CA2855142A1

CA2855142A1 - Convector for access floor environments

Info

Publication number: CA2855142A1
Application number: CA2855142A
Authority: CA
Inventors: Vince Derrick
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-06-25
Filing date: 2014-06-25
Publication date: 2015-12-25

Abstract

A heating and cooling system for use with an under-floor air delivery plenum, including a periphery-mounted heating/cooling module having separate internal chambers for receiving plenum air, heating recirculated room air, and mixing the two air streams for discharge into the room. Further including a booster fan unit and/or control valve and appropriate manifolds for operation in various configurations.

Description

CONVECTOR FOR ACCESS FLOOR ENVIRONMENTS
TECHNICAL FIELD
[001] The invention relates generally to systems for heating and cooling buildings, and to under-floor air delivery plenums for distributing conditioned air within buildings.
BACKGROUND OF THE INVENTION

[002] Under-floor air delivery plenums are an energy-efficient means of air distribution, popularly used in heating and cooling schemes for large spaces, particularly in office buildings. The system typically employs a raised floor having a plurality of floor tiles supported above a structural floor in abutting end to end fashion. The space between the floor tiles and the structural floor forms a plenum, through which conditioned (e.g. heated or cooled) air can be forced to circulate from a centrally located source.
Apertures and vents in the floor tiles permit the conditioned air to enter the room above the floor tiles.
Under-floor air delivery plenums are desirable because they permit widespread distribution of conditioned air throughout large spaces without extensive and complex ductwork. However, under-floor air delivery plenum systems typically have, inter alia, two problems: reduced air pressure at the periphery of the floor, caused by cumulative resistance along the flow path from the central pressure source; and, when used for heating, reduced heating effort at the periphery of the floor, caused by flow resistance and heat losses between the central heat source and the periphery. Auxiliary heating units are often installed near the periphery of the floor to mitigate the latter problem. Nonetheless, an improved system for efficiently delivering heated air to the periphery of the floor in an under-floor delivery environment is required.
SUMMARY

[003] In accordance with one aspect of the invention, there is disclosed a heating and cooling module (hereinafter "module") for use with an under-floor air delivery plenum (hereinafter "plenum") which increases the efficiency of the under-floor air delivery system. The module includes a housing having a bottom, an open top, opposite ends, opposite sides and an interior. A baffle divider is included which divides the interior into front, rear, and mixing chambers extending between the opposite ends, the front and rear chambers being continuous with the mixing chamber and the mixing chamber being continuous with the open top. The module further includes an elongated heating unit extending within the front chamber between the opposite ends.

[004] In another aspect, the module includes a front intake slot, which admits air into the front chamber from the room, for heating by the heating element; and a lower intake slot, which admits air into the rear chamber from the plenum, for mixing with the heated air in the mixing chamber.

[005] In another aspect, the aforementioned module forms part of a heating system further including a fan unit configured to draw air from the plenum and discharge air into the module's rear chamber, and/or a valve configured to control airflow from the plenum into the module.

[006] In another aspect, a heating and/or cooling system may employ multiple fan units, modules, valves, and ductwork or manifolds to suit the heating and/or cooling requirements of the space.

[007] In another aspect, the aforementioned module's heating element may be a liquid-carrying tube, configured to accept liquid within a range of 54-65 degrees Celsius.

[008] In another aspect, the lower intake slot of the heating modules is located proximate to the exterior wall of the room in which the heating module is positioned.

[009] With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the preferred typical embodiment of the principles of the present invention.
DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 shows a cross-section of a heating module of the invention, illustrating the internal configuration of the heating module and the principal air flow paths, according to an embodiment.

[0011] Figure 2 shows components of a system of the invention, illustrating in plan the layout of the system within a room, in accordance with an embodiment.

[0012] Figure 3 is a schematic illustration of an embodiment of the invention, showing air and heat flows between the various components.
DETAILED DESCRIPTION OF THE INVENTION

[0013] Figure 1 depicts in cross-section an embodiment of the invention, wherein a heating module is indicated generally by reference number 120. The heating module 120 is configured to supply heated air to a room 114, partly defined by an exterior wall 104. Within the room 114, a structural floor 102 and a raised access floor 110 enclose between them an air delivery plenum 112 (hereinafter "plenum" 112). A
booster fan unit 144 may be mounted within the plenum. The booster fan unit 144 supplies air from the plenum 112 to the heating module 120 by way of a duct 146 passing through a slot 140 in the raised access floor 110.

[0014] A valve 148 may be positioned upstream or downstream of the booster fan unit 144, and be configured to control the air supply to the heating module 120. When the heating module 120 is in operation, the valve 148 may be in an open configuration that permits an air supply to the heating module 120. When the heating module 120 is not in operation, the valve 148 may be in a closed configuration that substantially blocks the air supply to the heating module 120. The heating module 120 may contain three distinct chambers, defined herein by their locations within the module 120. In one embodiment, the rear chamber 136 receives air from the booster fan unit 144 by way of the lower intake slot 140, and discharges said air into the mixing chamber 138. The front chamber 134 may receive air from the room 114 by way of an open front intake slot 130, and discharge the air into the mixing chamber 138. The mixing chamber 138 may receive air from both the front chamber 134 and rear chamber 136, allowing the two air streams to mix, and discharge the mixed air into the room 114 by way of an open top vent 128.

[0015] A front wall 122, a rear wall 124, and a bottom 126 further define the heating module's enclosure.
End walls, not shown in cross-section, close the ends of the heating module's enclosure.

[0016] During operation, a heating element 142, located within the front chamber 134, heats the air therein. The heating process may produce a convective flow of air through the heating module 120.
Thereby, heated air from the front chamber 134 rises into the mixing chamber 138, while unheated air is drawn into the front chamber 134 via the front intake slot 130.

[0017] The heating element 142 may use any working medium including, but not limited to, hot water and/or electric current (i.e. it may be a liquid radiator, an electric resistance heater, or other suitable heat source). The heating element 142 may have fins 143 to increase the efficiency of convective heat transfer to the air by increasing the surface area of the heating element 142 with which the air may interact.

[0018] A baffle divider 132 may separate the front chamber 134 from the rear chamber 136. In some embodiments, the baffle divider 132 may extend from the bottom 126 of the enclosure to above the heating element 142, and may ensure that the air stream received through the front intake slot 130 passes the heating element 142 prior to mixing with the separate air stream received through the lower intake slot 140.

[0019] The heating module 120 (220) may be of any length. In some embodiments, any of the front chamber 134, rear chamber 136, mixing chamber 138, baffle divider 132, and heating element 142 may extend the entire length of the heating module between the opposite end walls (not shown in cross-section).

[0020] In some embodiments, the front intake slot 130 and lower intake slot 140 may be of any length, not exceeding the overall length of the heating module 120 (220).

[0021] In some embodiments, any of the front chamber 134, rear chamber 136, and mixing chamber 138 may contain vanes or other devices to control and/or distribute the airflow therein.

[0022] In some embodiments, the top vent 128 may be of any length. Said top vent may be completely open, or may comprise a grille, louver, safety barrier, or air-flow direction device.

[0023] Figure 2 depicts in plan one embodiment of a system 200 of the present invention, used for heating a room 214. In some embodiments the room 214 may have an exterior wall 204 and a raised access floor 210 (shown in cut-away) enclosing an air delivery plenum 212 (hereinafter "plenum" 212) located thereunder.

[0024] A booster fan unit 244, located within the plenum 212, receives air from the plenum and delivers the air to an air manifold 246.

[0025] The air manifold 246 divides the stream of received air and distributes air to a plurality of heating modules 220. In some embodiments, typically wherein the room 214 is relatively large, the system 200 may include multiple heating modules 220, receiving air from a single air manifold 246 (as shown), or from multiple air manifolds 246, or from multiple booster fan units 244 without air manifolds, or directly from a plenum 212 without booster fan units. In some other embodiments, typically wherein the room 214 is relatively small, the system 200 may include a single heating module 220, receiving air from a single air manifold 246, or from a single booster fan unit 244 without an air manifold, or directly from a plenum 212 without a booster fan unit.

[0026] One or more of the heating modules 220 may be located proximate to the exterior wall 204.

[0027] In some embodiments, the air manifold 246 may include vanes, dampers, variances of cross-sectional area, or other devices to control the airflow therein.

[0028] In some embodiments, one or more valve units 248 may be used to control the flow of air within the heating system. The valve unit(s) 248 may be located upstream of the booster fan unit (as shown), downstream of the booster fan unit, immediately upstream of the heating module 220, or in any other suitable location. The valve unit 248 may be configured to operate between a closed state in which the heating modules 220 are substantially blocked from receiving air, and an open state in which the heating modules 220 receive air. In some embodiments that include more than one heating module 220, multiple valve units 248 may be located and independently controlled so that some heating modules 220 may receive air, while simultaneously other heating modules 220 may be substantially blocked from receiving air.

[0029] A heating loop 250 may supply heat to the various heating modules 220.
In some embodiments, the heating loop 250 may include a heat source 252, a supply conduit 254 having one or more branches, and a return conduit 256 having one or more branches. In some embodiments, the heating loop 250 may include various devices for varying the heat energy delivered to individual heating modules 220, or to groups of heating modules.

[0030] In some embodiments, the heating loop 250 may employ electric current, supplied by a local power unit 252, external power supply, or other power source. In some other embodiments, the heating loop 250 may employ hot water, steam, or other liquid heat transfer medium, supplied by a local heater or boiler 252 or other external source. In some embodiments, the heating loop 250 may employ a condensing boiler 252 delivering liquid within a range of 54-65 degree Celsius to the heating modules 220.

[0031] In some embodiments, a plurality of diffusers 260 may supply air from the plenum directly to the room 214. These diffusers 260 may be located at least 2 metres distant from an exterior wall 204.

[0032] The general scale and proportions shown in Figure 1 and Figure 2 are for illustrative purposes only. In some embodiments, the heating module may have an elongated shape as illustrated by the heating modules 220 of Figure 2.

[0033] In Figure 3, a block diagram of a system of one embodiment of the invention, indicated generally by numeral 300, depicts the flows of air and heat energy therein during operation. As illustrated, a booster fan unit 344 supplies pressurized air from a plenum 312 to a heating module 320 having a front chamber 334, a rear chamber 336, a mixing chamber 338, and a heating element 342. The heating module 320 supplies heated air to a room 314, and receives air from the room for reheating and recirculation.

[0034] Air from a plenum 312 flows (372) into a booster fan unit 344. In some embodiments, this air may pass through an intake port or valve between the plenum 312 and the booster fan unit 344.

[0035] The booster fan unit 344 pressurizes the air to a pressure greater than that of the room 314, whereafter the air flows (374) into the rear chamber 336 of the heating module 320. In some embodiments, this air may pass through a duct, manifold, valve, or intake slot between the booster fan unit 344 and the rear chamber 336.

[0036] In some embodiments, the air flow 372 from the plenum 312 may be induced by the intake suction of the booster fan unit 344. In some other embodiments, an external air supply unit (not shown) may be used to pressurize the air within the plenum to a pressure greater than that of the room 314, causing the air to flow along a path, defined by arrows 372-374-376-380, toward the room 314, without a booster fan unit.

[0037] In some embodiments, a booster fan unit 344 may supply air directly from the room 314 to the rear chamber 336 of the heating module 320, without a plenum.

[0038] Air from the rear chamber 336 flows (376) into the mixing chamber 338 due to the elevated pressure in the rear chamber 336 with respect to the room 314.

[0039] A heating loop 350-352-342-354 supplies energy 352 from a power source 350 to the heating module's heating element 342. Heat energy is transferred by convection (390) from the heating element 342 to air in the front chamber 334.

[0040] Heated air from the front chamber 334 flows (378) into the mixing chamber 338 due to buoyancy and to the suction of the air flow 376 from the rear chamber 336.

[0041] In the mixing chamber 338, air received from the front chamber 334 mixes with air received from the rear chamber 336.

[0042] Air from the mixing chamber 338 flows (380) into the room 314. In some embodiments, this air may pass through a grille or louver between the mixing chamber 338 and the room 314.

[0043] In some embodiments exemplified by Figure 4, operation of the invention may produce a temperature profile depicted in Figure 4, in the heating module and its surroundings.

[0044] Air from the room 314 flows (382) into the front chamber 334 due to convective draught. In some embodiments, this air may pass through an intake slot, grille, or louver between the room 314 and the front chamber 334.

[0045] Although the inventions have been described in terms of certain preferred embodiments, other embodiments will be apparent to those of ordinary skilled in the art, including embodiments that do not include all of the features and benefits set forth herein. Accordingly, the invention is defined only by the appended claims. Any manner of software designs, architectures or programming languages can be used in order to implement embodiments of the invention. Components of the invention may be implemented in distributed, cloud-based, and/or web-based manners.

[0046] Conditional language used herein, such as, among others, "can,"
"might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment.

Claims

What is claimed is:
1. A heating module for use with an under-floor air delivery plenum within a building, said module comprising:
a housing having an interior defined by opposite end walls, opposite front and rear walls, a bottom, and a top;
the top comprising a vent for expelling heated air from the interior;
the bottom located adjacent to the floor and parallel to the floor;
the front wall discontinuous with the bottom, thereby forming a front intake slot for receiving air from a space above the floor;
a baffle divider extending between the opposite end walls and extending to the bottom, dividing the interior into front and rear chambers, the front chamber being continuous with the open front intake slot;
a heating element within the front chamber, for heating the air in the front chamber by convection;
a mixing chamber above the baffle divider, continuous with the front and rear chambers and the top vent, for receiving air from the front and rear chambers for mixing therein;
a lower intake slot through the bottom, continuous with the rear chamber, the rear chamber being thereby configured to receive air through said lower intake slot and then discharge said air into the mixing chamber;
wherein a portion of the air within the mixing chamber is discharged via the top vent.
2. The heating module of claim 1, wherein the heating element extends substantially between the opposite end walls.
3. The heating module of claim 2 further comprising a plurality of fins affixed to the exterior surface of the heating element, in thermal communication therewith, and oriented substantially perpendicular thereto.
4. The heating module of claim 3, wherein the heating element comprises a tube configured to receive liquid through at least one inlet, and discharge said liquid through at least one outlet.
5. The heating module of claim 4, wherein the heating element is configured to receive, via its inlet, liquid within a range of 54-65 degrees Celsius from an external heat source, and discharge said liquid via its outlet.
6. The heating module of claims 2, wherein the heating element comprises an electric resistance heater.

7. A building heating and cooling system, the system comprising:
At least one heating module for use with an under-floor air delivery plenum within a building, said module comprising:
a housing having an interior defined by opposite end walls, opposite front and rear walls, a bottom, and a top;
said top comprising a vent for expelling heated air from the interior;
said bottom located adjacent to the floor and parallel to the floor;
said front wall discontinuous with said bottom, thereby forming a front intake slot for receiving air from a space above the floor;
a baffle divider extending between the opposite end walls and extending to the bottom, dividing the interior into front and rear chambers, said front chamber being continuous with the open front intake slot;
a mixing chamber above said baffle divider, continuous with the front and rear chambers and the top vent, for receiving air from said front and rear chambers for mixing therein;
a lower intake slot through the bottom, continuous with the rear chamber, said rear chamber being thereby configured to receive air via said lower intake slot and then discharge said air into the mixing chamber;
a heating element within the front chamber for heating the air in the front chamber by convection;
wherein a portion of the air within the mixing chamber is discharged via the top vent.
8. The system of claim 7, wherein the lower intake slot is continuous with the under-floor air delivery plenum, the rear chamber being thereby configured to receive air from said plenum through the lower intake slot and then discharge said air into the mixing chamber.
9. The system of claim 8, further comprising a valve unit configured to operate between a closed state in which the lower intake slot is substantially blocked from receiving air from the plenum, and an open state in which the lower intake slot receives air from the plenum.
10. The system of claim 7, further comprising:
at least one booster fan unit, located within the under-floor air delivery plenum, for pressurizing the air therein;
said booster fan unit being in fluid communication, via a duct passing through the floor, with the lower intake slot of a single heating module;
the rear chamber of the heating module being thereby configured to receive air from the booster fan unit through the lower intake slot and then discharge said air into the mixing chamber.

11. The system of claim 7, further comprising:
at least one air manifold comprising a duct having at least one input port and a plurality of output ports;
at least one booster fan unit, located within the under-floor air delivery plenum, for pressurizing the air therein;
said booster fan unit being connected to, and in fluid communication with, an input port of a single air manifold;
each outlet port of said air manifold being continuous, through the floor, with the lower intake slot of a single heating module;
the rear chambers of a plurality of heating modules being thereby configured to receive air from each booster fan unit through their lower intake slots and then discharge said air into their mixing chambers.
12. The system of claim 7 having a plurality of heating modules and booster fan units.
14. The system of claim 10, wherein the booster fan unit further comprising a valve for controlling the air travelling through the heating and cooling module, said valve being configured to operate between a closed state in which the lower intake slot is substantially blocked from receiving air from the plenum, and an open state in which the lower intake slot receives air from the plenum.
15. The system of claim 14, further comprising an external heating loop configured to deliver liquid within a temperature range of 54-65 degrees Celsius to the inlet of the heating element, and to receive liquid from the outlet of said heating element.
16. The system of claim 10 further comprising:
At least one diffuser, aperture, vent, or other suitable structure or device for receiving air from the under-floor air delivery plenum and discharging it into a space above the floor;
said structure or device located at least 2 meters distant from the building's outer wall.
17. The system of 16, wherein the lower intake slot of each heating module is located proximate to the building's outer wall.