CA3086358A1

CA3086358A1 - Air heating system

Info

Publication number: CA3086358A1
Application number: CA3086358A
Authority: CA
Inventors: Christian Vachon
Original assignee: Trigo Energies Inc
Current assignee: 9494-2851 QUEBEC INC.
Priority date: 2017-12-21
Filing date: 2018-12-19
Publication date: 2019-06-27
Also published as: WO2019119133A1

Abstract

An air system for a building or process comprises an indoor air exhaust circuit for venting air from inside the building; and an outdoor air inlet circuit for admitting outdoor air into the building, the outdoor air inlet circuit being fluidly isolated from the indoor air exhaust circuit, the indoor air exhaust circuit and the outdoor air inlet circuit being in heat exchange relationship along at least a physically overlapping portion of a length thereof, said outdoor air inlet circuit including a solar air collector within said physically overlapping portion to allow for combined solar and heat recovery heating within a single integrated unit.

Description

AIR HEATING SYSTEM
TECHNICAL FIELD
[0001] The application relates generally to air systems for buildings and processes, and more particularly, to a combined solar and heat recovery air heating system.
BACKGROUND OF THE ART

[0002] Solar heat collectors can be used to heat a fluid, such as air or water, with solar energy. The solar collectors can be mounted on houses, commercial buildings, and other structures to provide heating by harnessing the solar energy. The solar collectors can also provide heated air to industrial processes. The heated air is often reheated with conventional methods to meet temperature requirements. In cold weather or during winter, a considerable consumption of heating energy may be required to meet the temperature requirements, usually by using gas-fired equipment.
SUMMARY

[0003] In one aspect, there is provided a solar air heating system comprising:
a solar heat collector extending between a first end and a second end, the solar heat collector having an inlet configured to receive fresh air and an outlet configured to discharge pre-heated air in a process or housing, the outlet disposed at the second end of the solar heat collector; an exhaust duct extending between a first end and a second end, the exhaust duct configured to receive stale air from the process or housing and discharge the stale air outside the process or housing, the exhaust duct being fluidly sealed from the solar heat collector to avoid stale air from contaminating the fresh air; and a heat exchanger disposed between the solar heat collector and the exhaust duct with at least a portion of the solar heat collector in heat exchange relation with at least a portion of the exhaust duct, the heat exchanger disposed upstream of the outlet of the solar heat collector relative to a flow of the fresh air within the solar heat collector.

[0004] In another aspect, there is provided a method for delivering heated fresh air inside a housing, the method comprising exhausting air from inside the housing to outside the housing; heating fresh air located outside the housing through captured solar energy; and while heating the fresh air with the captured solar energy, concurrently imparting thermal energy from the exhausted air to the fresh air through a heat exchange relationship between the exhausted air and the fresh air.

[0005] In a further aspect, there is provided an air system for a building, comprising a solar air collector for pre-heating fresh outdoor air, the solar air collector having an outlet for discharging heated outdoor air inside the building; and an air-to-air heat exchanger integrated into the solar air collector to provide an additional heat source to pre-heat the fresh outdoor air while the fresh outdoor air flows through the solar air collector, the air-to-air heat exchanger defining an indoor air exhaust circuit having an inlet configured to be connected to an air exhaust line of the building and an outlet for venting indoor air from the building, the solar air collector defining an outdoor air inlet circuit fluidly isolated from the indoor air exhaust circuit to prevent mixing between the outdoor and indoor air streams, the outdoor air inlet circuit and the indoor air exhaust circuit having a heat exchange interface for allowing heat transfer between the outdoor air and indoor air streams upstream of the outlet of the solar air collector.

[0006] In a further aspect, there is provided an air system for a building, comprising an indoor air exhaust circuit for venting air from inside the building; and an outdoor air inlet circuit for admitting outdoor air into the building, the outdoor air inlet circuit being fluidly isolated from the indoor air exhaust circuit, the indoor air exhaust circuit and the outdoor air inlet circuit being in heat exchange relationship along at least a physically overlapping portion of a length thereof, said outdoor air inlet circuit including a solar air collector within said physically overlapping portion to allow for combined solar and heat recovery heating within a single integrated unit.
DESCRIPTION OF THE DRAWINGS

[0007] Reference is now made to the accompanying figures in which:

[0008] Figs. 1-2 are tridimensional schematic views of air system in accordance to a particular embodiment;

[0009] Fig. 3 is a side schematic view of the air system of Figs. 1-2;

[0010] Figs. 4-8 are schematic views of the air system in accordance to different alternatives of the air system;

[0011] Fig. 9 is an exploded schematic view of a solar heat collector of the air heating system;

[0012] Figs. 10-11 are schematic tridimensional views of the air system in accordance to different embodiments;

[0013] Figs. 12-13 are schematic views of the air system in accordance to different variants;

[0014] Fig. 14 is a schematic tridimensional view, sectioned, of an air channel;

[0015] Fig. 15 is a schematic cross-sectional view of a bracket;

[0016] Fig. 16 is a schematic cross-sectional view of the air channel;

[0017] Fig. 17 is a schematic cross-sectional view of the air channels connected in series;

[0018] Fig. 18 is a schematic cross-sectional view of the air channels mounted between a metal face and a wall;

[0019] Figs. 19-25 are schematic top views of the air system in accordance to different variants; and

[0020] Fig. 26 is schematic tridimensional view DETAILED DESCRIPTION

[0021] Figs. 1-2 illustrate an air system 10 mounted on a building 12 to ventilate air within the building 12. For instance, the air system 10 could be used in a process housed within the building 12.

[0022] The air system 10 can circulate two separate air steams. A fresh stream of air 14 is introduced into the building 12 while a stale stream of air 16 (indoor air) is exhausted from the building 12. The term "fresh stream of air" is intended to indicate at least one of air that is not altered by processing, unmixed with any other matter from the building 12 or the process, free from dirt, taint, volatile compounds and/or dust. The fresh stream of air can also indicate fresh air exterior from the building 12 or the process, and the like. The fresh air can also be referred to as "outdoor air" 14.
The term "stale stream of air" is intended to indicate at least one of air that is altered by processing, mixed with matter from the building 12 or the process, contains dirt and/or taint, used air from interior of the building 12 or the process, and the like. The stale air can also be referred to as "indoor air" 16.

[0023] The air system 10 can include one or more inlet circuits 18 to supply the fresh outdoor air 14 to the building 12, an air treatment system 20 connected to the inlet circuit 18 to treat the fresh outdoor air 14 before discharging the outdoor air 14 into the building 12 and one or more outlet circuits 22 to exhaust stale indoor air 16 from inside the building 12 to outside the building 12. In a particular embodiment, the air treatment system 20 can include a bypass damper. In a particular embodiment, the indoor air 14 can be heated in the building 12 or during the process. The air treatment system 20 can heat the outdoor air 16. In a particular embodiment, the air treatment system 20 includes a gas-fired air heater.

[0024] Fig. 3 illustrates a side view of the air system 10 mounted on the building 12.
In the embodiment shown, the inlet circuit 18 of the air system 10 includes a solar heat collector 24 mounted on a wall 26 of the building 12 to pre-heat the fresh outdoor air 14 passing through the solar heat collector 24 with solar energy.
The solar heat collector 24 is also shown in Figs. 1-2. It is understood that various types of solar heat collectors can be used. For instance, the solar heat collector 24 can be a glazed solar air heater that generally comprises a glass, polycarbonate or Lexan transparent cover placed in front of a dark solar absorber. The solar heat collector 24 can also be an unglazed solar air heater and includes transpired collector designs with the solar absorbing surface located outside facing the sun, unprotected by means of a glazing. Additional embodiments of the solar heat collector 24 are described, mutatis mutandis, in U.S. Publication Nos. 2010/0000520 and 2012/0312293, the disclosures of which are herein incorporated by reference in their entirety. Other possible configurations and designs of the solar heat collector 24 are described herein below in greater details with reference to Figs. 4-8.

[0025] The solar heat collector 24 extends between a collector inlet 28 and a collector outlet 30. Although the solar heat collector 24 is shown mounted on the side wall 26 of the building 12, it is understood that the solar heat collector 24 could also be mounted on a roof 32 of the building 12 or any other suitable part of the building 12 or field.

[0026] The collector outlet 30 is connected to the air treatment system 20 through an extension duct 34. The extension duct 34 can be thermally insulated. In an alternate embodiment, the solar heat collector 24 can extend to the air treatment system 20 without using the extension duct 34. In this case, the heat collector 24 can operate with a second fan (not shown), which pushes air into the heated space or process.

[0027] In use, the fresh outdoor air 14 is drawn into the solar heat collector 24. A
fan or the like can be used to draw the outdoor air 14. The outdoor air 14 is pre-heated by solar energy while traveling through the solar heat collector 24 and successively heated through the air treatment system 20. Alternately, the air exiting the solar heat collector 24 can be left unchanged or cooled through the air treatment system 20.

[0028] Still referring to Fig. 3, an air diffusion duct 36 may be connected to an outlet of the air treatment system 20 to discharge the outdoor air 14 into the building 12.
The air diffusion duct 36 can include multiple apertures 38 to supply the heated outdoor air 14 at specified locations within the building 12.

[0029] In the embodiment shown in Fig. 3, the outlet circuit 22 of the air system 10 includes an exhaust duct 40 for venting indoor or process air 16 outside of the building 12. An exhaust fan 42 can be used to positively push the indoor air 14 out of the exhaust duct 40. The exhaust duct extends 40 between an exhaust inlet located inside the building 12 and exhaust outlet 46 located outside the building 12.
At least a portion of the exhaust duct 40 can be contiguous to and in heat exchange relationship with the solar heat collector 24. In a particular embodiment, the exhaust inlet 44 is located toward and/or near the collector outlet 30 and the exhaust outlet 46 is located toward and/or near the collector inlet 28 such as to maximize a length of the contiguous portion between the exhaust duct 40 and the solar heat collector 24.

[0030] Although the solar heat collector 24 and the exhaust duct 40 are contiguous along at least a portion of the length thereof, the exhaust duct 40 is fluidly isolated from the solar heat collector 24 to prevent contamination of the outdoors stream 14 by the indoor exhaust air stream 16 discharged from the building or process.
Since the exhaust air or indoor air 16 can contain contaminants, at least the contiguous portion is maintained leakproof or airtight to prevent mixing between the outdoor air stream 14 and the indoor air stream 16. The two air streams 14, 16 may be confined to flow in segregated manner. In an embodiment, the exhaust duct 40 and the solar heat collector 24 are isolated from one another such that there is no flow between the two air streams 14, 16. For example, an insulation between the exhaust duct 40 and the solar heat collector 24 can also prevent any leaking between the outdoor air 14 flowing through the solar heat collector 24 and the indoor air 16 flowing through the exhaust duct 40. The solar heat collector 24 and the exhaust duct 40 are fluidly separated by a free-leak structure. The free-leak structure can include any arrangement to prevent and/or avoid fluid contamination between the two air streams 14, 16.

[0031] To ensure that the indoor air 16 does not leak into the outdoor air stream 14, the pressure in the two streams can be selected so that if there is any leak, for example if the system has been compromised, the leak will be from the outdoor stream 14 to exhaust air stream 16 and not the opposite. For example, only a leak from the solar heat collector 24 to the exhaust duct 40 may be possible by maintaining a higher pressure in the solar heat collector 24 relative to a pressure in the exhaust duct 40. The exhaust duct 40 can be maintained separate and sealed from the solar heat collector 24 to at least prevent the indoor air 16 to leak from the exhaust duct 40 to the solar heat collector 24.

[0032] The air system 10 includes a heat exchanger to provide heat exchange relationship between at least a portion of the solar heat collector 24 and the exhaust duct 40. The term "heat exchanger" is intended to include any device or configuration by means of which heat may be transferred from the indoor air stream 16 to the outdoor air stream 14 to heat the outdoor air 14 thereby. The heat exchanger can be selected to provide heat transfer between the outdoor and indoor air streams 14, 16. For example, the air streams 14, 16 are separated by a solid wall so that they do not mix and yet transfer heat from the indoor air stream 16 to the outdoor air stream 14. In a particular embodiment, the heat exchanger is a heat pipe system. For example, a portion of the exhaust duct 40 can be made from a thermally conductive material that interface the outdoor air stream 14 such as to release heat from the indoor air stream 16 to the outdoor air stream 14 flowing through the solar heat collector 24. In the particular embodiment shown in Fig. 3, the heat exchanger is located upstream of the collector outlet 30 relative to the flow of the outdoor air stream 14 within the solar heat collector 24. The heat exchanger can be placed

33 along the contiguous portion between the solar heat collector 24 and the exhaust duct 40.
[0033] The two air streams 14, 16 can flow through the heat exchanger in a counter-flow configuration, a parallel-flow configuration and/or a transversal-flow configuration. With a counter-flow configuration the air streams 14, 16 travel through the heat exchange section of the air system 10 in substantially opposite directions to each other whereas a parallel flow configuration will have the two air streams 14, 16 flowing in the same direction.

[0034] The solar heat collector 24 and the exhaust duct 40 can be integrated into a solar heat exchanger unit. An example of the integrated solar heat exchanger unit is shown in Fig. 26 at 150. The solar heat exchanger unit 150 can be manufactured and sold as a single unit. The solar heat exchanger unit 150 can be mounted on to the building 12 and connected to existing inlet and outlet circuits 18, 22 of the building 12 or the process. The solar heat exchanger unit 150 can thus preheat the outdoor air stream 14 concurrently with solar energy and with heat recovery from the indoor air stream 16. In the example shown in Fig. 26, the outdoor air stream 14 and the indoor air stream 16 are in cross-flow heat exchange relationship. The exhaust duct 40 includes an exhaust air plenum 40A (hot side), an exhaust air plenum (cold side) and exhaust pipe channels 40C fluidly connecting the hot air plenum 40A
and the cold air plenum 40B. The hot exhaust air plenum 40A is upstream of the cold exhaust air plenum 40B relative to a flow of the indoor air 16 through the solar heat exchanger unit 150. As shown in Fig. 26, there is a clear separation 152 between the solar heat collector 24 and the exhaust air plenums 40A, 40B. The separation 152 adjacent the cold exhaust air plenum 40B minimizes heat transfer between the air within the solar heat collector 24 and the cold exhaust air plenum 40B. The exhaust pipe channels 152 can include insulation 154 around segments of the pipes 152 between the exhaust air plenums 40A, 40B and the solar heat collector 24. In use, relatively hot indoor air 16 flows through the solar heat collector 24 from the hot exhaust air plenum 40A to the cold exhaust air plenum 40B.
Within the solar heat collector 24, thermal energy is transferred from the indoor air 16 to the outdoor air 14 concurrently with the solar energy being transferred to the outdoor air 14. The relatively cold indoor air 16 is then exhausted through the exhaust outlet 46.

[0035] Fig. 4 illustrates an example of an integrated solar collector and heat recovery unit or solar heat exchanger unit 50 of the air system 10. The solar heat exchanger unit 50 includes a solar heat collector 52 with a sheet metal face 54 and a back face 56 such that the outdoor air stream 14 flows between the metal face 54 and the back face 56. Incoming fresh outdoor air 14 can also flow behind the exhaust duct 40, that is, between the back face 56 and wall 26 of the building 12.
The sheet metal face 54 can absorb solar radiation S and, thus, be heated by the solar energy. In the embodiment shown in Fig. 4, the outdoor air stream 14 flows upward while the indoor air stream 16 flows downward through the exhaust duct 40.
The outdoor air 14 is pre-heated in counter-flow with the indoor air 16.

[0036] Fig. 5 illustrates a solar heat exchanger unit 58 in accordance to a particular embodiment. The solar heat exchanger unit 58 includes a solar heat collector with a perforated sheet metal face 62. The remaining configuration of the solar heat exchanger unit 58 shown in Fig. 5 has a similar configuration to the solar heat exchanger unit 50 shown in Fig. 4. The outdoor air 14 is pre-heated in counter-flow with the indoor air 16.

[0037] Fig. 6 illustrates a solar heat exchanger unit 64 in accordance to a particular embodiment. The solar heat exchanger unit 64 includes a solar heat collector with a glazing 68. The term glazing relates to the use of transparent materials (e.g.
glass) and is intended to indicate, for example, a window and the like. In the particular embodiment using the glazing 68, the back face 56 is made from absorptive material to absorb the solar energy from the solar radiation and thus heat the surrounding air. The remaining configuration of the solar heat exchanger unit 64 shown in Fig. 6 has a similar configuration to the solar heat exchanger unit shown in Fig. 4. The outdoor air 14 is pre-heated in counter-flow with the indoor air 16.

[0038] Fig. 7 illustrates a solar heat exchanger unit 70 in accordance to a particular embodiment. The solar heat exchanger unit 70 includes a solar heat collector with a perforated glazing 74. The remaining configuration of the solar heat exchanger unit 70 shown in Fig. 7 has a similar configuration to the solar heat exchanger unit 64 shown in Fig. 6. The outdoor air 14 is pre-heated in counter-flow with the indoor air 16.

[0039] Fig. 8 illustrates a solar heat exchanger unit 76 with a parallel-flow configuration. The remaining configuration of the solar heat exchanger unit 76 shown in Fig. 8 has a similar configuration to the solar heat exchanger unit shown in Fig. 4. The outdoor air stream 14 flows between the metal face 54 and the back face 56. The collector inlet 28 is located toward the exhaust inlet 44, i.e. toward the top of the wall 26, whereas the collector outlet 30 is located toward the exhaust outlet 46, i.e. toward the bottom of the wall 26. Thus, the outdoor air 14 is pre-heated in parallel flow with the indoor air 16. The solar heat exchanger units 50, 58, 64, 70, 76 can be configured such as the outdoor air 14 is pre-heated in a cross-flow with the indoor air 16, both air streams 14, 16 moving upward, downward or sideways, depending on site-specific conditions.

[0040] Referring to Fig. 9, a solar heat collector 80 according to a particular embodiment is shown in an exploded view. The solar heat collector 80 includes a plurality of air channels 82 connected in series. In this particular embodiment, each unitary air channel 82 includes three longitudinally extending sub-channels 84 or cavities to transmit the outdoor air 14 through the solar heat collector 80.
In an alternate embodiment, the air channel 82 can include one sub-channel 84 or any number of sub-channels 84. The sub-channels 84 can be provided in bundles to ease assembly of the solar heat collector 80 on site.

[0041] The solar heat collector 80 includes a collector plenum 86 fluidly connected to the air channels 82. In the embodiment shown in Fig. 9, the collector plenum 86 is connected to an end of the air channels 82. The outdoor air 14 flows through the air channels 82 to the collector plenum 86 and hence to the collector outlet 30.

[0042] The solar heat collector 80 includes support bars 88 that can be provided to secure the glazing 68, metal face 54 or the like. The support bar 88 can also be used as a wall attachment to mount the solar heat collector 80 to the wall 26.
The support bars 88 are shown as longitudinal bars. Each support bar 88 has a C-shape cross-section and two opposite lugs 90 extending from the C-shape portion.
Other configurations of the support bar 88 may be possible.

[0043] Referring to Fig. 10, a solar heat exchanger unit 92 is shown in accordance with a particular embodiment. The solar heat exchanger unit 92 circulates the two streams of air 14, 16 in cross-flow relationship. That is, the outdoor air stream 14 flows in the solar heat collector 24 vertically (upward) through the solar heat exchanger unit 92 and the exhaust air stream 16 flows in the exhaust duct 40 horizontally through the solar heat exchanger unit 92. In this embodiment, the solar heat collector 24 includes the air channels 82 and the exhaust duct 40 includes an air plenum 94 defined between the wall 26 of the building 12 and the air channels 82 of the solar heat collector 24. The air plenum 94 has a contiguous portion with the air channels 82 such that the outdoor air stream 14 is in heat exchange relationship with the exhaust air stream 16. For example, the air plenum 94 and the air channels 82 are physically separated by a heat exchange boundary, e.g. a surface of the air channels, across which thermal energy can be transferred from air plenum to the air channels. The surface can be a metal surface or any other suitable surface.
The air plenum 94 is "airtight" with respect to the air channels 82. Stated differently, the exhaust air 16 in the air plenum 94 cannot enter the air channels 82. In an alternate embodiment, only the outdoor air 14 in the air channels 82 may enter the air plenum 94 by maintaining a higher pressure in the air channels 82 relative to a pressure in the air plenum 94, but the exhaust air 16 cannot enter the air channels 82.

[0044] The support bar 88 is mounted across the solar heat exchanger unit 92 on an intermediate section between opposite ends of the air channels 82. The support bar 88 offsets the glazing 68 from the air channels 82. In the embodiment shown in Fig. 10, the glazing 68 is a polycarbonate sheet. The glazing 68 is mounted on the support bar 88 through one or more brackets 96 or holding clips. Brackets 96 with arms 114 are also mounted along the air channels 82 to receive the screws 98 and avoid having screws extending through the air channels 82. The glazing 68 can be connected to the holding clip by any suitable means. The holding clip can be mounted on the support bar via screws 98 such that the screws 98 penetrate the holding clip and the C-shape portion of the support bar 88 and extend between the support bar 88 and the air channels 82 without piercing, cutting, penetrating and/or forming a hole in the air channels 82. In a particular embodiment, there is no air movement between the glazing 68 and the air channels 82.

[0045] Referring to Fig. 11, a solar heat exchanger unit 100 is shown in accordance with a particular embodiment. The solar heat exchanger unit 100 circulates the two streams of air 14, 16 in counter-flow relationship. The outdoor air stream 14 flows in the solar heat collector 24 vertically upward through the solar heat exchanger unit 100 and the exhaust air stream 16 flows in the exhaust duct 40 vertically downward through the solar heat exchanger unit 100. In this embodiment, the exhaust duct 40 includes the air channels 82 mounted to the wall 26 of the building 12 and the solar heat collector 24 duct includes an air plenum 102 defined between the air channels 82 and the sheet metal face 54. The air channels 82 can be mounted to the wall through the support bars 88.

[0046] In the embodiment shown in Fig. 11, the metal face 54 is corrugated and perforated to allow the outdoor air 14 to flow in the air plenum 102. The metal face 54 can be made from steel, aluminum, plastics and the like. The air plenum 102 can have a contiguous portion with the air channels 82 such that the outdoor air stream 14 is in heat exchange relationship with the exhaust air stream 16. For example, the air plenum 102 and the air channels 82 can be physically separated by a heat exchange boundary, e.g. a surface of the air channels 82, across which thermal energy can be transferred from air plenum 102 to the air channels 82. The surface can be a metal surface or any other suitable surface.

[0047] The air channels 82 are "airtight" with respect to the air plenum 102.
Stated differently, the exhaust indoor air 16 in the air channels 82 cannot enter the air plenum 102. In an alternate embodiment, that is, in a case of emergency or compromise, for example caused by an accident in renovation work, only the outdoor air 14 in the air plenum 102 may enter the air channels 82 by maintaining a higher pressure in the air plenum 102 relative to a pressure in the air channels 82, but the exhaust indoor air 16 cannot enter the air plenum 102.

[0048] The solar heat exchanger unit 100 includes a supporting bar 104 in the optional form of a Z-bar having a Z-shape cross-section mounted between the air channels 82 and the metal face 54. A limb 106 of the Z-bar is attached to the air channels 82 and an opposite limb 106 of the Z-bar is attached to the metal face 54.
The Z-bar offsets the metal face 54 from the air channels 82 to form the air plenum 102 and includes openings 108 to allow the outdoor air 14 to flow therethrough.
Brackets 96 with arms 114 are also mounted along the air channels 82 to receive the screws 98 and avoid having screws extending through the air channels 82.

[0049] Fig. 12 illustrates a section of the air system 10 in accordance to a particular embodiment. The solar heat collector 24 includes the air channels 82 which are provided within the exhaust duct 40 and the air channels 82 can carry the fresh outdoor air 14.

[0050] Fig. 13 illustrates a section of the air system 10 where the exhaust duct 40 includes the air channels 82 which are provided within the solar heat collector 24.
The air channels 82 carry the exhaust air 16.

[0051] Fig. 14 illustrates a section of the air channel 82 including three sub-channels 84. As mentioned above, the air channel 82 can include any other number of sub-channels 84 or cavities. The air channel 82 is shown connected to two brackets 96 or L-clips on opposite ends of the air channel 82 (also shown in Figs.
10-11). The L-clip is provided to mount and/or support the air channel 82 to an adjacent structure, such as walls of the solar heat collector 24 or the exhaust duct 40 as shown in Figs. 12-13. The term "L-clip" is intended to indicate the bracket 96 possessing a shape similar to the letter "L". In the embodiment shown in Fig.
14, the L-clip is fastened to the air channel 82 through a male/female interconnection or interlocking bracket 110. For example, the L-clip can be inserted by impact into a female hanger 112 of the air channel 82. This interconnection is used to avoid connections which can perforate the air channel 82, such as screws extending through the air channel 82. Any screws and/or bolts can be mounted on the L-clip instead of the air channel 82.

[0052] Fig. 15 illustrates an embodiment of the L-clip. The L-clip has an arm extending from a base 116 at a 90 degrees angle. The base 116 includes two parallel pins 118 which can be inserted into the corresponding hanger 112.

[0053] Fig. 16 illustrates a cross-section of the air channel 82 connected to the L-clip. The L-clip is shown with a screw 98 screwed into the arm 114. The screw can be used to install the air channel 82 to the adjacent structure or wall 26.

[0054] Fig. 17 illustrates a cross-section of air channels 82 connected in series. The L-clips are mounted on alternate face-to-back sides 120, 122 of adjacent air channels 82. Other configurations are within the scope of the present application.

[0055] Fig. 18 illustrates the air channels 82 mounted between the metal face 54 of the solar heat collector 24 and the wall 26. The air channels 82 are free from any screws, and the like, extending through the air channels 82 to avoid cross-contamination between the outdoor and indoor air streams 14, 16. The screws 98 can extend between the metal face 54 and the air channels 82.

[0056] Fig. 19 illustrates a cross-section of a solar heat exchanger unit 124 in accordance to a particular embodiment. The solar heat exchanger unit 124 includes the air channels 82 located in an air plenum 128 between the glazing 68 and the wall 26. Each air channel 82 has a single cavity and two opposite arms 114 to secure the air channel 82 within the air plenum 128. One arm 114 is secured to the glazing 68 with the screw 98 and the other arm 114 is secured to the wall 26 with another screw 98. The air channel 82 is free from screws 98 and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0057] Fig. 20 illustrates a cross-section of a solar heat exchanger unit 130 in accordance with another particular embodiment. Each air channel 82 includes three air cavities or sub-channels 84. The air channels 82 are connected to each other via the interlocking bracket 110. The air channel 82 is secured to the wall 26 by two brackets 96 with the L-clip type. A first air channel 82 has the bracket 96 on the face side 120 toward the glazing 68 and a second adjacent air channel 82 has the bracket 96 on the back side 122 toward the wall 26. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0058] Fig. 21 illustrates a cross-section of a solar heat exchanger unit 132 in accordance to another particular embodiment. The air channel 82 has an elliptical (e.g. circular) cross-section. Each air channel 82 has a single cavity and two opposite brackets 96 to secure the air channel 82 within the air plenum 128.
One bracket 96 is secured to the glazing 68 with a screw 98 and the other bracket 96 is secured to the wall with a screw 98. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0059] Fig. 22 illustrates a cross-section of a solar heat exchanger unit 134 in accordance to another particular embodiment. The air channel 82 has an octagonal cross-section. Each air channel 82 has a single cavity and two opposite arms 114 to secure the air channel 82 within the air plenum 128. One arm 114 is secured to the glazing 68 with a screw 98 and the other arm 114 is secured to the wall 26 with a screw 98. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0060] Fig. 23 illustrates a cross-section of a solar heat exchanger unit 136 in accordance to another particular embodiment. The air channel 82 has a triangular cross-section. Each air channel 82 has a single cavity and an arm 114 to secure the air channel 82 within the air plenum 128. The arm 114 also includes a seat 138 to receive a corner of an adjacent air channel 82. The arm 114 is secured to one of the glazing 68 and the wall 26 with a screw 98. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0061] Fig. 24 illustrates a cross-section of a solar heat exchanger unit 140 in accordance to another particular embodiment. Each air channel 82 includes nine air cavities 84. The air channels 82 are disconnected from each other. The air channel 82 has two brackets 96 on one side and two opposite brackets 96 on the other side to secure the air channel 82 within the air cavity 128. One two brackets 96 are secured to the glazing 68 with screws 98 and the two brackets 96 are secured to the wall 26 with screws 98. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0062] Fig. 25 illustrates a cross-section of a solar heat exchanger unit 142 in accordance to another particular embodiment. Each air channel 82 has a single cavity and two opposite interlocking brackets 110 to connect the air channel 82 with an adjacent air channel 82. A screw 98 is inserted through the glazing 68 and the interlocking bracket 110 to secure the air channel 82 to the glazing 68 and another screw 98 is inserted through the interlocking bracket 110 and the wall 26 to secure the air channel 82 to the wall 26. In an alternate embodiment, the air channel 82 can be secured to only one of the glazing 68 and the wall 26. The air channel 82 is free from screws and the like to maintain the air channel 82 airtight with respect to the air plenum 128.

[0063] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, the glazing and the metal face can be interchangeable. The air channel can have any suitable cross-section. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.

Claims

PCT/CA2018/051626

1. A solar air heating system comprising:
a solar heat collector extending between a first end and a second end, the solar heat collector having an inlet configured to receive fresh air and an outlet configured to discharge pre-heated air in a process or housing, the outlet disposed at the second end of the solar heat collector;
an exhaust duct extending between a first end and a second end, the exhaust duct configured to receive stale air from the process or housing and discharge the stale air outside the process or housing, the exhaust duct being fluidly sealed from the solar heat collector to avoid stale air from contaminating the fresh air; and a heat exchanger disposed between the solar heat collector and the exhaust duct with at least a portion of the solar heat collector in heat exchange relation with at least a portion of the exhaust duct, the heat exchanger disposed upstream of the outlet of the solar heat collector relative to a flow of the fresh air within the solar heat collector.

2. The solar air heating system of claim 1, wherein the heat exchanger is an air-to-air heat exchanger integrated into the solar heat collector to provide an additional heat source to pre-heat the fresh air while the fresh air flows through the solar air collector.

3. The solar air heating system of claim 1 or 2, wherein the solar heat collector and the exhaust duct are in heat exchange relationship along at least a physically overlapping portion of a length thereof.

4. The solar air heating system of any one of claims 1 to 3, wherein the solar heat collector comprises side-by-side air channels, limbs extending outwardly from an outer surface of the channels, and fastener extending through the limbs.

5. The solar air heating system of claim 4, wherein the limbs are provided on opposed front and back faces of the air channels.

6. The solar air heating system of claim 4 or 5, wherein the limbs are L-shaped.

7. The solar air heating system of any one of claims 1 to 3, wherein the solar heat collector comprises side-by-side air channels provided with integral mounting clips on an outer surface thereof, and wherein said integral mounting clips are engageable with corresponding brackets.

8. The solar air heating system of claim 7, wherein mounting clips and the brackets define a male/female interlocking engagement.

9. The solar air heating system of claim 7, wherein the brackets have a base and an arm extending from the base, and wherein a faster extends through the arm.

10. The solar air heating system of claim 4, wherein the fastener is engaged with a front cover of the solar heat collector, the front cover being spaced forwardly from a building wall, the building wall and the front cover defining a plenum, and wherein the side-by-side air channels being positioned in the plenum, an outer surface of the side-by-side air channels being exposed to the flow of stale air directed by the exhaust duct.

11. The solar air heating system of claim 4, wherein the plenum forms part of the exhaust duct.

12. A method for delivering heated fresh air inside a housing, the method comprising:
exhausting air from inside the housing to outside the housing;
heating fresh air located outside the housing through captured solar energy;
and while heating the fresh air with the captured solar energy, concurrently imparting thermal energy from the exhausted air to the fresh air through a heat exchange relationship between the exhausted air and the fresh air.

13. An air system for a building, comprising a solar air collector for pre-heating fresh outdoor air, the solar air collector having an outlet for discharging heated outdoor air inside the building; and an air-to-air heat exchanger integrated into the solar air collector to provide an additional heat source to pre-heat the fresh outdoor air while the fresh outdoor air flows through the solar air collector, the air-to-air heat exchanger defining an indoor air exhaust circuit having an inlet configured to be connected to an air exhaust line of the building and an outlet for venting indoor air from the building, the solar air collector defining an outdoor air inlet circuit fluidly isolated from the indoor air exhaust circuit to prevent mixing between the outdoor and indoor air streams, the outdoor air inlet circuit and the indoor air exhaust circuit having a heat exchange interface for allowing heat transfer between the outdoor air and indoor air streams upstream of the outlet of the solar air collector.

14. An air system for a building, comprising an indoor air exhaust circuit for venting air from inside the building; and an outdoor air inlet circuit for admitting outdoor air into the building, the outdoor air inlet circuit being fluidly isolated from the indoor air exhaust circuit, the indoor air exhaust circuit and the outdoor air inlet circuit being in heat exchange relationship along at least a physically overlapping portion of a length thereof, said outdoor air inlet circuit including a solar air collector within said physically overlapping portion to allow for combined solar and heat recovery heating within a single integrated unit.