US3911694A

US3911694A - Rotary cooling and heating apparatus

Info

Publication number: US3911694A
Application number: US457374A
Authority: US
Inventors: William A Doerner
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1972-02-22
Filing date: 1974-04-02
Publication date: 1975-10-14
Anticipated expiration: 1992-10-14

Abstract

Rotary cooling and heating apparatus comprising a rotary housing containing a refrigerant including a compressor and expander coupled with an external refrigerant condenser and evaporator. The components are disposed on a common axis with the condenser and evaporator axially spaced at opposite sides of the housing, and the housing, condenser and evaporator are mounted for coaxial rotation together as a unit. Rotary power means rotationally drives the compressor and the housing-condenser-evaporator, and an internal occluded fixed-ratio gear train is connected between the housing-condenser-evaporator unit and the compressor to provide different rotational speeds for the compressor and the housing-condenser-evaporator unit. The housing is hermetically sealed and a torque anchor is provided for the gear train.

Description

United States Patent I19] Doerner ROTARY COOLING AND HEATING APPARATUS [75] Inventor: William A. Doerner, Wilmington,

Del.

[73] Assignee: E. I. Du Pont de Nemours and Company. Wilmington, Del.

[22] Filed: Apr. 2, I974 [21] Appl. No.: 457,374

Related U.S. Application Data [63] Continuationdn-part of Ser. No. 316,851 Jan 2 1973, which is a continuationan-part of Ser. No. 227,901 Feh. 22 I971, abandoned.

[52] US. Cl. i i v i i 62/499; (30/669; 165/86 [5 [1 Int. Cl. i i i i i i i i i i i i 4 F258 3/00 [58] Field of Search 62/499 325, l5); 60/669; [22/] l; l65/86 87 88 [56] References Cited UNITED STATES PATENTS 181L841 ll/l957 Grimshaw i i i i i i i (13/499 100L384 9 l9ol Hanson i i i v (12/499 1 Oct. 14, 1975 3, l43,864 8/[964 SChOrdinc (12/325 PP'UHIU) Examincr-VVilliam F. ODea AASISHUP! E.taminerRonald Ci Capossela Attorney Again, or F irm-Howson and Howson [57] ABSTRACT Rotary cooling and heating apparatus comprising a rotary housing containing a refrigerant including a compressor and expander coupled with an external refrigerant condenser and evaporator. The components are disposed on a common axis with the condenser and evaporator axially spaced at opposite sides of the housing, and the housing, condenser and evaporator are mounted for coaxial rotation together as a unit, Rotary power means rotationally drives the compressor and the housing-condenser-evaporator, and an internal occluded fixed-ratio gear train is connected between the housing-condenser-evaporator unit and the compressor to provide different rotational speeds for the compressor and the housing-condenser-evaporator unit. The housing is hermetically sealed and a torque anchor is provided for the gear train.

26 CIQIITIS, I0 Drawing Figures Sheet 1 of 6 U.S. Patent US. Patent 0m. 14, 1975 Sheet 2 of6 3,911,694

Oct. 14, 1975 Sheet 3 of 6 US. Patent US. Patent 0a. 14, 1975 Sheet 4 of6 3,911,694

Oct. 14, 1975 Sheet 5 of 6 3,911,694

US. Patent A79 /0 (IV/N727? aPE/FATM/Y) ROTARY COOLING AND HEATING APPARATUS This application is a continuation-in-part of my application Ser. No. 316.85l. filed Jan. 2, 1973 which is a continuation-in-part of my application Ser. No. 227,902, filed Feb. 22. I972, now abandoned.

This invention relates to rotary cooling and heating apparatus, and more particularly to rotary cooling and heating apparatus having a rotary condenser and evaporator.

An object of the present invention is to provide a rotary cooling and heating apparatus of the type described that is of compact, unitary construction and both quiet and efficient in operation.

Another object of the invention is to provide a rotary cooling and heating apparatus of the character set forth that is operable as a reverse cycle heat pump to function either as a space cooler or heater as desired and the rotary condenser and evaporator function also as blowers for circulating the cooling or heating fluid independently of other power sources.

Another object of the invention is to provide a cooling and heating apparatus embodying the features set forth that can be manufactured and shipped fully assembled, hermetically sealed and charged with refrigerant fluid.

These and other objects of the invention and the various features and details of the construction and operation thereof are hereinafter set forth and described with reference to the accompanying drawings, in which:

FIG I is a typical sectional view diametrically through a rotary cooling and heating apparatus embodying the present invention;

FIG. 2 is an enlarged fragmentary vertical sectional view diametrically through the rotary cooling and heating apparatus;

FIG. 3 is a schematic view on line 33, FIG. 2 of the fixed-ratio gear train;

FIG. 4 is an enlarged fragmentary detail view partially in section showing the non-rotating lubricant supply conduit mounted within the high speed rotating sun gear of the gear train shown in FIG. 3;

FIG. 5 is a fragmentary sectional view in reduced scale on line S5, FIG. 2 showing details of the torque anchor pendulum;

FIG. 6 is a typical schematic sectional view diametrically through the apparatus showing an alternate arrangement of a detail of the invention;

FIG. 7 is an elevational view partially in section on line 77, FIG. 6;

FIG. 8 is a view similar to FIG. 2 showing another embodiment of the invention;

FIG. 9 is a perspective view showing the apparatus of the present invention with associated ducts and valving for cooling or air-conditioning a building in the sum mertime or other warm temperature climate; and

FIG. 10 is a view similar to FIG. 9 showing the duct valving arrangement for heating a building in the wintertime or other cold temperature climate.

Rotary cooling and heating apparatus according to the present invention comprises a rotary hermetically sealed housing H containing a refrigerant compressor P and refrigerant expander RX, together with external refrigerant condenser C and evaporator E. The compo nents are mounted on a common axis with the condenser C and evaporator E axially spaced at opposite sides ofthe housing H and mounted for coaxial rotation with the housing as a unit about said axis. Rotary power means are provided to rotationally drive the comprcs sor P and housing-condenser-cvaporator unit. and an occluded fixed-ratio gear train in the housing is connected between the latter and the compressor to provide predetermined different rotational speeds for the compressor and the housing-condenser-evaporator unit.

In the embodiment of the invention shown in FIGS. I-3 of the drawings, and with particular reference to FIG. 1 thereof. the rotary housing H is of generally cylindrical configuration comprising a circumferentially extending peripheral wall 2 and axially spaced

side walls

3 and 4. The housing H is mounted for rotation about its axis by means of shaft members 5 and 6 secured to and extending coaxially outward from the opposite

housing side walls

3 and 4, respectively. The outer end of the shaft 5 is journaled by means ofa bear ing 7 in a stationary hub 8 that is fixedly supported by means of radial spokes 9 from a circumscribing con centric ring 10 that in turn is fixedly supported by a standard 11 from a fixed base or support I2 of the apparatus. In similar manner, the outer end of the shaft 6 is rotatably journaled by means of a bearing I3 in a stationary collar or ring 14 that is supported by means of radial spokes I5 within a circumscribing concentric ring 16 that is in turn fixedly supported by a standard 17 from the fixed base I2 of the apparatus. From the foregoing it will be apparent that the cylindrical housing H and the shafts 5 and 6 constitute a unitary structure that is mounted for coaxial rotation as a unit about the housing axis.

Mounted coaxially within the housing H is a refrigerant compressor or pump P. The compressor P comprises an annular housing structure 20 that is fixedly supported within the housing H by means of radial vanes 22 so that the compressor housing 20 rotates coaxially as a unit with the housing H. The compressor housing 20 defines internally thereof a coaxial annular chamber 24 in which is mounted a compressor rotor 26 that is keyed to a shaft 28 journaled in the compressor housing 20 by means of bearings 30 and 32. Fixedly secured to and circumscribing the compressor housing 20 is an annular ring 34 having circumferentially arranged radial openings 36 therein that communicate with a corresponding plurality of eircumferentially arranged radial inlet passages 38 leading to the compressor rotor 26. An annular refrigerant chamber 40 coaxially surrounds the compressor P in radially spaced relation thereto and is fixedly supported within the housing H to rotate with the compressor housing 20 and said housing H.

In the embodiment of the invention illustrated in FIG. I of the drawings, the housing H is rotationally driven at a predetermined speed by means of an external electric motor M driving a pulley 42, fixed on the outer end of the housing shaft 6, through a belt or chain 44. An internal transmission is provided between the housing H and the compressor rotor shaft 28 so that the rotation of said housing driven by the motor M operates to rotationally drive the said shaft 28 and compressor rotor 26 at the desired speed. In the embodiment of the invention shown in FIGS. I and 2, this is accomplished by means of an internal occluded fixed-ratio gear train arranged coaxially within the housing H, and constructed and operable as described in US. Pat. No. 3.769.796 issued Nov. 6. I973 in the name of Max F. Bechtold.

As shown in FIGS. 2 and 3, the fixed-ratio gear train is in the form of a planetary gear system comprising a ring gear 46 fixedly mounted on and rotatable with the compressor housing 20 at the rotational speed at which said housing 20 and main housing H are driven by the motor M. The ring gear 46 drives a plurality of com' pound gears each rotatably mounted by means of bearings on a stub shaft 48 that is fixedly mounted in the adjacent portion ofa non-rotating torque anchor member T having a coaxially disposed central hub portion 50 that is journaled on the inner end of the shaft by means of axially spaced

bearings

52, 54 As shown, the ring gear 46 is meshed with and rotationally drives the smaller diameter gear 56 of each compound gear and the larger diameter gear 58 of each compound gear is meshed with and rotationally drives a coaxial sun gear 60 fixedly secured on the compressor shaft 28.

The torque anchor T is held stationary with respect to the rotary housing H by means of a pendulum portion 62 that projects radially substantially to the circumferential wall 2 of the housing. The pendulum is of predetermined density, dimensions and location to generate the necessary counter-torque force to oppose the reaction torque generated by the compressor.

By reason of the non-rotating torque anchor T one element of the gear train, namely the compound planetary gears, are fixedly positioned so that their axes do not rotate or move circumferentially relative to or about the housing axis. Thus the rotary power of the housing H is transmitted from the rotating ring gear 46 through the compound planetary gears directly to the sun gear 60 on the compressor shaft 28 thereby rota tionally driving said shaft and the compressor rotor 26 at the desired predetermined speed in accordance with the fixed-ratio of the gear train to compress the selected refrigerant such as, for example, Freon H3 or the like, On the other hand, with an internal motor such as is shown in FIG. 8, and hereinafter described, the compressor is driven directly and the pendulum provides the necessary counter-torque force to oppose the external reaction torque of the air drag in the rotary condenser C and evaporator E.

Refrigerant compressed by the rotor 26 is discharged therefrom through a plurality of circumferentially equally spaced radial tubes 64 to the annular refrigerant chamber 40. Compressed refrigerant discharged from the compressor P to the chamber 40 is condensed in the rotary condenser C. As shown, the rotary condenser C comprises a coaxial array of annular radial fins 66 and longitudinally extending heat exchange tubes 68 arranged circumferentially in equally spaced relation about the rotation axis of the apparatus and mounted to rotate with the housing H as previously stated. The fins 66 consist of separate or independent annular disk elements supported and secured in predetermined equally spaced parallel relation by means of the heat exchange tubes 68 that extend longitudinally through said fins 66. The fins 66 and tubes 68 are fabricated of metal having high thermal conductivity and preferably the fins are bonded to the tubes to provide maximum thermal conductivity therebetween.

The inner end portions of the heat exchange tubes 68 extend through openings 70 in the housing wall 4 and have their ends secured in recesses 72 in the adjacent wall of the refrigerant chamber 40 with the interiors of said tubes 68 in communication with the interior of said chamber 40 to receive compressed refrigerant therefrom. The outer ends of the tubes 68 are mounted and secured in recesses 74 provided in an annular end ring 76 disposed coaxially adjacent the outermost ofthe fins 66 and supported from the housing shaft 6 by circumferentially equally spaced radial spokes 78.

The inner peripheral edges ofthe fins 66 define inter nally thereofa coaxial inlet chamber 82 for the cooling fluid to be discharged outwardly by and between the plurality of rotating fins as hereinafter set forth. The inner diameters of the ring I6 and ring 76 are the same as the inner diameter of the adjacent group of fins 66 so as not to restrict the flow of fluid inwardly to the chamber 82, and an outwardly flared or bell-shaped fluid intake member 84 is fixedly mounted on the ring 16 in coaxial relation outwardly adjacent the inlet end of the chamber 82. The inner end portion of the housing shaft 6 is of curved generally conical shape as indicated at 6:1 for streamlining flow of the heat exchange fluid through the chamber 82 to the fins 66 ofthe condenser. The nature of the flow for rotational shear force devices is completely described by the Taylor number, N where:

NT" (f lm/ V d distance between fins w angular velocity (radians per sec.)

v kinematic viscosity Efficient heat exchange depends upon both the fin area and the difference between the speed of the fins and the velocity of the fluid flowing between them. For heat transfer, the Taylor number is not adequate by itself to completely describe an optimum configuration and must be determined with relation to the radio of the inner radius to the outer radius of the fins to provide an efficient heat exchanger.

Thus, the spacing or distance between the adjacent fins 66 of the condenser C is determined with relation to the rotational speed of the condenser and to the kinematic viscosity of the cooling fluid to provide a Taylor number in the range of about 5 to 10, preferably about 6, and the inner radius and outer radius of the fins is determined to provide a ratio of inner to outer radii of the fins 66 in the range of about 0.70 to 085, preferably about 0.77, so as to utilize the viscous properties of the cooling fluid and the shear forces exerted thereon by the rotating fins 66 to convey and accelerate the fluid radially outward between said fins substantially to the velocity providing optimum total heat exchange between refrigerant in the tubes 68 and the fluid passing between the fins 66 in accordance with the invention set forth and described in my co-pending application for US. patent filed Nov. 17, 1972, Ser. No. 307,612 now U.S. Pat. No. 3,866,668.

The outer peripheral portion of both the housing wall 4 and the ring 76 extend radially outward beyond the fins 66 a distance to provide annular radial flange portions F and F, respectively. that operate to augment fluid flow outwardly between the fins 66 as described in U.S. Pat. of Stanley B. Levy. No. 3,773,106, issued Nov. 20, 1973. Also, longitudinal fluid flow augmenta tion blades of the type and construction shown and described in said Levy patent can be provided between the flange portions F and F' when desired in any particular installation.

Compressed refrigerant discharged by the rotor 26 to the annular chamber 40 flows from the latter into the heat exchange tubes 68 of the condenser C where it is condensed by heat exchange with the cooling fluid, for

example air. discharged outwardly between the array of fins 66 as previously described. The liquid refrigerant thus condensed in the condenser tubes 68 flows inwardly therein to the refrigerant chamber 40 from which it is discharged by centrifugal force outwardly through a plurality of circumferentially equally spaced radially extending tubes 86 and then though a capillary tube refrigerant expander RX comprised of at least one or a plurality of capillary tubes 88 in which the con densed refrigerant is expanded and delivered to the evaporator E where it is evaporated.

The evaporator E is generally similar in construction to the condenser C previously described, and com prises a coaxial array of annular radial fins 90 and longitudinally extending heat exchange tubes 92 arranged in circumferentially equally spaced relation about the shaft 5 and mounted for rotation with the housing H and condenser C as a unit.

The inner ends of the heat exchange tubes 92 are mounted and secured in corresponding openings 94 provided in the adjacent housing wall 3 so that the interiors of the tubes 92 are in communication with the interior of the housing H. An annular distributing ring 96 having an inwardly extending annular wall portion 98 circumscribes the inner ends of the tubes 92. The outer ends of the tubes 92 are mounted and secured in recesses 100 provided in an annular end ring 102 that is disposed coaxially adjacent the outermost of the fins 90 and supported from the shaft 5 by circumferentially equally spaced radial spokes 104. The outer ends of the evaporator tubes 92 communicate with and are interconnected by an annular manifold 106 provided in the ring 102.

Referring to FIG. 1 of the drawings, the inner peripheral edges of the fins 90 define interiorly thereof a coaxial inlet chamber 108 for the heat exchange fluid to be discharged outwardly by and between the plurality of rotating fins 90 in the manner previously described in connection with the condenser C. The inner diameters of the ring [02 and the outwardly adjacent ring are the same as the inner diameter of the fins 90 so as not to restrict the flow of fluid into the chamber 108 and an outwardly flared or bell-shaped intake member 110 is fixedly mounted on the ring 10 in coaxial relation outwardly adjacent the inlet end of the chamber 108. A curved, generally conical shaped cowl 112 surrounds the shaft 5 for streamlining flow of the heat exchange fluid through chamber 108 to the array of fins 90 of the evaporator E.

Also. as in the condenser C, the outer peripheral portions of both the adjacent housing wall 3 and the ring 102 extend radially outward beyond the fins 90 a distance to provide annular radial flange portions F" and F that operate to augment fluid flow outwardly between the fins, and longitudinal fluid flow augmentation blades can be provided between the flange portions F" and F when desired, as previously described.

As in the case of the condenser C, the spacing or distance between the adjacent fins 90 of the evaporator E is determined with relation to the rotational speed of the evaporator and to the inner and outer radii of said fins 90, as previously described, so as to utilize the viscous properties ofthe fluid and the shear forces exerted thereon by the fins 90 to convey and accelerate the fluid radially outward between the fins substantially to the velocity providing optimum total heat exchange be tween the fluid discharged through the fins and the refrigerant in the tubes 92.

With more particular reference to the refrigerant ex pander RX, each capillary tube 88 is connected at its inlet end to one ofthe radial tubes 86 and extends radially outward to the housing wall 2. outboard ofthe pen dulum 62 of the torque anchor T, and then radially in ward to one of the evaporator tubes 92 of the evaporator E where the outlet and ofthc capillary tube 88 is directed into said evaporator tube 92, as shown. to discharge expanded liquid refrigerant thcreto, The expanded liquid refrigerant delivered by the capillary tubes 88 to the several evaporator tubes 92 is uniformly distributed by the ring 96 to the other evaporator tubes 92 except for a predetermined small number of said tubes 92 that have their inner ends blocked off as hereinafter described.

The length and internal diameter of the capillary tubes 88 are correlated to each other and to the number of tubes employed to match the refrigerant flow rate in the capillary expander tubes to the refrigerant flow rate through the compressor. This correlation is critical and can be determined precisely for each installation of the apparatus by a person skilled in the art of refrigeration.

In the present invention the capillary expanders 88 and the evaporator E are constructed and arranged so that the refrigerant flow rate in the capillary expander tubes 88 is automatically adjusted according to the refrigerant flow rate through the compressor P to thereby maintain the capacity balance of the refrigerant system. While it is preferred, in the case of high boiling point refrigerants such as Freon 113 previously mentioned, that the radial distance of the liquid level in the evaporator tubes 92 from the rotation axis of the apparatus be greater than the radial distance of the refrigerant condenser tubes 68 from said axis as shown in FIGS. 1 and 2, this is not necessary in the case of lower boiling point refrigerants and with some such refrigerants the evaporator tubes 92 may be at a less radial distance from the axis than the condenser tubes 68. In either arrangement the flow rate of refrigerant through the capillary expander tubes 88 is controlled by the pressure drop across the capillary expander tubes 88 which is determined not only by the difference between the pressure of the vapor at the refrigerant chamber 40 and that of the vapor at the evaporator distributor ring 96, but also by the difference in liquid level between the level r in the radially extending tubes 86 adjacent the refrigerant chamber 40 and the level in the evaporator tubes 92.

Thus. when the compressor P delivers refrigerant at a high flow rate, the liquid level r in the radial tubes 86 will move radially inward therein to provide the additional pressure necessary to drive the refrigerant through the capillary expander tubes 88 at the proper matching flow rate in relation to the delivery flow rate of the compressor P. Due to the amplifying effect of the centrifugal force created by rotation of the housing-condenser-evaporator unit, small variations in the liquid level r will compensate for wide variations in the flow rate of the refrigerant and the described arrangement of capillary expander and evaporator is operable to provide a capacity balanced system for any refrigerant flow rate from the designed flow rate of the particular arraratus to zero flow of the refrigerant.

Incorporated in the apparatus is a force feed lubrication system utilizing a Pitot pump such as shown in FIG. 2. and of the type described in my US. Pat. No. $744,246. issued July 10. 1973. As shown, the Pitot pump comprises a radial passage [10 in the pendulum 62 and torque anchor T. having at its outer end an L- shaped scoop 112, the inlet end of which is immersed in an annular bath of lubricant 114 in a sump extending circumferentially interiorly of the rotary housing H, and faces in the direction opposite the direction of rotation thereof. Adjacent the hub portion 50 of the torque anchor T the passage 110 divides into two angularly extending

branch passages

116 and 118, respectively. The passage 116 conducts lubricant internally of the hub portion 50 for lubrication of the

bearings

52 and 54. The other branch passage 118 connects to the radial leg of an inverted L-shaped connector 120 that has its horizontal leg disposed coaxially within the sun gear 60 of the gear train, for example as shown in FIG. 4, and the compressor rotor shaft 28 is provided with a coaxially extending lubricant passage 122 having

radial passages

124 and 126, respectively, disposed for lubricating the shaft bearings 30 and 32 as well as the several gears in the fixed-ratio gear train.

Rotation of the housing H relative to the stationary torque anchor T operates to pump lubricant from the bath 114 to the bearings and gears as described. Lubricant from the

bearings

52 and 54 drains into an annular collector ring 128 and is returned therefrom to the lubricant bath 114 by means of a plurality of circumferentially equally spaced tubes 130. Lubricant drains from the bearing 30 and the gear train into an annular collector ring 132 and is returned therefrom to the lubricant bath 114 by a plurality of circumferentially equally spaced tubes 134, and lubricant from the bear ings 30 and 32 is returned to the bath 114 by a plurality of tubes 136.

It will be observed in FIG. 2, that a portion of each capillary expander tube 88 adjacent the housing wall 2 is immersed in the lubricant bath 114, and as the tern perature of the lubricant bath 114 usually is higher than the temperature of the refrigerant in the tubes 88, the portions of the latter passing through the bath 114 preferably are thermally insulated from the lubricant, for example. by means of a circumscribing tubular sheath 138 of larger diameter than said tubes 88 closed at their opposite ends and filled with suitable insulating material 140.

As previously stated, expanded refrigerant is distrib uted by the ring 96 to all of the evaporator tubes 92 except at least one or a small number that have their inner ends closed. This one or small number of tubes 92, for example three circumferentially equally spaced tubes designated 92a, are closed at their inner ends by a disk or plug 142 having a central opening therein in which is secured the axially extending inner end portion 144 of a radially disposed tube 146 that has its outer end immersed in the lubricant bath 114. Lubricant that migrates into the refrigerant system will not evaporate in the evaporator tubes 92 but will flow through manifold 106 and collect in the several tubes 92:: that are closed against entrance of refrigerant thereto by the plugs 142. Lubricant collecting in the tubes 92a flows inwardly therein and is returned to the lubricant both 114 by the tubes 146. Preferably, each of the extends 180 about the internal periphery of the housing H to pre vent refrigerant from draining from the evaporator E when the apparatus is not rotating.

An alternate arrangement for returning lubricant from the evaporator E to the bath 114 is shown in FIGS. 6 and 7 ofthe drawings. Referring to FIGS. 6 and 7, this alternate arrangement is essentially similar to the arrangement previously described except that the opening in each disk or plug 142' for the inner end portion 144' ofthe tubes [46' is located adjacent the radially outermost inner surface ofthe tubes 920 so that the inner end portions 144' of said tubes are entirely immersed in the refrigerant in the tubes 92a and the tubes 146' are sized so as to provide a continual bleed of entrained lubricant from the evaporator tubes 9211 thereby preventing an excessive accumulation of buildup of lubricant in the evaporator E.

Any refrigerant migrating through the tubes 146 and 146' to the bath 114 will be vaporized since the temperature of the bath is well above the evaporator tem perature although at the same pressure. Refrigerant vaporized from the bath 114 joins the evaporated refrigerant returned to the housing H from the evaporator E.

In normal operation of the described cooling and heating apparatus, the motor M drives the housing-condenser-evaporator unit at a predetermined speed of rotation and the latter through the internal gear train drives the compressor shaft 28 and rotor 26 at the desired speed of rotation relative to the speed of the housing-condenserevaporator unit determined by the fixed-ratio of the gear train. In the embodiment of the invention shown, the direction of rotation of the shaft 28 is opposite the direction of rotation of the housing-condenser-evaporator unit.

The evaporator refrigerant in the housing H enters the compressor P through openings 36 and passages 38, is compressed by the rotor 26 and discharged through passages 64 to the annular refrigerant chamber 40. The compressed refrigerant then enters the heat exchange tubes 68 of the condenser C where it is condensed by the cooling fluid discharged outwardly between the condenser fins 66 as previously described. The condensed refrigerant returns to the annular chamber 40 and is discharged through the tubes 86 by which the expanded refrigerant is delivered to the tubes 92 of the evaporator E. The refrigerant is evaporated in the tubes 92 and then returns to the housing H to be again compressed, condensed. expanded and evaporated as de scribed.

A typical example of a rotary cooling and heating apparatus embodying the invention comprises a compressor having an effective diameter designed and operable to compress the selected refrigerant from the evaporated pressure to the condenser pressure. The fins 66 of the condenser C have an outer diameter of 13 inches and an inner diameter of 10 inches. The axial length of the array of fins 66 is 9 inches and the spacing between adjacent fins is 0.028 inches with the axes of the heat exchange tubes 68 disposed at a radius of 5.75 inches from the rotation axis of the apparatus.

The fins of the evaporator E have an outer diame ter of l4 inches and an inner diameter of 11 inches. The axial length of the array of fins 90 is 6 inches and the spacing between adjacent fins is 0.025 inches. The axially extending

evaporator tubes

92, 92a are disposed at a radius of l2.5 inches from the rotation axis of the apparatus.

The housing-condenser-evaporator unit is rotationally driven by the motor M at a speed of 2400 rpm. and the pendulum 62 made of steel in the configuration shown in FIG. has an inner radius of 6.5 inches. an outer radius of IO inches. a width of 2 inches, an arc length of 60 and weighs 17 pounds. The pendulum provides counter-torque force sufficient to hold the torque anchor T stationary and prevent rotation thereof against a reaction of 8.5 ft. lbs. which is the torque required to drive the compressor shaft 28 and rotor 26 from the rotary housing through the fixedratio gear train.

Using l,l,2-trichloro-l ,2.2-trifluoroethane as the refrigerant. the specifications of a typical operation of the described apparatus are as follows:

Condenser saturation temperature (F.] I30. Condenser pressure (psia) l8. Condenser load (Btu/hr) 36.700. Condenser air flow (cfm) 1.540. Evaporator temperature (F.) 40. Evaporator pressure (psia) 2.7 Evaporator load (Btu/hr) 26.800. Evaporator air flow (cfm) L625 The present invention is not limited to cooling and heating apparatus in which the housing-condenserevaporator unit is rotationally driven by an external source of rotary power such as the motor M. Alterna tively, the compressor shaft and rotor may be rotationally driven by an internal source of rotary power such as an electric motor mounted within the rotary housing H and an internal fixed-ratio gear train employed to drive the rotary housingcondenser-evaporator unit from the compressor shaft.

One embodiment of such an alternative arrangement is shown in FIG. 8 of the drawings. Except for the several structural differences hereinafter described, the apparatus shown in FIG. 8 is otherwise identical to the first embodiment of the invention previously described and, accordingly. elements and parts in FIG. 8 that are identical to elements and parts in the first embodiment are identified by the same reference letters and numbers to avoid unnecessary repetition of description thereof.

Referring to FIG. 8 of the drawings, an electric motor M is mounted coaxially within the rotary housing H and comprises a stator 150 and a rotor 152 having a coaxial shaft IS4. The motor stator 150 is fixedly supported within the housing H for rotation therewith by means of a tubular housing I56 and a plurality of circumferentially equally spaced radial struts 158. Secured at opposite ends of the stator 150 are end plates I60 and 162, respectively, having openings for the shaft I54 in which said shaft is rotatably mounted by means of bearings 164 and 166.

The motor M is operated by electric energy supplied with 3-phase alternating current through a three wire conductor 168 from a conventional slip-ring arrangement comprising a plurality of rotating contacts 170 and a corresponding plurality of fixed contacts 172. The rotating contacts 170 are carried by the outer end portions 174 of the housing shaft 6a journaled in the fixed hub 140 by means of bearing 13a, and the contacts 172 are mounted in the stationary hub 14a as shown.

The sun gear 60 ofthe fixed-ratio gear train is fixedly mounted on the inner end ofthe rotor shaft 154 and the ring gear 46 of said gear train is moun ed in an annular recess 168 in the inner face ofthe motor end plate I60. The compound gears 56 and 58. respectively. mesh with ring gear 46 and sun gear 60 as previously described. Thus. with the pendulum 62 holding the torque anchor T stationary the rotary power of the motor shaft I54 is transmitted by the sun gear 60 through the compound gears 56 and 58 to the ring gear 46 on the motor end plate 160, thereby rotationally driving the latter and the housing-condenser-evaporator unit at the desired predetermined speed in accordance with the fixed-ratio of the gear train.

A compressor P is mounted coaxially within the tubular motor housing 156 outwardly adjacent the end plate 162. The compressor P comprises an annular housing 176 and a rotor 178 fixedly mounted on the outer end portion of the motor shaft 154 and rotationally driven thereby. The compressor housing ]76 do fines an annular inlet 180 to the rotor [78 and an annu lar diffuser 182 and manifold 184 for the refrigerant compressed and discharged by the rotor 178. Compressed refrigerant discharged by the rotor 178 to the manifold 184 flows axially inward through a plurality of circumferentially equally spaced passages 186 formed in the motor stator and thence outwardly through a corresponding plurality of radial tubes 64 to the annular refrigerant chamber 40 from which it is condensed in the condenser C. expanded in the capillary tubes 88, and evaporated in the tubes 92 of the evaporator E, all as previously described. Flow of the compressed refrigerant through the stator passages l86 also functions to cool the motor M. Evaporated refrigerant returned to the housing H from the evaporator tubes 92 flows in a path indicated by the arrows to the inlet to the compressor P where the refrigerant is again compressed. condensed. expanded and evaporated as previ ously described.

Apparatus embodying the present invention is wellsuited for cooling or heating the interior of buildings, homes and other enclosed structures utilizing reverse cycle heat pump operation, and typical arrangements thereof for summer and winter operations are shown in FIGS. 9 and 10, respectively, of the drawings.

Referring to FIGS. 9 and 10 of the drawings, apparatus embodying the invention is shown with associated ducts and valves arranged for cooling and heating a building. respectively. Preferably, the apparatus is located adjacent a wall or walls of the building for convenient access to the atmosphere outside the building such as, for example, adjacent the corner of two

side walls

190 and 192 of a building, as shown.

In the arrangements shown. air from outside the building is admitted through a duct 194 and then directed either through a duet 196 to the condenser inlet or through a duct I98 and duct 200 to the evaporator inlet, depending upon the operative position of a suitable shutter valve 202 being provided for the purpose. A stationary housing or plenum chamber 204 encloses the rotary condenser C and air admitted to the con denser is discharged outwardly through the condenser fins where it is heated by heat exchange with the refrigerant being condensed in the condenser tubes.

The heated air discharged from the condenser into the plenum chamber 204 is discharged therefrom through a duct 206 and then either through a duet 208 and duct 2I0 to the outside of the building. or through a duct 212 and duct 214 to suitable heat outlets 2I6 appropriately located throughout the building. depending upon the operative position of a suitable shutter valve 218. Air supplied to the building through outlets 216 as described is returned to the apparatus through a duct 220 and then directed either through a duct 222 back to the inlet to the condenser C, or through the duct 200 to the evaporator inlet, depending upon the operative position of a shutter valve 224.

A stationary housing or plenum chamber 226 encloses the evaporator E and air supplied to the evaporator through duct 200 is discharged outwardly through the evaporator fins where it is cooled by heat exchange with the refrigerant being evaporated in the evaporator tubes. The cooled air discharged from the evaporator into the housing 226 is discharged therefrom through a duct 228 and then either through a duct 230 and duct 210 to the outside of the building, or through the

ducts

212 and 214 for discharge through the building outlets 216 to cool the building, depending on the operative position of a suitable shutter valve 232.

For summer or cooling operation of the apparatus, as shown in FIG. 9, the valve 202 is positioned so that all of the outside air is directed through the duct 196 to the condenser inlet and the valve 218 is positioned to cause all of the heated air discharged from the condenser through duct 206 to be directed through

ducts

208 and 210 and discharged to the exterior of the building. Also, the valve 224 is positioned as shown to cause all of the building air returned through duct 220 to be directed through duct 200 to the inlet to the evaporator where it is cooled as described and discharged from the housing 226 through the duct 228, the shutter valve 232 being positioned to cause all ofthe cooled air discharged from duct 228 to be directed through

ducts

212 and 214 and discharged through the outlets 216 to thereby cool the building.

For winter or heating operation of the apparatus, the

several valves

202, 218, 224 and 232 are positioned as shown in FIG. so that operation of the apparatus is essentially the reverse of that described for cooling a building. Thus, in the arrangement shown in FIG. 10 the outside air is caused to flow through

ducts

198 and 200 to the evaporator where it is cooled and discharged through

ducts

228, 230 and 210 to the exterior of the building, whereas all of the building air returned through duct 220 is directed through duct 222 to the condenser where it is heated and discharged through

ducts

206, 212 and 214 to the outlets 216 to heat the building. Of course, as the outdoor air temperature decreases the heating capacity of the condenser (heat pump) will be reduced, and consequently in extreme cold temperatures it may be necessary to supplement the heat delivered by the condenser by an appropriate amount of resistance (electric) heating.

From the foregoing it will be observed that the present invention provides novel rotary cooling and heating apparatus that is of compact unitary construction and can be manufactured and shipped fully assembled, hermetically sealed and charged with the desired refrigerant fluid. The apparatus provides isenthalpic expansion ofthe refrigerant fluid with automatic control ofthe capacity balance ofthe refrigerant system, and the rotary condenser and evaporator function also a blowers for circulating the cooling and heating fluids independently ot'other power sources thereby providing an apparatus that is quiet and efficient in operation.

While certain embodiments of the present invention have been illustrated and described, it is not intended to limit the invention to such disclosures and changes and modifications may be made and incorporated as desired within the scope of the claims.

I claim:

1. Rotary cooling and heating apparatus comprising.

a cylindrical housing mounted for rotation about the axis thereof,

a compressor mounted coaxially in the housing for rotation therewith including a coaxial rotor rotat able independently relative to said housing for compressing refrigerant,

a condenser mounted coaxially of the housing and rotatable therewith comprising a plurality of axially spaced annular fins having heat exchange tubes extending longitudinally thcrcthrough.

means for conducting compressed refrigerant from the compressor to the condenser heat exchange tubes for condensing said refrigerant therein by heat exchange with a fluid discharged outwardly through said fins,

refrigerant expander means in said housing for expanding condensed refrigerant received from said condenser,

an evaporator mounted coaxially of the housing and rotatable therewith comprising a plurality of axially spaced annular fins having heat exchange tubes extending longitudinally therethrough and arranged to receive refrigerant from said expander,

means for returning vaporized refrigerant from said evaporator to the housing,

means operable to rotationally drive a selected one of said rotor and housing-condenser-evaporator unit including fixed-ratio transmission means in the housing connected between the rotor and said housing constructed and arranged whereby the rotor and housing rotate at predetermined first and second relative speeds respectively and the speed of said housing is operable to cause a gaseous heat exchange fluid to be conveyed and accelerated by viscosity shear forces outwardly between the fins of the condenser and evaporator to the velocities providing optimum heat exchange between said gaseous fluid and the refrigerant in the heat exchange tubes of the condenser and evaporator,

and a torque anchor non-rotatable in said housing cooperable with said transmission means for generating the necessity counter-torque force to oppose the generated reaction torque.

2. Apparatus as claimed in claim 1 wherein the refrig erant expander comprises at least one capillary tube having a length correlated to the internal flow area thereof to match the refrigerant flow rate in the capillary expander to the refrigerant flow rate through the compressor.

3. Apparatus as claimed in claim 1 wherein the refrig erant expander comprises a plurality of capillary tubes equally spaced circumferentially of the housing and rotatable therewith, the length of said capillary tubes being correlated to the internal flow area thereof and to the number of said tubes to match the refrigerant flow rate in the capillary expander to the refrigerant flow rate through the compressor.

4. Apparatus as claimed in claim 3 wherein the capillary expander tubes are operable in response to the pressure drop across said expander tubes between the refrigerant condenser and evaporator to automatically establish and maintain capacity balance in the rel'rigei A ant system.

5. i\ppill iiiub as claimed in claim 1 wherein the refrigerant expander is operable in response to the pressure drop across said espander means between the rciriger ant condenser and evaporator to automatically est-at lish and maintain capacity balance in the refrigerant system.

6. Apparatus as claimed in claim I wherein the transmission means comprises an occluded fixed-ratio gear train mounted coaxially within the housing.

7. Apparatus as claimed in claim 6 wherein the torque anchor comprises means for anchoring at least one element of the gear train against relative rotation cireumlcrentially about the housing axis.

8. Apparatus as claimed in claim 7 wherein the counter torque force generating means comprises a pendulum member connected to the gear and having prcde tcrrnined density and dimensions operable to anchor said gear cireumlerentially with respect to the housing axis.

9. Apparatus as claimed in claim I wherein the housing-condenser-evaporator unit is rotationally driven by rotary power means externally of said unit and having driving connection thereto, and the transmission drives the compressor rotor from the driven rotary housing condenser-evaporator unit.

It). Apparatus as claimed in claim 9 wherein the transmission means comprises an occluded Fixed-ratio gear train mounted coaxially within the housing.

It. Apparatus as claimed in claim 10 wherein the torque anchor comprises means for anchoring at least one of the gears in the gear train against relative rotation circumfcrcntially about the housing axis.

12. Apparatus as claimed in claim 11 wherein the counter-torque force generating means comprises a pendulum member connected to the gear and having predetermined density and dimensions operable to an chor said gear circumferentially with respect to the housing axis.

13. Apparatus as ciaimed in claim 12 wherein the ro tary housing includes a sump for containing an annular bath of lubricant and the pendulum includes pump means operable to pump lubricant from said annular bath inwardly of the housing to lubricate the transmission means and compressor rotor.

14. Apparatus as claimed in claim I wherein the compressor rotor is rotationally driven by an internal electric motor mounted coaxially within the housing and supplied with electric current from an external source of electric power, and the transmission drives the housirig-conderiser-evaporator unit from the motor driven compressor.

15. Apparatus as claimed in claim 14 wherein the transmission means comprises an occluded fixed-ratio gear train mounted coaxially within the housing.

16. Apparatus as claimed in claim 15 wherein the torque anchor comprises means for anchoring at least one of the gears in the gear train against relative rotatron circumlerentially about the housing axis.

17. Apparatus as claimed in claim 16 wherein the counter-torque lorcc generating means comprises a pendulum member connected to the gear and having predetermined density and dimensions operable to anchor said gear circunilerentially with respect to the housing axis.

(atl

18. Apparatus as claimed ill claim 17 wherein the rotary housing includes a sump for containing an annular bath ot lubricant and the pendulum includes pump means operable to pump lubricant lrom said annular bath inwardly of the housing to lubricate the trun iins sion means and compressor rotor,

19. Apparatus as claimed in claim 14 wherein the compressed rel'rigerant discharged by the compressor rotor is utili7ed to cool the internal electric motor 20. Apparatus as claimed in claim I herein the rotary housing includes a sump for containing an annular bath of lubricant and the torture anchor means is nonrotatable with the housing and includes pump means operable to pump lubricant inwardly from said annular bath to tubricatc the transmission means and comprcs' sor rotor.

21. Apparatus as claimed in claim 20 comprising means for returning to the sump lubricant migrating into the refrigerant fluid and collected in the evaporator.

22. Apparatus as claimed in claim 2! wherein the means for returning lubricant to the sump from the evaporator comprises at least one tube having its inlet end connected to one of the evaporator heat exchange tubes to receive lubricant collected therein and having its other end disposed to discharge the lubricant in said tube to the sump.

23. Apparatus as claimed in claim 22 wherein the lu hricant return tube has its discharge end disposed 1H0 from the inlet end thereof.

24. Cooling and heating apparatus as claimed in ciaim 1 comprising a first stationary housing defining a plenum chamber enclosing the condenser for receiving heated air discharged outwardly through the condenser lips and having an axial inlet opening for air to the condenser, a second stationary housing defining a plenum chamber enclosing the evaporator for receiving cool fluid discharged outwardly through the evaporator tins and having an axial inlet opening for air to the evapora tor. fresh air inlet means. duct means connected from said fresh air inlet means to the condenser air inlet and to the evaporator air inlet first valve means selectively positionable to cause air to Flow from said fresh air inlet to one of said condenser air inlet and evaporator air inlet, heated air duct means connected to the first plc num chamber for receiving heated air discharged through the condenser tins and connected to an exhaust duct having an air outlet to the ambient atmosphere and to a distribution duct leading to a remote zone to be heated second valve means in said hot air duct means selectively positionable to cause heated air from the condenser to flow to one of said exhaust duct and said distribution duct, cool air duct means con nected to the second plenum chamber for receiving coo! air discharged from the evaporator fins and con nected to said exhaust duct and said distribution duct. third valve means in said cool air duct means selectively positionable to cause coo! air from the evaportr tor to How to one oisaid exhaust duct and said distribu tion duct. return air duct means connected to the air inlet to the evaporator and the air inlet to the condenser. and l'ourth valve means in said return air duct selectively positionable to cause return air to tlow to one of said evaporator an inlet and said condenser znr inletv 25. Apparatus as claimed in claim 24 uhcrcln tor heating operation the lirst valve is positioned to cause fresh air to flow to the evaporator inlet, the second valve means is positioned to cause heated air from the condenser plenum chamber to flow through the distributor duct to the zone to be heated, the third valve means is positioned to cause cool air from the evaporator plenum chamber to flow through the exhaust duct to the ambient atmosphere, and the fourth valve means is positioned to cause air in the return duct to flow to the condenser inlet to be reheated and recirculated.

26. Apparatus as claimed in claim 24 wherein for cooling operation the first valve means is positioned to lated.

Claims

1. Rotary cooling and heating apparatus comprising, a cylindrical housing mounted for rotation about the axis thereof, a compressor mounted coaxially in the housing for rotation therewith including a coaxial rotor rotatable independently relative to said housing for compressing refrigerant, a condenser mounted coaxially of the housing and rotatable therewith comprising a plurality of axially spaced annular fins having heat exchange tubes extending longitudinally therethrough, means for conducting compressed refrigerant from the compressor to the condenser heat exchange tubes for condensing said refrigerant therein by heat exchange with a fluid discharged outwardly through said fins, refrigerant expander means in said housing for expanding condensed refrigerant received from said condenser, an evaporator mounted coaxially of the housing and rotatable therewith comprising a plurality of axially spaced annular fins having heat exchange tubes extending longitudinally therethrough and arranged to receive refrigerant from said expander, means for returning vaporized refrigerant from said evaporator to the housing, means operable to rotationally drive a selected one of said rotor and housing-condenser-evaporator unit including fixedratio transmission means in the housing connected between the rotor and said housing constructed and arranged whereby the rotor and housing rotate at predetermined first and second relative speeds respectively and the speed of said housing is operable to cause a gaseous heat exchange fluid to be conveyed and accelerated by viscosity shear forces outwardly between the fins of the condenser and evaporator to the velocities providing optimum heat exchange between said gaseous fluid and the refrigerant in the heat exchange tubes of the condenser and evaporator, and a torque anchor non-rotatable in said housing cooperable with said transmission means for generating the necessity counter-torque force to oppose the generated reaction torque.

2. Apparatus as claimed in claim 1 wherein the refrigerant expander comprises at least one capillary tube having a length correlated to the internal flow area thereof to match the refrigerant flow rate in the capillary expander to the refrigerant flow rate through the compressor.

3. Apparatus as claimed in claim 1 wherein the refrigerant expander comprises a plurality of capillary tubes equally spaced circumferentially of the housing and rotatable therewith, the length of said capillary tubes being correlated to the internal flow area thereof and to the number of said tubes to match the refrigerant flow rate in the capillary expander to the refrigerant flow rate through the compressor.

4. Apparatus as claimed in claim 3 wherein the capillary expander tubes are operable in response to the pressure drop across said expander tubes between the refrigerant condenser and evaporator to automatically establish and maintain capacity balance in the refrigerant system.

5. Apparatus as claimed in claim 1 wherein the refrigerant expander is operable in response to the pressure drop across said expander means between the refrigerant condenser and evaporator to automatically establish and maintain capacity balance in the refrigerant system.

6. Apparatus as claimed in claim 1 wherein the transmission means comprises an occluded fixed-ratio gear train mounted coaxially within the housing.

7. Apparatus as claimed in claim 6 wherein the torque anchor comprises means for anchoring at least one element of the gear train against relative rotation circumferentially about the housing axis.

8. Apparatus as claimed in claim 7 wherein the counter-torque force generating means comprises a pendulum member connected to the gear and having predetermined density and dimensions operable to anchor said gear circumferentially with respect to the housing axis.

9. Apparatus as claimed in claim 1 wherein the housing-condenser-evaporator unit is rotationally driveN by rotary power means externally of said unit and having driving connection thereto, and the transmission drives the compressor rotor from the driven rotary housing-condenser-evaporator unit.

10. Apparatus as claimed in claim 9 wherein the transmission means comprises an occluded fixed-ratio gear train mounted coaxially within the housing.

11. Apparatus as claimed in claim 10 wherein the torque anchor comprises means for anchoring at least one of the gears in the gear train against relative rotation circumferentially about the housing axis.

12. Apparatus as claimed in claim 11 wherein the counter-torque force generating means comprises a pendulum member connected to the gear and having predetermined density and dimensions operable to anchor said gear circumferentially with respect to the housing axis.

13. Apparatus as claimed in claim 12 wherein the rotary housing includes a sump for containing an annular bath of lubricant and the pendulum includes pump means operable to pump lubricant from said annular bath inwardly of the housing to lubricate the transmission means and compressor rotor.

14. Apparatus as claimed in claim 1 wherein the compressor rotor is rotationally driven by an internal electric motor mounted coaxially within the housing and supplied with electric current from an external source of electric power, and the transmission drives the housing-condenser-evaporator unit from the motor driven compressor.

16. Apparatus as claimed in claim 15 wherein the torque anchor comprises means for anchoring at least one of the gears in the gear train against relative rotation circumferentially about the housing axis.

17. Apparatus as claimed in claim 16 wherein the counter-torque force generating means comprises a pendulum member connected to the gear and having predetermined density and dimensions operable to anchor said gear circumferentially with respect to the housing axis.

18. Apparatus as claimed in claim 17 wherein the rotary housing includes a sump for containing an annular bath of lubricant and the pendulum includes pump means operable to pump lubricant from said annular bath inwardly of the housing to lubricate the transmission means and compressor rotor.

19. Apparatus as claimed in claim 14 wherein the compressed refrigerant discharged by the compressor rotor is utilized to cool the internal electric motor.

20. Apparatus as claimed in claim 1 wherein the rotary housing includes a sump for containing an annular bath of lubricant and the torque anchor means is non-rotatable with the housing and includes pump means operable to pump lubricant inwardly from said annular bath to lubricate the transmission means and compressor rotor.

22. Apparatus as claimed in claim 21 wherein the means for returning lubricant to the sump from the evaporator comprises at least one tube having its inlet end connected to one of the evaporator heat exchange tubes to receive lubricant collected therein and having its other end disposed to discharge the lubricant in said tube to the sump.

23. Apparatus as claimed in claim 22 wherein the lubricant return tube has its discharge end disposed 180* from the inlet end thereof.

24. Cooling and heating apparatus as claimed in claim 1 comprising a first stationary housing defining a plenum chamber enclosing the condenser for receiving heated air discharged outwardly through the condenser fins and having an axial inlet opening for air to the condenser, a second stationary housing defining a plenum chamber enclosing the evaporator for receiving cool fluid discharged outwardly through the evaporator fins and having an axial inlet opening for air to the evaporator, fresh air inlet means, duct means connected from said fresh air inlet means to the condenser air inlet and to the evaporator air inlet, first valve means selectively positionable to cause air to flow from said fresh air inlet to one of said condenser air inlet and evaporator air inlet, heated air duct means connected to the first plenum chamber for receiving heated air discharged through the condenser fins and connected to an exhaust duct having an air outlet to the ambient atmosphere and to a distribution duct leading to a remote zone to be heated, second valve means in said hot air duct means selectively positionable to cause heated air from the condenser to flow to one of said exhaust duct and said distribution duct, cool air duct means connected to the second plenum chamber for receiving cool air discharged from the evaporator fins and connected to said exhaust duct and said distribution duct, third valve means in said cool air duct means selectively positionable to cause cool air from the evaporator to flow to one of said exhaust duct and said distribution duct, return air duct means connected to the air inlet to the evaporator and the air inlet to the condenser, and fourth valve means in said return air duct selectively positionable to cause return air to flow to one of said evaporator air inlet and said condenser air inlet.

25. Apparatus as claimed in claim 24 wherein for heating operation the first valve is positioned to cause fresh air to flow to the evaporator inlet, the second valve means is positioned to cause heated air from the condenser plenum chamber to flow through the distributor duct to the zone to be heated, the third valve means is positioned to cause cool air from the evaporator plenum chamber to flow through the exhaust duct to the ambient atmosphere, and the fourth valve means is positioned to cause air in the return duct to flow to the condenser inlet to be reheated and recirculated.

26. Apparatus as claimed in claim 24 wherein for cooling operation the first valve means is positioned to cause fresh air to flow to the condenser inlet, the second valve means is positioned to cause heated air from the condenser plenum chamber to flow through the exhaust duct to the ambient atmosphere, the third valve means is positioned to cause cool air from the evaporator plenum chamber to flow through the distribution duct to the zone to be cooled, and the fourth valve means is positioned to cause air in the return duct to flow to the evaporator inlet to be recooled and recirculated.