VENTILATION SYSTEM

Abstract

The present invention is directed to a 360 degree ventilation system with a single unitary plenum. The present invention is also directed to a 360 degree ventilation system with a single mixing chamber extending at least substantially entirely around the perimeter of the blow ventilation system. The present invention is also directed to a 360 degree ventilation system with a heating/cooling units that extend substantially all the way around the perimeter of the ventilation system. The present invention is also directed to a 360 degree ventilation system with a single return air chamber.

Description

RELATED APPLICATION

The present application claims priority to U.S. provisional patent application No. 61/045,462, filed on Apr. 16, 2008; all of the foregoing patent-related document(s) are hereby incorporated by reference herein in their respective entirety(ies).

FIELD OF THE INVENTION

The The present invention relates to ventilation systems and more particularly a four way blow ventilation systems located between a drop ceiling and a structural ceiling of a building.

DESCRIPTION OF THE RELATED ART

FIGS. 1a and 1b show a conventional four way blow ventilation system 100 for installation and use between a drop ceiling and a structural ceiling of a building. System 100 includes four separate induction units 102a, 102b, 102c, 10d. Each induction unit includes: a plenum 104; a heating/cooling unit 106; a drainage base 107; a mixing chamber outer wall 109; and nozzles 116. The induction unit mixes return air (shown by arrow R) from the building with primary air (shown by arrows P) from a primary air source (not shown) and returns mixed air (shown by arrows M to the room.

More specifically, primary air, which is usually cleaned and may be thermally conditioned, is provided under pressure through primary air conduits (not shown) in the direction of arrows P to each of the four separate plenums 104a, 104b, 104c, 104d as shown in FIG. 1a. The pressure of the primary air in the plenums forces it through venturi nozzles 116 in the bottom wall of each plenum as shown in FIG. 1b. Meanwhile, return air travels in the direction of arrow R through each heating/cooling unit 106 as shown in FIG. 1b. To explain this air flow pattern a bit, air currents caused by the flow of the primary air at the outlets of the venturi nozzles effectively suck return air up from the volume of the room under the ceiling directly under system 100 and through the return air intake unit to the vicinity of the outlets of the venturi nozzles. The return air may be heated or chilled by the heating cooling units as it passes through under the influence of the pressure gradient caused by the primary air output by the venturi nozzles.

Each induction unit 102a,b,c,d defines a mixing chamber 108a,b,c,d. More specifically, in system 100, this mixing chamber (see DEFINITIONS section) is defined by: mixing chamber outer wall 109a,b,c,d and the drainage base 107. Although not shown for the sake of clarity of illustration, four way blow systems will generally include a grille that provides an inner wall for the mixing chamber below the heating/cooling unit. In the mixing chambers 108a,b,c,d, the return air R and the primary air P mix to form mixed air M. By the pressure of the primary air output by the venturi nozzles, the mixed air M is driven downwards and out of each induction unit, in the direction of the arrow M. Of course, the mixed air is generally cleaner than the ambient air in the room because of the use of clean primary air—this is generally one of the main purposes of having a ventilation system. The mixed air will also generally be heated or cooled relative to the air in the room because of thermal conditioning of the primary air and/or heating or cooling of the heating/cooling units—this is generally another main purpose of having a ventilation system.

In a four way blow ventilation system, the four units are generally suspended or supported over a drop ceiling so that the lower surfaces of the induction unit, and apertures 118, are more or less even with the drop ceiling. As mentioned above, conventional four way blow ventilation systems usually have a grill. This grille usually includes louvers at the location where the mixed air M leaves each induction unit. The louvers are oriented to direct the mixed air output by the ventilation system peripherally away from each induction unit. This forms an air pattern in the room where: (i) mixed air clings to the ceiling as it travels out in four directions away from the four way blow system; (ii) mixed air gradually drops into the volume of the room when it is away from the volume under the four way blow system; and (iii) return air from directly under the four way blow system rises up into the four way blow system. This is an advantageous air flow pattern in that it allows a relatively large quantity of air to circulate without causing noticeable drafts, and can promote in relatively uniform temperature distribution over the volume of a room. Generally speaking, a room may include more than one four way blow system in its ceiling, with the number and spacing of four way blow ventilation systems being professionally determine based on the characteristics of the room, the desired air quality or conditioning, the specifications of the four way blow systems and/or other conventionally understood factors.

U.S. Pat. No. 6,623,353 (“Akhtar”) shows an example of a four way blow ventilation system with four separate induction units. U.S. Pat. No. 6,569,010 (“Miller”) discloses an air handling system.

Description Of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications (for example, published patents) are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section, they are all hereby incorporated by reference into this document in their respective entirety(ies).

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a 360 degree blow induction system with a single unitary plenum. The present invention is also directed to a 360 degree blow ventilation system with a single mixing chamber extending at least substantially entirely around the perimeter of the 360 degree blow ventilation system. The present invention is also directed to a 360 degree blow ventilation system with a single heating/cooling unit (see DEFINITIONS section) extending at least substantially entirely around the perimeter of the 360 degree blow ventilation system.

Various embodiments of the present invention may exhibit one or more of the following objects, features and/or advantages:

(1) improved air distribution within the unitary plenum;

(2) improved air distribution over the set of venturi nozzles between the plenum and the air mixing chamber;

(3) improved air distribution within the unitary air mixing chamber;

(4) because the unitary plenum and unitary air mixing chamber extend all the way around (including over any corner space), there is room for more nozzles within a given footprint;

(5) decrease in plenum volume;

(6) increased flexibility in dimensioning the unit to fit in a required space and still provide a required airflow (for example, trading off the vertical dimension against foot print size);

(7) greater area available to receive return air from the room;

(8) greater volume available for thermal treatment devices for the return air within the volume of the mixing chamber;

(9) improved air flow rate, improved air flow per unit of foot print area and improved air flow per unit of device volume;

(10) decreased installation costs; and/or

(11) decreased materials costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:

FIG. 1a is an orthographic top view of a prior art four way blow ventilation system;

FIG. 1b is an orthographic top view of a prior art four way blow ventilation system;

FIG. 2 is a front orthographic view of a first embodiment of a 360 degree blow ventilation system according to the present invention;

FIG. 3 is a side orthographic view of the first embodiment system;

FIG. 4 is a bottom orthographic view of the first embodiment system;

FIG. 5 is a perspective view of the top and sides of the first embodiment system; and

FIG. 6 is a perspective view of the top and sides of the first embodiment system.

FIG. 7 is a perspective view of a drainage base sub-assembly of the first embodiment system;

FIG. 8 is a simplified perspective view of a heating/cooling unit in the first embodiment system;

FIG. 9 is a perspective view of a plenum top sub-assembly of the first embodiment system;

FIG. 10 is a perspective view of the first embodiment system with the drainage base sub-assembly removed;

FIG. 11 is an orthographic bottom view of nozzle plate component of the first embodiment system;

FIG. 12 is an orthographic bottom view of a venturi nozzle component of the first embodiment system;

FIG. 13 is an orthographic side view of a venturi nozzle component of the first embodiment system;

FIG. 14 is an orthographic bottom view of the first embodiment system;

FIG. 15 is an orthographic top view of the first embodiment system;

FIG. 16 is an orthographic side view of the first embodiment system;

FIG. 17 is an orthographic front view of the first embodiment system;

FIG. 18 is a perspective view of the first embodiment system;

FIG. 19 is an orthographic front view of a second embodiment of a ventilation system according to the present invention;

FIG. 20 is an orthographic side view of the second embodiment system;

FIG. 21 is an orthographic top view of the second embodiment system;

FIG. 22 is a perspective view of the second embodiment system;

FIG. 23a is an orthographic bottom view of a third embodiment of a ventilation system according to the present invention;

FIG. 23b is a cross-sectional orthographic side view of the third embodiment system;

FIG. 24 is an orthographic bottom view of a fourth embodiment of a ventilation system according to the present invention;

FIG. 25 is a cross-sectional orthographic side view of the fourth embodiment system; and

FIG. 26 is a cross-sectional orthographic side view of a grille component of the fourth embodiment system.

DETAILED DESCRIPTION OF THE INVENTION

Discussion will begin with a couple of simplified, not necessarily preferred embodiments of the present invention (shown in FIGS. 23-26) to illustrate some of the inventive concepts. Discussion will then proceed to a couple of preferred embodiments (shown in FIGS. 2 to 22).

FIGS. 23a and 23b show ventilation system 400 according to the present invention, including: unitary plenum portion 404; heating/cooling unit 406; drainage base 407; mixing chamber outer wall 409; and venturi nozzles 416. Primary air P is blown into the unitary plenum portion from a primary air source (see DEFINITIONS section). The primary air is then forced through the nozzles 416 and down into the mixing chamber 406. Although only two nozzles are shown in FIGS. 23a and 23b, it is highly preferred that more nozzles be provided so that one or more rows of nozzles extend at least substantially all the way around the perimeter of system 400. In this embodiment, the mixing chamber is defined by the mixing chamber outer wall 409 and drainage base 407. In this embodiment, the drainage base includes inner mixing chamber wall 420 to help define the mixing chamber and to isolate the mixed air path M from the return air path R. Alternatively, this inner mixing chamber wall could be provided on a grille component, provided as a separate piece part, even omitted altogether.

Importantly and in distinction from the four way blow ventilation system discussed above in connection with FIGS. 1a and 1b, the mixing chamber extends all the way around the perimeter of system 400. In mixing chamber 408, the primary air sucks in and mixes with return air R from the room to form mixed air M. Return air R passes through the heating/cooling unit 406, and may therefore be heated or cooled just before it reaches mixing chamber 408. Mixed air M is forced down and out of mixing chamber 408, as shown by arrows M, by primary air P being continuously blown in by venturi nozzles 416. Because the mixing chamber extends all the way around the perimeter, mixed air M is blown out all the way around the perimeter. This: (i) improves air distribution in the room; (ii) allows a greater volume of air to be output from a given ventilation system footprint; (iii) can allow the footprint to be made small for given performance requirements; and/or (iv) reduces the possibility that occupants of the room will feel a draught from mixed air M being blown out of the ventilation system.

The heating/cooling unit is preferably in the form of coils made of pipes carrying heated or chilled water, but other types of heating/cooling units may be used with the present invention, such as electric heating coils. Some embodiments of the present invention may omit the heating/cooling unit altogether, but this is not necessarily preferred because it decreases the opportunity to do thermal conditioning of the mixed air output by the ventilation system. Additionally or alternatively, other air treatment components, such as ionizers could be placed at the location of heating/cooling unit 406 and/or elsewhere in the ventilation system.

Drainage base 407, in addition to providing the inner mixing chamber wall discussed above, also catches condensed moisture that falls from the heating/cooling unit. This moisture is drained from system 400 by any conventional means (not shown).

FIGS. 24 to 26 show ventilation system 500 according to the present invention, including: unitary plenum portion 504; heating/cooling unit 506; nozzles 516; and grille 522. As shown in FIG. 26, grille 522 includes central return air grille 505; louvers 524 and drainage chamber 526. As shown in FIG. 24, louvers 524 direct mixed air peripherally outward all the way around perimeter of system 500. These louvers extend all the way around the perimeter (even in the corners) because: (i) the mixing chamber and nozzles extend all the way around the perimeter; (ii) mixed air is created all the way around the perimeter; and (iii) outputting air all the way around the perimeter provides better air and temperature distribution with less potential for draughts. Alternatively, the louvers may not extend continuously around the corners in order to simplify the construction of the louvers, which may be especially helpful if the louvers are positionally adjustable. As best seen in FIG. 24, the opening at the center of grille 522 is a very narrow rectangle. It is noted that this: (i) helps show the full scope of the invention; but (ii) is not necessarily preferred because it may not provide an optimally sized or shaped footprint for return air R being sucked up from the room through this opening.

FIGS. 2 to 18 show ventilation system 200 according to the present invention. System 200 includes: plenum intake conduit 203; unitary plenum 204; heating/cooling unit 206 (this unit 206 is shown in many of the Figures without surface detail for the sake of clarity of illustration) outer mixing chamber wall 209; nozzles 216; corner supports 232; drainage base 234; support brackets 250; nozzle plate 252; and hanger bracket 256. System 200 is preferably placed so that its bottom plane is more or less even with a drop ceiling of a room in a building. Generally, a grille (not shown) is placed over this bottom plane and affixed to it. Preferably this grille includes an inner air mixing chamber wall and louvers as explained above in connection with system 500 a central return air grille.

System 200 mixes primary air and return air to form mixed air, as discussed above in connection with prior art system 100. Primary air is fed under pressure from a primary air source (not shown) into the plenum intake conduit and through central aperture 205 (see FIG. 5) into the unitary plenum. The unitary plenum is a single chamber that extends over substantially the entire footprint of the ventilation system 200. As shown in FIGS. 4, 10, 11 and 14, nozzle plate 252 forms the bottom surface of the unitary plenum. Nozzle plate 252 has a plurality of nozzle apertures 214 sized to accommodate venturi nozzles. As shown in FIG. 11, some preferred dimensions (in inches unless otherwise specified) for the nozzle plate of this system 200 embodiment are as follows: D1=35.93; D2=16.25; D3=2.75; D4=3.69; D5=3.94; D6=0.81; D7=3.69; D8=0.81; D9=1.63; D10=3.94; D11=1.38; D12=16.25; D13=3.94; D14=35.93; D15=3.69; D16=4.00; D17=3.00; D18=CLS-0616-1 PEM; D19=CLSS -032-1 PEM; D20=3.00; D21=4.00; D22=3.94. The nozzle plate preferably includes a lip around its outer perimeter to facilitate attachment to the rest of system 200.

While generally similar to the prior art system 100, these venturi nozzles in system 200 can extend all the way into the corners of the footprint of the ventilation system. That means greater primary airflow can be accommodated in a given footprint and that this primary airflow is more evenly distributed around the perimeter of the footprint.

The air mixing chamber 208 is also unitary and extends all the way around the perimeter of system 200. As shown in FIGS. 4, 6 and 10, in this preferred embodiment, mixing chamber 208 is defined by inner mixing chamber wall portion 237 of drainage base 234, outer mixing chamber wall 209 and nozzle plate 252. The space between drainage base 234 and nozzle plate 252 defines a third unitary space (sometimes called an air return chamber) to accommodate heating/cooling unit 206.

Heating/cooling unit 206 and/or any outer peripheral wall of the air return chamber must allow return air to be sucked through it into the mixing chamber. For example, with a heating/cooling unit made up of a matrix of pipes, as shown in FIG. 10, sufficient space must be left between the pipes to allow return air to be sucked through the heating/cooling unit at a sufficient volumetric rate. The unitary air mixing space is located below and around the venturi nozzles (shown in FIGS. 12 and 13). Because heating/cooling unit 206 extends all the way around the perimeter of system 200, a large volumetric flow of return air, relative to the size of the footprint of system 200 is thermally conditioned by the heating/cooling unit. Because air mixing chamber 208 extends around the entire perimeter of system 200 (even around the corner spaces), a large volumetric flow of mixed air air, relative to the size of the footprint of system 200 is output by the ventilation system. FIGS. 13 and 14 show, at reference numeral 260 how the nozzles, and the air mixing chambers below it, extend into corner areas which are unused in prior art four way blow ventilation systems.

After passing through any thermal conditioning device(s), the return air is drawn by, and mixes with the primary air from the venturi nozzles in air mixing chamber 208 (that is located below the venturi nozzles) to form mixed air. This mixed air is driven out of the bottom side of the unitary air mixing chamber, preferably through louvers in the bottom grille (not shown) that are oriented to direct output mixed air peripherally outwards, at least substantially all the way around the perimeter of system 200. The direction of the flow of mixed air out of the ventilation system is shown by arrows M in FIGS. 2 and 3. Because the air mixing chamber is unitary, air can mix and mixed air can pass out of the ventilation system 200 and into the room in the corner regions, as shown by arrow M in FIG. 6.

As shown in FIGS. 10 and 18, coil holes 262 allow the pipes of heating/cooling unit 206 to get through outer air mixing chamber wall 209. In this embodiment, there are four holes 262 for: (i) hot water supply; (ii) cold water supply; (iii) hot water return; and (iv) cold water return. As shown in FIG. 7, drainage base 334 includes notch 235 to accommodate the pipes of heating/cooling unit 206. As shown in FIGS. 7 and 14, drainage base 234 also includes drain hole 258 to allow drainage of collected condensation from heating/cooling unit 206. As shown in FIGS. 14, 15 and 18; a transition piece 254 is preferably used with system 200 to get primary air from a round duct into the rectangular opening of the unitary plenum.

As shown in FIG. 14, hanger bracket 256 is used to mechanically connect system 200 to the structural ceiling of a room or building.

As shown in FIG. 10, support brackets 250 are used to suspend the pipes of heating/cooling unit from nozzle plate 252.

FIGS. 15 to 18 show some preferred dimensions (in inches unless otherwise specified) for use in ventilation system 200 as follows: D23=46.45; D24=36.07; D25=25.00; D26=36.14; D27=14.00; D28=diameter 8.00; D29=17.80; D30=½ FPT hot water return; D31=4.25; D32=¾ FPT cold water return; D33=½ FPT hot water supply; D34=2.50; D35=¾ cold water return; D36=13.75; D37=4.00; D38=36.00; D39=13.75; D40=17.80; D61=¾ PVC drain connection; and D62=diameter 8.

FIGS. 19 to 22 show ventilating system 300 according to the present invention. In many respects, system 300 is similar to system 200, but it is smaller. Some preferred dimensions (in inches unless otherwise specified) are as follows: D41=21.06; D42=5.74; D43=13.11; D44=21.14; D45=6.07; D46=½ FPT hot water return; D47=½ cold water return 21.14; D48=3.00; D49=1.54; D50=10.02; D51=1.50; D52=½ FPT cold water supply; D53=½ FPT hot water supply; D54=3.50; D55=¾ PVC drain; D56=2.07; D57=21.11; and D58=21.07.

DEFINITIONS

The following definitions are provided to facilitate claim interpretation and claim construction:

Present invention: means at least some embodiments of the present invention; references to various feature(s) of the “present invention” throughout this document do not mean that all claimed embodiments or methods include the referenced feature(s).

First, second, third, etc. (“ordinals”): Unless otherwise noted, ordinals only serve to distinguish or identify (e.g., various members of a group); the mere use of ordinals implies neither a consecutive numerical limit nor a serial limitation.

Mechanically connected: Includes both direct mechanical connections, and indirect mechanical connections made through intermediate components; includes rigid mechanical connections as well as mechanical connection that allows for relative motion between the mechanically connected components; includes, but is not limited, to welded connections, solder connections, connections by fasteners (for example, nails, bolts, screws, nuts, hook-and-loop fasteners, knots, rivets, force fit connections, friction fit connections, connections secured by engagement added by gravitational forces, quick-release connections, pivoting or rotatable connections, slidable mechanical connections, latches and/or magnetic connections).

Chamber: a chamber shall be considered as a chamber even if it is not fully enclosed by solid walls and/or leaks some air, so long as it effectively acts substantially like a chamber with respect to directing airflows.

At least substantially around: any gaps must be less than the gaps typical of a similarly sized four way blow ventilation system.

Heating/cooling unit: a device that can heat air, cool air or both; may be made up of multiple physically separate sub-units; heating/cooling units are not necessarily limited with respect to source of power and/or heating cooling mechanism or medium.

Primary air: air from a source other than the space being ventilated, not necessarily limited with respect to: air quality and/or thermal conditioning.

To the extent that the definitions provided above are consistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall be considered supplemental in nature. To the extent that the definitions provided above are inconsistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall control. If the definitions provided above are broader than the ordinary, plain, and accustomed meanings in some aspect, then the above definitions shall be considered to broaden the claim accordingly.

To the extent that a patentee may act as its own lexicographer under applicable law, it is hereby further directed that all words appearing in the claims section, except for the above-defined words, shall take on their ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), and shall not be considered to be specially defined in this specification. In the situation where a word or term used in the claims has more than one alternative ordinary, plain and accustomed meaning, the broadest definition that is consistent with technological feasibility and not directly inconsistent with the specification shall control.

Unless otherwise explicitly provided in the claim language, steps in method steps or process claims need only be performed in the same time order as the order the steps are recited in the claim only to the extent that impossibility or extreme feasibility problems dictate that the recited step order (or portion of the recited step order) be used. This broad interpretation with respect to step order is to be used regardless of whether the alternative time ordering(s) of the claimed steps is particularly mentioned or discussed in this document.

Claims

1. A ventilation system comprising:

a plenum assembly comprising: an inlet aperture sized, shaped and located to receive primary air from a primary air source, a plurality of walls defining a unitary interior volume of the plenum, the plurality of walls comprising a bottom wall defining a central axis of the ventilation system, and angular and radial directions with respect to the central axis, and a plurality of outlet apertures defined in bottom wall; and

an air mixing chamber in fluid type communication with the plenum assembly through the plurality of outlet apertures, with the air mixing chamber extending at least substantially around the angular direction.

2. The system of claim 1 further comprising a return air chamber sized and located to receive a heating/cooling unit, with the return air chamber being radially inwards of the air mixing chamber and extending at least substantially around the angular direction.

3. The system of claim 2 further comprising a heating cooling unit located at least substantially within the return air chamber.

4. The system of claim 1 wherein the plenum assembly further comprises a plurality of nozzles respectively located in the outlet apertures.

5. The system of claim 4 wherein the plurality of nozzles are venturi nozzles.

6. The system of claim 1 wherein the bottom wall of the plenum is at least substantially quadrangular whereby it has four sides.

7. The system of claim 6 wherein the plurality of walls further comprises a four sided peripheral wall extending from the four sides of the bottom wall.

8. The system of claim 7 wherein:

the plurality of walls has a top wall extending between the four sides of the peripheral wall at a location spaced apart from the bottom wall; and

the inlet aperture is defined in the top wall.

9. The system of claim 6 wherein the bottom wall of the plenum is at least substantially square shaped.

10. The system of claim 6 wherein:

the bottom wall includes four corner areas; and

at least a portion of at least some of the plurality of outlet apertures are in each of the four corner areas.

11. The system of claim 1 wherein the air mixing chamber comprises a mixing chamber outer wall extending from the bottom wall at least substantially around the angular direction and defining a radially outwards side of the air mixing chamber.

12. The system of claim 11 wherein the mixing chamber outer wall is at least substantially quadrangular in shape.

13. The system of claim 12 wherein the mixing chamber outer wall is at least substantially square in shape.

14. The system of claim 11 further comprising a grille member extending from the mixing chamber outer wall in the radial inwards direction with the grille member comprising:

at least one louver located underneath the air mixing chamber; and

a central aperture located around the central axis.

15. The system of claim 14 wherein the grille member further comprises an upstanding wall located to be spaced radially inwards of the mixing chamber outer wall and extending toward the bottom wall, with the upstanding wall extending at least substantially around the angular direction.

16. A ventilation system comprising:

a plenum assembly comprising: an inlet aperture sized, shaped and located to receive primary air from a primary air source, a plurality of walls defining a unitary interior volume of the plenum, the plurality of walls comprising a bottom wall defining a central axis of the ventilation system, and angular and radial directions with respect to the central axis, and a plurality of outlet apertures defined in bottom wall; and

a heating/cooling unit located under the bottom wall and radially inwards of the plurality of outlet apertures, the heating/cooling unit extending at least substantially around the angular direction.

17. The system of claim 16 wherein the heating cooling unit comprises a matrix of fluid pipes.

18. The system of claim 16 wherein the heating/cooling unit has an outer footprint shaped at least substantially as a quadrangle.

19. The system of claim 16 further comprising an outer wall extending from the bottom wall in a direction away from the plenum assembly, with the outer wall extending at least substantially around the angular direction and being spaced apart radially outwards from the heating/cooling unit.

20. A ventilation system comprising:

a plenum assembly comprising: an inlet aperture sized, shaped and located to receive primary air from a primary air source, a plurality of walls defining a unitary interior volume of the plenum, the plurality of walls comprising a bottom wall defining a central axis of the ventilation system, and angular and radial directions with respect to the central axis, and a plurality of outlet apertures defined in bottom wall; and

an air mixing chamber in fluid type communication with the plenum assembly through the plurality of outlet apertures, with the air mixing chamber extending at least substantially around the angular direction; and

a heating/cooling unit located under the bottom wall and radially inwards of the air mixing chamber, the heating/cooling unit extending at least substantially around the angular direction.