US3220212A

US3220212A - Air conditioning unit

Info

Publication number: US3220212A
Application number: US406001A
Authority: US
Inventors: Fordsmand Marc
Original assignee: FRENGER INTERNATIONAL CORP
Current assignee: FRENGER INTERNATIONAL CORP
Priority date: 1963-10-23
Filing date: 1964-10-23
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30
Also published as: DE1270260B; CH420544A; IS1422A7; OA00399A; BE654798A; GB1039328A; NL6412291A; IS601B6; AT259186B; FR1412159A

Description

Nov. 30, 1965 M, FORDSMAND 3,220,212

AIR CONDITIONING UNIT Filed Oct. 23, 1964 4 Sheets-Sheet 1 9 Fig. W

F ig. 2

INVENTOR Marc F ordsmand ORNEYS Nov. 30, 1965 Filed Oct. 23, 1964 M. FORDSMAND AIR CONDITIONING UNIT 4 Sheets-Sheet 2 F/g. 4 l/Z II4 IIZ I 3) 4 Fig. 5

INVENTOR Marc F ordsmand ORNEYS NOV. 30, 1965 FORDSMAND 3,220,212

AIR CONDITIONING UNIT Filed Oct. 23, 1964 4 Sheets-Sheet 5 Q N V V Fig. 6

Fig. 7

N INVENTOR Marc Fordsmand TTORNEYS Nov. 30, 1965 M. FORDSMAND 3,220,212

AIR CONDITIONING UNIT Filed Oct. 23, 1964 4 Sheets-Sheet 4 Fig. 8

J v V v l-lc-Rc I M CK l K F-) 1 4 0/ U0 Q INVENTOR Marc Fordsmano BY m 9a/wigm%w A ORNE'Y-S' United States Patent 3,220,212 AIR CONDITIONLNG UNllT Marc Fordsmand, Charlottenlund, Denmark, assignor to Frenger International Corporation, Bern, Switzerland, a corporation of Switzerland Filed Oct. 23, 1964, Ser. No. 406,001

Claims priority, application Denmark, Oct. 23, 1963,

5,005/ 63 Claims. (Cl. 62288) This invention relates generally to air conditioning systems, and more particularly to a heat pump unit combined with a radiant heating and cooling panel and a ventilating system.

It is an object of this invention to provide a self-contained prefabricated heat pump unit which may readily be suspended in the ceiling of a room and capable of ventilating, heating and cooling the room by means of an air flow derived directly from the atmosphere.

Another object of the invention is to provide an arrangement whereby space heating, cooling and ventilation may be achieved by means of an apparatus of simple construction and without any need for external pipe lines, elaborate ventilation ducts or fuel supply.

A further obpect of the invention is to provide a universal unit which may be selectively used either as a radiant heating or radiant cooling panel and simultaneously as a ventilating and sound damping sub-ceiling unit.

According to the invention, there is provided an air conditioning unit which is essentially characterized by the arrangement of a heat pump system enclosed in a substantially flat, box-shaped casing suspended below the ceiling of a room and including at least one heat exchanger in heat exchange relation with an air current flowing through the interior of the casing through inlet and outlet air ducts communicating with the atmosphere, and at least one other heat exchanger mounted .at or forming part of the bottom Wall of the casing and forming a radiant heating and cooling panel.

Since, on the one hand, the optimal operating conditions of a radiant heating panel or sub-ceiling require a comparatively low average temperature, e.g. of the order of some 40 C., and a comparatively large surface, and since, on the other hand, the optimal operating conditions of a heat pump also require a relatively low surface temperature of the heat exchanger operating as a heating unit, it will be appreciated that the air conditioning unit ac cording to the invention will provide for the optimal working conditions of the combined heat pump and radiant heating systems comprised in the unit.

ing panel coincides with the need for a sufllcient volume within the unit to provide for an adequate cross section of the air channels in order to enable the velocity of the air flow through said channels and hence the noise level of the air flow to be kept within reasonable limits.

According to another feature of the invention, the unit comprises a pair of partition walls extending through the casing parallel :to the sidewalls thereof and defining an air channel adjacent the side wall facing the external wall of the room and communicating with the exterior for the circulation of the external air through the casing, and air channel adjacent the opposite side wall and cornmunicat ing with the room for circulating room air through the casing and a third air channel intermediate said side channels for mounting the compressor unit pertaining to the heat pump, said partition walls being provided with air valves for connecting the intermediate air channel alternatively with one or the other of the two side channels.

Other features and embodiments of the invention and the particular advantages thereby obtained will be explained in the following detailed description with reference to the drawings.

In the drawings:

FIG. 1 is a fragmentary vertical sectional view of a room showing one end of a combined radiant panel and air-conditioning unit suspended in the ceiling ad adjacent an external wall of the room.

FIG. 2 is a fragmentary horizontal sectional View taken along the line HII in FIG. 1.

FIG. 3 is a vertical section taken along the line III-III in FIG. 2.

FIG. 4 is an enlarged fragmentary detailed view showing a vertical section of part of the bottom of the unit in a modified embodiment thereof.

FIGS. 5 and 6 are horizontal sectional views similar to FIG. 2 schematically showing the arrangement of air valves within the unit and the adjustment of the air valves when operating the unit on the heating and cooling cycles respectively.

FIG. 7 is a horizontal sectional view similar to FIG. 2 but showing auxiliary means for the removal of con densate from the heat exchangers pertaining to the unit.

FIG. 8 is a diagrammatic view of the heat pump system within the unit.

Referring to the drawings and more particularly to FIGS. 1 and 2 thereof, 1 is a ceiling and 2 an external wall of a room to be air-conditioned by means of the unit according to the invention, 3 and 4 are openings in the

Wall

2, and 5 and 6 are air ducts communicating with the holes 3 and 4 respectively and hence with the atmosphere A outside the room. 7 is a window in the

wall

2 and 8 and 9 are straps or the like members for suspending an air-conditioning unit according to the invention below the ceiling 1. This unit is generally designated as 10 and comprises .a substantially flat casing defined by a bottom Wall 11, an upper 'wall or cover 12,

side walls

13 and 14 and

end walls

15 and 16. The interior of the casing 10 communicates with the atmosphere A through the air ducts 5 and 6 connecting apertures in the side wall 13 with the openings 3 and 4 respectively.

The interior of the casing is divided into three channels or compartments by means of a pair of lengthwise extending

partitions

17 and 18 defining an external channel 10x between the

walls

13 and 17, an internal channel between the

walls

18 and 14 and an intermediary channel 10m between the

walls

17 and 18. Moreover, there is provided a wall 19 extending across the channel 10m.

Within the cavity of the unit 10 there are arranged the following main systems:

(A) A heat pump system. (B) An air flow system. (C) A condensate disposal system.

The components pertaining to these systems and their functionswill be described in the following:

(A) The heat pump system.This'comprises an electromotor-drivencompressor, C, FIGS. 2 and 8, a reversing valve RV, three heat exchangers Hx, Hi and H0 operatively associated with pressure reducing means, hereinafter generally referred to as restrictors Rx, Ri and Re respectively, a constant pressure valve CPV operatively associated with the heat exchanger Hc, unidirectional valves Ux, Ui and Uc and pipes interconnecting these components as shown in the diagram FIG. 8. The terminals or connecting points of the heat exchangers are designated as a and b, those of the compressor C as p and s and those of the reversing valve RV as p, s, x and i. These terminals also appear in FIG. 2 showing the arrangement of the heat pump components within the cavity of the unit, but the pipes interconnecting the components have been omitted in this figure for the sake of clarity.

As shown in FIG. 2, the compressor C and the reversing valve RV are located in the intermediary channel 10m between the

partitions

17 and 18, the heat exchanger Hx is located in the channel 10x between the

walls

13 and 17. This channel communicates with the air ducts and 6. The heat exchanger Hi is located in the air channel i between the

walls

14 and 18. The third heat exchanger I-Ic comprises a fiat pipe coil 100 or other tubular element heat conductively associated with the bottom plate 11 of the casing 10 or with a separate radiant heating or cooling panel 112 mounted below the bottom wall 111 as shown in FIG. 4.

In the embodiment shown in FIG. 4 the radiant heating or cooling panel comprising the plate elements 112 is mounted on the pipe coil 100 by means of semi-cylindrical flanges 113 along the edges of the plates 112 so as to provide for an eflicient heat conductive contact between the pipe coil 100 and the panel 112. The coil 100 is mounted below the bottom 111 of the unit by means of bars or girders 111a. In this embodiment the bottom wall 111 of the unit need not necessarily be made of a heat conductive material but, like the rest of the casing 10, can be made by any other suitable material such as polyester or the like.

The panel 112 may be provided with perforations 114 and a sound damping material 115 may be inserted between the panel and the bottom wall to provide for acoustical damping of the room in which the unit is suspended.

(B) T he air flow system.This comprises the air ducts 5 and 6 communicating with the air channel 10x, a blower or fan Bx in the channel 10x arranged to provide an air flow by drawing air from the atmosphere A through the opening 3 and the air duct 5 and expelling the air through the duct 6 and the opening 4 in the Wall 2. Similarly, there is provided a blower or fan Bi within the channel 10i arranged to set up an air flow entering the channel 10i through an air intake opening i in the end wall 15 and leaving the channel 10i through an air outlet opening 16x in the end wall 16. The two blowers Bx and Bi may be driven separately or, as shown in FIG. 2, by a common driving motor MB arranged in the intermediary channel 10m.

The air flow system further comprises means for mixing the fresh air flowing through the channel 10x with the room air circulating through the channel Ni and for selectively connecting the intermediate channel 10m with either the external channel 10x adjacent the wall 2 or with the inner channel 10i so as to cause a flow of cooling air for the compressor C to be mixed with the air flow in either of the channels 10x or 10i. This is achieved by means of a plurality of apertures and air valves in the

partitions

17, 18 and 19 arranged as follows: In the partition 17 adjacent the end wall there is provided an aperture 20 and an adjustable damper 30 forming an air valve between the channel 10x and a chamber 10d, FIGS. 5 and 6, defined by the end wall 15,

partitions

17 and 18 and an air filter 40 extending from the partition 17 across the channels 10m and 10i to the side wall 14.

The partition 17 further comprises two air valves 22-32 and 23-33 located at either end of the heat exchanger Hx, and the partition 18 comprises an air valve arranged opposite the air valves 23-33. Finally, there is provided an air valve 21-31 in the wall 19 extending across the intermediary channel 10m. These air valves are interconnected and operated as shown in FIGS. 5 and 6. The

obturators

33 and 34 pertaining to the valves 23-33 and 24-34 are interconnected by a connecting member 35 so that one of these valves will be open when the other is closed. Similarly the

obturators

31 and 32 pertaining to the valves 21-31 and 22-32 are interconnected so that one of these valves will be open when the other is closed, and the two pairs of valves are mechanically interconnected by means of an operating device comprising a connecting member 36 associated with a pneumatic bulb 39 and levers 37 and 38. The device further comprises a spring 39a adapted to restore the member 36 to its initial position shown in FIG. 5 upon release of pressure from the bulb 39.

(C) The condensate disposal system.Moisture from the air which condenses on the heat exchangers must be removed, and FIG. 7 shows a system for the disposal of condensate. This system comprises a pair of trays 47x and 47i located beneath the heat exchangers Hx and Hiwhich have been omitted in this figure for the sake of claritya pipe line 42 connecting the trays with a water recipient 43, a pump 44 which may be driven by the blower motor MB, a pipe 46 connecting the pump with a change-over valve for selectively connecting the pipe 46 with spraying nozzles 48x and 423i associated with the heat exchangers Hx and Hi respectively.

Thus, water accumulated in the trays 47x and 47i will flow through the pipe 42 to the recipient 43 from where it will be pumped under pressure to the distributing valve 45 which selectively connects the pump 44 with the spraying member associated with the heat exchanger operating on the heating cycle. Since the efliciency of the compressor will be increased by maintaining the surface temperature of the condenser at a suitably low level, the spraying of the heat exchanger operating on the heating cycle will improve the operating conditions of the heat pump. Moreover the spraying of the heat exchanger Hi will favourably influence the humidity of the room air. Any surplus amount of water accumulated in the recipient 43 may be removed by a drain pipe (not shown) or expelled by atomizing the water in a manner known per se.

OPERATION (A) The heat pump system HEATING When operating on the heating cycle the function of the heat pump system is substantially as follows:

The thermostatically controlled electromagnetic reversing valve RV, FIG. 8, is adjusted so as to establish the following circuits:

A liquified refrigerant contained in the pipes connecting the point Y with the unidirectional valves Ui and U0 and with the filter F will be drawn through the filter F, the pressure reducing restrictor Rx, heat exchanger Hx, reversing valve RV to the suction side Cs of the compressor C. Owing to the pressure drop in the restrictor Rx, the refrigerant will evaporate in the heat exchanger Hx which will be cooled and absorb heat from the air flowing through the channel 10x.

The gaseous refrigerant flowing from the heat exchanger I-Lr and the reversing valve RV will be compressed and consequently heated in the compressor C, and the hot gas flowing from the pressure side Cp of the compressor C through the reversing valve and the heat exchangers Hi and He will be condensed in these heat exchangers of which Hi will deliver the heat to the air flowing through the channel Ni and He will deliver the heat to the radiant panel 11 or 112.

Thus, heat absorbed from the external air by the heat exchanger Hx will be transferred to the room air through the heat exchanger Hi and will simultaneously be radiated into the room through the heat exchanger Hc associated with the radiant heating panel 11 or 112.

COOLING The reversing valve RV is now adjusted so as to establish the following circuits:

(a) Cp-RVpRVxHx-UxY-FRi-Hi- RViRVsCs game The liquified refrigerant will now be drawn through the filter F, restrictors R1 and Re, heat exchangers Hi and H wherein it will expand, evaporate and be cooled down so as to absorb heat from the room air flowing through Hi and from the cooling panel of exchanger He, and the evaporated gas will flow through the reversing valve RV to the suction side Cs of the compressor C. The hot gas will flow from the pressure side Cp of the compressor C through the reversing valve to the heat exchanger Hx wherein it will condense and deliver its heat to the external air flowing through the channel 10x. The condensed liquified refrigerant leaving the heat exchanger Hx will flow through the unidirectional valve Ux to the point Y.

The valve CPV is a constant pressure valve operating to maintain the surface temperature of the heat exchanger He and hence of the cooling panel at a suitable level to ensure that no condensation of air moisture will occur on the panel.

(B) The air flow system Referring to FIGS. 5 and 6 of the drawings, the function of the air valves shown therein is as follows:

HEATING When the heat pump system is operating on the heating cycle, the compressor heat which may amount to more than 15 percent of the total heat yielded by the heat exchangers should be utilized for space heating. For this purpose, the room air is circulated through the channel 10m comprising the compressor C, and FIG. 5 schematically shows the corresponding adjustment of the air valves:

Open: 21-61, 24-34. Closed: 22-32, 23-33 Room air entering through the aperture i and air filter 40 into channel 10i will pass through a side channel ltlc between the filter 40 and the partition 19, entering channel 10m through the aperture 21 and leaving this channel through aperture 24. This airflow will cool the condenser and will subsequently mix with the room air in the channel 10:.

COOLING When the heat pump system is operating on the cooling cycle, the position of the air valves will be reversed as shown in FIG. 6. The cooling air for the compressor will now flow from channel 10x through

apertures

22 and 23 in partition 17.

It will be noted that the function of the air valve 30 between the channel 10x and the chamber 10d intermediate the filter 40 and the end wall 15 is independent of the other air valves. In fact, this valve may be adjusted separately to provide for mixing an adjustable portion of fresh air from channel 10x with the room air.

Although the operation of the air conditioning unit according to the invention will normally depend exclusively on the function of the heat pump system as described and illustrated, auxiliary electrical heating elements 41 may be provided in the channel 10i in order to supply additional heat during exceptionally cold periods.

I claim:

1. An air conditioning unit comprising a substantially flat box-shaped casing having sideand end walls, an upper wall and a bottom wall, means for connecting the interior of the casing with an external air reservoir and means for conveying an air flow derived from said external air reservoir through the interior of the casing, a heat pump system within the casing comprising a compressor, at least two heat exchangers and pipes interconnecting the compressor and the heat exchangers and forming a circuit for circulating a refrigerant through the compressor and heat exchangers, at least one of said heat e exchangers being arranged in heat exchange relation with said air flow, and at least one other heat exchanger being arranged in heat exchange relation with a radiant heating and cooling panel subjacent the bottom wall of said casing.

2. In an air conditioning system comprising a room to be heated or cooled by means of an air flow derived from an external air reservoir an air conditioning unit arranged subjacent the ceiling of said room and comprising a hollow box-shaped casing having sideand end walls, an upper wall and a bottom wall heat conductively associated with a conduit for a heat transfer fluid in a heat pump system and forming a radiant heating or cooling panel,

air ducts connecting the interior of said casing with said external air reservoir,

means for conveying an air flow through said air ducts and the interior of said casing,

a heat exchanger within said casing arranged in heat exchanging relationship with said air flow,

a heat pump within said casing comprising a compressor unit, and a circuit for circulating a heat transfer fluid through the compressor, said circuit including said heat exchanger and said fluid conduit associated with the bottom wall of the casing.

3. In an air conditioning system as defined in claim 2 comprising means for circulating a primary air flow through said casing, means defining a primary air channel for said primary air flow and communicating with said external air reservoir, and a secondary air channel separated from said primary air channel, a pair of apertures in said casing connecting said secondary air channel with the interior of the room, means for conveying an air flow through the secondary air channel, a heat exchanger in said secondary air channel and inserted in said heat pump circuit and means for mixing an adjustable portion of air derived from the air flowing through the primary channel with the air flowing through the secondary channel.

4. An air conditioning unit comprising a substantially flat box-shaped casing having a bottom wall, side and end walls and an upper wall, said walls defining a cavity,

partition walls within said cavity defining a pair of air channels within said casing at either side thereof and a central air channel intermediate said pair of side channels,

a pair of apertures in the casing communicaitng with one of said side air channels at either end thereof and another pair of apertures in the casing communicating with the other side channel at either end thereof,

a heat exchanger in each of said side channels,

means for conveying an air current through each of said side channels between said apertures and through said heat exchangers,

apertures in said partition walls between said central channel and said side channels and air valve means operatively associated with said apertures for alternatively connecting the central channel with one of the side channels,

a third heat exchanger comprising a fluid conduit heat conductively associated with the bottom wall of the casing,

an electromotor-driven compressor within the central channel,

pipes interconnecting the compressor and the heat exchangers, said pipes and components forming a circuit for circulating a heat transfer fluid through the compressor and the heat exchanger in a heat system adapted to transfer heat from the air flowing through one of the side channels to the air flowing through the other side channel and to the bottom wall of the casing to cause said bottom wall to function as a radiant heating or cooling plaque.

5. In an air conditioning unit as defined in claim 4 an air inlet aperture in one end wall of the casing communicating with one of the side channels and an air outlet aperture in the opposite end Wall communicating with said channel, an opening in the partition wall between said side channel and the central channel adjacent one end thereof, an air filter extending transversely across the central channel and the said side channel through.

said opening, a partition wall extending transversely across the central chamber and forming one end wall thereof, an air inlet aperture in said end wall, a pair of apertures in the partition wall between the central channel and the other side channel at either end of the heat exchanger positioned therein, an aperture in the sidewall between the central channel and the first mentioned side channel connecting said channels at a point intermediate the heat exchanger in the first mentioned side channel and the air outlet aperture thereof, and valve means operatively associated with said apertures.

6. In an air conditioning system comprising a room having a ceiling and an external wall comprising an air inlet opening and an air outlet opening, an air conditioning unit as claimed in claim 4 arranged subjacent the ceiling and adjacent the external wall, side openings in the casing connecting the interior of one side channel with said air inlet and outlet openings in the external wall, an air inlet aperture in one end wall of the casing communicating with the side channel remote from the side channel adjacent the external wall of the room, an air filter extending transversely through the casing from the partition wall separating the central chamber from the side channel adjacent the external wall to the side wall of the casing remote from the external wall, an air inlet aperture in the partition wall between the central channel and the channel adjacent the external wall, said aperture being positioned between said filter and the end wall of the casing adjacent thereto, and valve means operatively associated with said aperture.

7. In an air conditioning system for ventilating and heating or cooling a room defined by a ceiling, an external wall and inner walls, a combined ventilating and radiant heating or cooling unit comprising a flat boxshaped casing positioned subjacent the ceiling and adjacent the external wall of the room and having sideand end walls and a bottom wall, partition walls within said casing defining an outer air channel adjacent one side wall thereof facing the external wall of the room, an inner air channel adjacent the opposite side wall of the casing and a central air channel intermediate said outer and inner air channels, a pair of openings in the external wall of the room forming air intake and air outlet ducts respectively, a pair of apertures in the side wall of the casing adjacent the external wall of the room each communicating with one of the openings in the external wall, a pair of apertures in the casing communicating with the said inner air channel and forming an air inlet and an air outlet at either end thereof, each of said outer and inner air channels comprising a heat exchanger and a fan for conveying an air flow through the channel between the air inlet and air outlet thereof in heat exchange relation with said heat exchangers, apertures in said partition walls between said central channel and said outer and inner channels and air valve means operatively associated with said apertures for selectively connecting said central channel with one of the said outer or inner channels, a third heat exchanger comprising a fluid conduit heat conductively associated with the bottom wall of the casing, a heat pump arrangement within the cavity of the casing comprising a compressor disposed in the central channel, pipes interconnecting the compressor and the heat exchangers to form a heat pump circuit for circulating a heat transfer fluid and adapted to transfer heat from the air flowing through one of the said outer and inner channels to the air flowing through the other channel and to the bottom wall of the casing to cause said bottom wall to function as a radiant heating or cooling plaque.

8. A combined heat pump and'ventilating unit for air conditioning of a room defined by a ceiling, inner walls and an external wall with a pair of openings adjacent the ceiling, said unit comprising a flat box-shaped casing arranged subjacent the ceiling and adjacent the openings in the external wall and having sideand end walls and a bottom wall, forming a radiant heating and cooling panel comprising a fluid conduit, heat conductively associated with the bottom wall and inserted in a heat pump circuit comprising a compressor, a pair of heat exchangers and pipes interconnecting said compressor and heat exchangers for circulating a refrigerant through said heat pump circuit, partition walls within the casing defining an outer side channel, a central channel and inner side channel, said outer channel communicating with said openings in the external wall and comprising one of said heat exchangers and a fan for conveying a flow of air through the channel between said openings, said inner channel communicating with the interior of the room at either end of the channel and comprising the other heat exchanger and a fan for conveying a flow of air through the channel and the heat exchanger therein, said central channel comprising the compressor and means for selectively connecting the central air channel with one of the other channels.

9. An air conditioning unit comprising a flat boxshaped casing having sideand end Walls, an upper Wall and a bottom wall,

air ducts connecting the interior of the casing with an external air reservoir and means for conveying a flow of external air through said air ducts and the interior of the casing,

a heat exchanger within the casing in heat exchange relationship with said air flow,

a heat pump system within the casing including said heat exchanger, a compressor unit, a heat transfer fluid and a conduit for said fluid, said conduit being heat conductively associated with the bottom wall of the casing to form a heat exchanger comprising a radiant heating or cooling panel.

10. In a unit as defined in claim 4, a condensed water evacuation system comprising a tray located beneath each of the heat exchangers in the side channels, a water recipient, pipes interconnecting said trays and said recipient, spraying means adjacent each of said heat exchangers, a pump connected with said recipient, a change-over valve connected with said pump and said spraying means for selectively connecting the recipient with the spraying means adjacent one of said heat exchangers.

References Cited by the Examiner UNITED STATES PATENTS 2,213,347 9/1940 Nelson 62-279 3,060,698 10/1962 Felter 62160 3,132,490 5/1964 Schmidt 62-160 3,143,637 8/1964 Rifenbergh 49 WILLIAM J. WYE, Primary Examiner.

Claims

1. AN AIR CONDITIONING UNIT COMPRISING A SUBSTANTIALLY FLAT BOX-SHAPED CASING HAVING SIDE- AND END WALLS, AN UPPER WALL AND A BOTTOM WALL, MEANS FOR CONNECTING THE INTERIOR OF THE CASING WITH AN EXTERNAL AIR RESERVOIR AND MEANS FOR CONVEYING AN AIR FLOW DERIVED FROM SAID EXTERNAL AIR RESERVOIR THROUGH THE INTERIOR OF THE CASING, A HEAT PUMP SYSTEM WITHIN THE CASING COMPRISING A COMPRESSOR, AT LEAST TWO HEAT EXCHANGERS AND PIPES INTERCONNECTING THE COMPRESSOR AND THE HEAT EXCHANGERS AND FORMING A CIRCUIT FOR CIRCULATING A REFRIGERANT THROUGH THE COMPRESSOR AND HEAT EXCHANGERS, AT LEAST ONE OF SAID HEAT EXCHANGERS BEING ARRANGED IN HEAT EXCHANGE RELATION WITH SAID AIR FLOW, AND AT LEAST ONE OTHER HEAT EXCHANGER BEING ARRANGED IN HEAT EXCHANGE RELATION WITH A RADIANT HEATING AND COOLING PANEL SUBJACENT THE BOTTOM WALL OF SAID CASING.