclosed herein. In various embodiments, the processor 102 can be implemented as a single-chip, multiple chips and / or other electrical components including one or more integrated circuits and printed circuit boards. The processor 102 together with a suitable operating system may operate to execute instructions in the form of computer code and produce and use data. By way of example and not by way of limitation, the operating system may be Windows-based, Mac-based, or Unix or Linux-based, among other suitable operating systems. Operating systems are generally well known and will not be described in further detail here. In particular, the processor 102 may be include functions of voice and text recognition and natural language processing. Optionally, the processor 102 may include adaptive algorithms including by way of non-limiting example, machine learning algorithms programmed to communicate with an ability to interpret answers from the users and provide further analysis and interpretation thereof. Such algorithms may include regression analysis, natural language processing, or any other machine learning methods as are available.

[0046] Memory 106 may include various tangible, non-transitory computer-readable media including Read-Only Memory (ROM) and / or Random-Access Memory (RAM). As is well known in the art, ROM acts to transfer data and instructions unidirectionally to the processor 102, and RAM is used typically to transfer data and instructions in a bi-directional manner. In the various embodiments disclosed herein, RAM includes computer program instructions that when executed by the processor 102 cause the processor 102 to execute the program instructions described in greater detail below. More generally, the term “memory” as used herein encompasses one or more storage mediums and generally provides a place to store computer code (e.g., software and / or firmware) and data. It may comprise, for example, electronic, optical, magnetic, or any other storage or transmission device capable of providing the processor 102 with program instructions. Memory 106 may further include a floppy disk, CD-ROM, DVD, magnetic disk, memory chip, ASIC, FPGA, EEPROM, EPROM, flash memory, optical media, or any other suitable memory from which processor 102 can read instructions in computer programming languages.

[0047] The processor 102 may also interface with input and output devices and / or building management systems including HVAC management. In particular, the processor 102 may include an interface with an ambient and / or earth tube exit temperature sensors 110 operable to measure the temperature of the air entering and exiting the earth tube so as to measure the actual temperature difference achieved by the earth tube. The processor may then be operable to update the measured data tables as illustrated in Figure 4 using one or more machine learning algorithms or display the results to a user through a user interface 108 and / or provide an expected temperature to the HVAC system controller 112.

[0048] It will be appreciated that the earth tubes 12 may be laid out proximate to the building in a plurality of arrangements. In particular, with reference to Figure 7, the earth tubes 12 may extend and be distributed under the floor of a building, such as, by way of non-limiting example a sports field. As illustrated in Figure 7, the system may comprise a plurality of earth tubes 12 extending and distributed under the sports field between an intake 20 and a collection manifold 21. The collection manifold 21 may be operably coupled to an intake pipe for the building HVAC system as is known. As illustrated in Figure 8, the intake manifold 20 may further include one or more intake openings 23 extending therefrom to atmosphere. In such a system, the earth tubes 12 are operable to be pre-heated or pre-cooled by the temperature within the building itself. As shown in Figures 9 and 10, the intake 23 may comprise an upwardly extending tube transitioning to a horizontal opening with louvers or the like across the surface thereof. An exemplary embodiment of an intake and / or collection manifold 21 or 23 is illustrated in Figures 11a-c wherein the manifold includes an open top connectable to an intake or HVAC system and a plurality of openings operable to receive the earth tubes therein. Optionally, the earth tubes 10 may be distributed under the footprint of the building 15 along non-straight paths, such as illustrated in Figure 19. The exact paths of the earth tubes may be selected to evenly distribute coverage of the footprint. Furthermore, as illustrated in Figure 20, the earth tubes may be distributed across different depths within a region 260 so as to utilize the region as a heat sink.

[0049] Turning now to Figure 12, a further embodiment of the present disclosure is shown for a building 14 having a plurality of earth tubes 12 extending thereto. In particular the earth tubes may extend to one or more of an interior space, an air handing unit 200 as an intake to be optionally mixed with a portion of return air from the building interior. As illustrated in Figure 12, the air from within one or more interior space, including, by way of non-limiting example a courtyard as illustrated, may be supplied to and utilized as the input air of the condensing unit 202 thereby increasing system efficiency. This will be further increased where the air within the courtyard is also cooled before introduction thereto with an earth tube as illustrated.

[0050] Furthermore, the earth tubes may be distributed around a site between one ore more unit 230 may be provided with earth tubes 12 extending from a common intake 232 to each unit as illustrated in Figure 13. As further illustrated in Figure 14, each earth tube 12 may be located proximate to or along an existing water, sewage or other service line so as to be operable to draw residual heat from that exiting line as illustrated in Figure 12. It will also be appreciated that such intake position may be selected to be away from parking and other sources of pollutants.

[0051] Turning now to Figures 15 and 16, an intake or outlet plenum 240 for use with the earth tube 12 is illustrated. The plenum maybe sized to permit a worker to enter through a door 242 in a duct 244 extending upwardly therefrom with ladder rungs 246 or the like therein. It will be appreciated that the plenum assists with access to service or maintain the earth tube and may be coupled to an intake as set out above or the other HVAC equipment. As illustrated in Figure 17, the intake 250 may comprise a grate, screen or the like passing through a hill or angled surface in the ground with retaining walls 256 or the like positioned to prevent obstruction to the intake.

[0052] It will be further appreciated that the earth tube 12 may be located at a position selected to absorb excess heat from the building as set out above or another structure. In particular as set out above, the earth tubes may be located under the building. As illustrated in Figure 18, the earth tubes 12 may be positioned to extend parallel to and adjacent to the exterior of a building to an intake 20. It will also be appreciated that such intake position may be selected to be away from parking and other sources of pollutants.

[0053] While specific embodiments have been described and illustrated, such embodiments should be considered illustrative only and not as limiting the disclosure as construed in accordance with the accompanying claims.

Claims

CLAIMS1. A system for heating and cooling a building using earth tubes, comprising: at least one earth tube configured to be buried underground and to extend between an exterior air intake and an interior air outlet of the building; a fan or blower operatively connected to the earth tube to induce airflow through the earth tube; a control system configured to determine a predicted temperature difference across the earth tube for each measured air exit temperature; and an interface to provide the predicted temperature of the air exiting the earth tube to at least one of a design module or an hvac design or operation module.

2. The system of claim 1 wherein the earth tube is constructed from a material selected from the group consisting of high-density polyethylene (HDPE), or concrete.

3. The system of claim 1 wherein the earth tube is installed at a depth sufficient to maintain a substantially constant temperature throughout the year.

4. The system of claim 1 further comprising a condensate drainage system configured to remove moisture accumulating within the earth tube.

5. The system of claim 1 wherein the control system is further configured to selectably modulate the operation of one or more components in the HVAC system in response to the predicted air temperature leaving the earth tube.

6. A method for heating and cooling a building using earth tubes, comprising: drawing exterior air into at least one earth tube buried underground; passing the air through the earth tube to allow heat exchange between the air and the surrounding earth; delivering the pre-conditioned air to the interior of the building; determining utilizing a control system, a future exit air temperature from the earth tube based on historical data, current environmental conditions, and dynamically adjusting system parameters in advance to optimize thermal performance and energy efficiency.

7. The method of claim 6 further comprising draining condensate from the earth tube to prevent accumulation of moisture.

8. The method of claim 6 wherein the earth tube is installed at a depth that provides a substantially stable temperature for heat exchange year-round.

9. The method of claim 6 wherein the predictive analytics module utilizes machine learning algorithms to refine its forecasts over time based on actual measured outcomes.

10. The method of claim 9 further comprising generating alerts or recommendations for maintenance or operational adjustments when predicted performance deviates from predefined thresholds.

11. The method of claim 6, further comprising storing the forecasted and actual performance data in a database for long-term analysis and system optimization.

12. A method of operating an earth tube air exchange system comprising: receiving a data set representing having a plurality of measured exit air temperatures, each of the plurality of measured exit air temperatures corresponding to at least one annual time period and within at least one outdoor air temperature range; determining a predicted temperature difference across the earth tube for each measured air exit temperature; and providing the temperature difference to at least one of an hvac design or operation module.

13. The method of claim 12 further comprising measuring an air temperature entering the earth tube.

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