US2526391A - Room air conditioner - Google Patents

Description

Oct. 17, 1950 w, MORGAN r AL 2,526,391

R00" AIR CONDITIONER FiledAug. 4. 1948 4 Sheets-Sheet 1 Fig). 1. 2 22 INVENTOR.

P012821 1401019422, Augzmcifromeier Leonard J Salzs,

W W ATTORNEY Oct. 17, 1950 R. w. MORGAN ET AL ROOI AIR CONDITIONER 4 Sheets-Sheet 2 Filed Aug. 4, 1948 foerj PIT/($ 553 Augu omefer Leonard J Saks W%W siG. TI

RNEY

1950 R. w. MORGAN El AL 2,526,391

Room AIRYCONDITIONER Filed Aug. 4, 194a 4 Sheets-Sheet 3 INVENTOR.

Bober! Wjyorgan, AugzLsfG. Tromeier' I W%2MATTORNEY Patented Oct. 17, 1950 ROOM AIR CONDITIONER Robert W. Morgan, Hamburg, August G. Trometer, Kenmore, and Leonard J. Sahs, Hamburg, N. Y., assignors to Fedders-Quigan Corporation,

Buffalo, N. Y.

Application August 4, 1948, Serial No. 42,516

12 Claims.

This invention relates to air conditioning apparatus, and it is particularly directed to the provision of beneficial improvements in unitary or self-contained machines adapted for the comfort cooling of the air in oflice or residential rooms.

The invention has among its objects the provision of a room air conditioner having a high air cooling capacit for its size and weight, and which may be operated to cool, filter, ventilate, dehumidify, and circulate the room air; which is exceptionally quiet in operation, and wherein high operating efiiciency is maintained over a long period of time, thereby reducing the need for frequent servicing. Additionally, the invention. provides a unit which is readily installed in a window in the room to be cooled, and which occupies but little of the room space. These and other objects have been successfully attained by apparatus embodying the principles and structural features hereinafter described,-

the novelty of which will be set forth in the appended claims.

The invention will be more fully understoodfrom the following description of a typical embodiment, illustrated in the'accompanying drawings, wherein:

Fig. 1 is a front elevation of the assembled apparatus, showing the inner or room side cas- Fig, 2 is an enlarged section on the line 2-2 of Fig. 1, certain parts being shown in elevation and other parts being omitted for clarity;

Fig.3 is an enlarged fragmentary detail illustrating the attachment of the air outlet grill to the front casing;

Fig. 4 is a perspective of a grill retaining clip;

Fig. 5 is a side elevation of. the assembled apparatus mounted in a room window;

Fig. 6 is a top plan with the internal and external casings removed, certain parts being broken away and other parts being shown in section;

Fig. '7 is a side elevation comparable to Fig. 5 with the casings removed and with certain parts broken away and other parts being shown in section;

Fig. 8 is a plan of a chassis base upon which the majority of the elements are mounted; and

Figs. 9 and 10 are enlarged fragmentary sections taken on the correspondingly numbered section lines of Fig. 8.

Referring first to Figs. 1 and 5, the machine, as installed for operation, comprises a front or room side casing 2| of sheet metal or other side walls 33 each of which is formed with outsideair inlet louvers 35, and a rear face 35 formed with outside air discharge louvers 31. The top 32 and side walls 33 are provided wtih outstanding flanges 34 to facilitate sealing, as will presently be explained.

The walls 33 and 36 of the outer casing3| are secured, b means of screws 38, to the upstanding flange 39 of a rectangular open supporting frame 4| having angularly disposed sides 42, 43,

hich are also shown in dotted lines in Fig. 6. The front side, designated b the numeral 43, is adapted to rest on the sill of a window W, and it is provided with a depending flange 44 adapted to abut the outer surface of the sill, and thus provide means for definitely locating the frame wtih respect to the window. The frame 4| is mounted on the window ledge by means of pairs of adjustably interconnected brackets 45 and 46, respectively screwed to the window and frame flanges 42. Additional screws may be inserted in the sill through the flange 43, if so desired.

The supporting frame 4| is adapted to receive the chassis of the machine. The chassis base pan 5|, shown in Fig.3, and the various parts mounted thereon, is simply lifted and pushed over the flanges 42 and 43 as far as they will go, after the frame 4| and easing 3| have been mounted in the window. The pan is divided into internal and external sections by means of a bulkhead, generally. designated by the reference numeral 53, and best shown in Figs. 6 and 7. This member includes an upright wall 54 disposed transversely of the pan, marginal flanges 55 which fit within the pan flange 52, and a top interconnecting flange 56. These flanges in turn are bentto provide vertical flanges 51 and a transverse flange 58, which abut the flanges 34 on the outer casing 3| when the parts are assembled. As best shown in Figs. 5 and 6, the flanges 51 and 58 are so located, with respect to the pan 5| and frame 4|, as to be positioned above the outer edge of the window sill.

The external section of the pan, together with the outer casing 3|, form a compartment for the condensing elements of a refrigeration system, while the internal section and casing 2| provide a second compartment for the refrigerant expansion coil, over which the room air may be circulated. The refrigeration system is herein shown as being of the fractional horsepower compressor-condenser-expander type. It includes, as shown in Fig. 6 and in part in Fig. 7, a combined two-cylinder compressor and motor unit 6| (hermetic compressor type), and a condenser 62 which is cooled by a blast of air circulated by a fan 63 driven by a motor 64. Refrigerant passing the condenser 62 flows to a receiver 65, and thence to a thermostatically regulated expansion valve 66 for admission to the expansion coil 61.

The refrigeration components are connected in series by a discharge line 88 extending from the compressor to the condenser, and a feed line 68 from the receiver 65 to the inlet of the refrigerant flow control member 66. A wrapping of insulation II is positioned over the connecting length of tubing from the discharge side of the valve to the evaporator BLso that the valve' will be fully responsive in its operation to refrigerant temperatures, and will not be affected b air circulating past the valve. The evaporator is a continuous coil of tubing which is bent back and forth in serpentine fashion and is provided with fins, as shown, to extend and increase the heat transfer surface. Refrigerant entering the top of the evaporator 61 flows back and forth transversely and downwardly into a return line I2, which passes through a plugged opening in the bulkhead wall 54 along the bottom of the pan 5|, in heat exchange relationship to the feed line 89, and thence to the suction inlet of the compressor 6|. The electrical controls for the compressor motor are contained in a relay box I3, located in the external compartment. Inasmuch as the electrical connections are conventional and well known, it is considered unnecessary to illustrate them in detail.

When the compressor is operating. the fan motor 84 is also operating, to draw air in through the louvers 35 in the side walls of the outer casing 8|. The current of outside air flows over the compressor 6| and motor 64, between the blades of the fan 63, audit is discharged over thecoils and fins of the condenser 82 and out of the casing through the louvers 31. The heat of compression accordingly is removed and eliminated to the atmosphere. In order to direct the air over the condenser 52, its end plates I5 are made wider than the coil itself, and they are connected to a shroud I6 having a central opening 11 through which the tips of the fan blades project. The top of the shroud is bent, as indicated by the reference numeral 18, to cover the upper portion of the condenser, and the clearance gap therebetween is filled with an insulating strip 18.

Referring again to the internal compartment, it will be noted that the expansion coil 61 is relatively thin with respect to its length and height, and that it is formed with two finned sections of equal size which are angularly disposed with respect to each other, and a middle connecting portion from which the fins are omitted. Each finned section is blocked ofl at its ends by supporting plates 8|, formed with channeled inner edges 82 between which are positioned filter pads 83. These pads have a surface area slightly larger than the area of the finned coil sections, and therefore the fin and filter areas are substantially coextensive with each other. The im- 4 portance of this feature will be further considered hereinafter. It will be noted that the centrally located or adjacent plates 8| abut the bulkhead wall 54, thus dividing the room compartment into two inlet sections 84 and 85 of substantially the same size, and an outlet section 88.

The outlet section 86 has mounted therein a motor 81 which may be secured by an overhanging bracket 88 connected to the bulkhead flange 88. This motor operates an air circulating fan 89 of the disc or propeller type, positioned in the curved or venturi inlet opening of a cylindrical shroud 8| which constitutes a portion of an upright bafile wall 92. Each end of the wall 92 is provided with a curved wing 83 passing around the end of the adjacent outer supporting plate 8|. and overlapping the return bends of the evaporator coil. Under some conditions, as, for example, when the temperature drops rapidly and the machine continues to operate, the available refrigeration may be suflicient to cause the formation of frost on the return bends. Upon melting or breaking away, this condensate would have a tendency to drop on the floor, dripping overthe tween the barrier wall and the casing is, in practical efiect, a dead air space, although it is in communication with the room air through restricted clearance openings as will be obvious from inspection of Fig. 2.

The casing 2| is assembled by sliding and lifting. it over the front end of the chassisto abut tne flanges 51 and 58 of the bulkhead 53. It is then lowered and retained in position by screws 95 (Fig. 5) which hold the casing down on soft rubber strips 96,81, and 98, respectively positioned on the bulkhead 53, evaporator 61. and wall 92. This construction permits reducing the casing dimensions, damps vibrations which otherwise might be transmitted, and also safeguards the casing from sweating under high humidity conditions. As shown in Figs. 2 and 3. the opening 21 in the face of the casing 2| is spaced from the mouth of the shroud 9| by a ring of sponge rubber grill is circular in contour, and it has a shouldered margin I82 adapted to abut the outer face of the casing 2|. In order to retain the grill in the opening, its inner face I83 is drilled and tapped at spaced intervals to receive screws I84 which retain resilient bent keeper lugs I85 (Fig. 4). The lugs are provided with perforations I86 to receive the screws, and with reversely bent angularly disposed portions I81 which engage the flange I8 I The .body of the grill is provided with horizontal louvers I88 which are inclined with respect to the thickness of the grill, and a diametrically positioned medallion I89'which can be grasped to rotate the'grill to any desired position.: Air flowing through the shroud 8| to the room may therefore be deflected in any direction.

Operation of the fan motor 8'! alone, or in v conjunction with the condensing motors in the mounted on the bulkhead 53 and projecting from the side 24 of the casing 2I. The electrical circuits, which have been omitted for the sake of clarity, are obvious to those skilled In the art. When the fan 89 is operated, air is drawn through the louvers 25. the fllters 83 and contiguous evaporator sections, and is discharged into the room through the shroud 9| and grill 28. The fan 83 may be operated independently to recirculate, filter, and purify the room air. and it may be operated simultaneously with the compressor 8|, thereby to cool and dehumidify the air. When the air passing over the evaporator 61 is also cooled, it will usually be chilled to below its dew point, and the excess moisture will precipitate on the fins and flow by gravity to the pan 5 I. From this point it drains by gravity to the external compartment for mechanical and thermodynamical disposal to the outside air.

To obtain this effect in a simple and inexpensive manner, the internal section of the pan 5I is coated with a layer of pitch or tarry "material I I2 having a diminishing thickness toward the bulkhead 53, as best shown in Fig. '7. The pitch,

which is simply poured when hot into the slightly tilted pan, takes its own level and then hardens to produce the desired slope to the pan bottom, when the pan is installed in ,a level position. Additionally. the pitch acts as an insulating medium preventing sweating and dripping from the bottom of the pan.

The externalsection of the pan 5| is formed with slightly spaced elevated pads II 3 and 4,.

upon which the condenser fan motor 64 and compressor 6i may be mounted. The spaces between the pads, and the flange 52, thus form channels into'which the condensate is directed, small notches being cut in the bulkhead wall 54 at its base for this purpose. The pan is further formed with a depressed or trough portion II5 running transversely and located under the blades of the fan 63. These blades are encircled with a band I II; which dips slightly into the outside and room air, it is necessary to seal the apparatus in the window. Forv this purpose, strips of felt or soft rubber may be laid on the window sill underneath the overlapping portion of the frame M, and a filler strip I2I of like material may be interposed between the top of the It will be appaouter face of the sill.

6 and 53, and these may be secured with screws if desired.

It is to be noted that the various elements of the apparatus are so located that the center of gravity of the mass is over the window ledge, a perpendicular through such centerintersecting the ledge between the brackets 45 and 46 and the The weights of the condenser 62 and evaporator 61 more or less balance each other, and the location of the relatively heavy compressor BI therefore brings the center of gravity to the desired location. This is a feature of importance, as it holds the unit securely in place against extraordinary loads, and also increases the stability of the installation.

Under certain conditions, it may be desirable to ventilate the room by introducing some outside air. The organization of the various components enables this to be accomplished in a simple and effective manner. Still referring to Figs. 6 and 7, it will be noted that a somewhat trapezoidal vestibule is formed between the bulkhead 53 and the inner set of louvers 35 at the side of the casing 3| opposite the compressor 6|. This is constructed by means of a diagonally disposed wall I3I extending from the bulkhead wall 54 to the edge of the pan 5| at a region adjacent the louvers 35, and spaced ceiling and deck walls I32 and I33 horizontally located between the walls I3I and 54.

Each wall 54 and |3I is formed with an opening ordoorway I34 and I35 respectively, so located with respect to the junction of the walls that a door I36 positioned in the apex will close one opening or the other as it is swungbetween them. The door or damper is mounted on a hinge I31 secured in the apex, and it may -l:e op- I erated to close either doorway by means of a lever I38, pivoted on a bracket I39 on the wall 54, and connected to the door by an angularly disposed link I4I. The outer end I42 of the lever I 38 projects through a lower louver 25 on the inner casing wall 23, and the lever is biased to have a'rnild snap action by means of a spring 43 extending, from its inner arm to a point on the pan flange 52 adjacent the pivot. When the lever is pulled forward, as viewed in Fig. 1, the door I36 will close the opening I35 and open doorway I34, thus enabling the fan 89 to draw some outside air into the room. As the spring I43 is under sumcient tension to urge the lever I42 forward, rattling of the door, and induction through it of air from the compressor compartment, is effectively precluded. When the door is swung to its oppoouter casing 3I and the lower sash, as shown in 4 site position, shown in full lines in Fig. 6, air entering the louvers 35 is blocked away from the room, and is directed through the open doorway I35 into the machinery compartment. The door I36 may, of course, be held in some intermediate position by any suitable available means, but ordinarily such operation is not desired.

During the course of operation of a room air conditioner incorporating a filter, there is a gradual accumulation of dust and dirt on the filter which tends to reduce the efficiency and capacity of the cooling system, and also to increase the respectively screwed into the window frame and v to the sides of the casing- 3I to pinch the ranels noise level; Both of these results are obiectiom able, and the apparatus of the present invention has been so devised that they are minimized. 1 It will be appreciated that circulation of the air ate at a relatively low noise level when moving.

free air, as in the case of the usual desk fan.

asaaaai However, when the inlet side of the fan is partially blocked, and the fan is placed in a housing, the work of circulating the air is increased, with an attendant increase in power required for the fan motor. The noise level also-increases, resulting in the stated; unsatisfactory operating conditions. Experience has demonstrated that the average user is unwilling to clean the filters regularly, and accordingly, as the filters become progressively clogged, room air. conditioners, as heretofore known, become more and more unsat-. isfactory in service. I

It has been noted that the coil sections 61 are of substantially the same size, and they are symmetrically-located in the room compartment of the chassis. They-are also preferably single-pass coils, as shown, so that the width of the coil is tained at a low level. A further beneficial effect is obtained by providing the outlet compartment 86, defined by the wall 92 and shroud 9|". It has been found, for example, that by usinga funnelshaped or venturi entrance shroud, and providing a chamber between the outlet sideof the coil 61 and inlet side of the fan 89, a reduction in noise level of three decibels is obtained. This effect may be regarded as due to elimination of excessive 'eddy currents or air turbulence.

Considering next the results on this arrangement as the filter becomes clogged, it will be seen that by reason of the large area, the accumulating dirt is. distributed, and it accordingly takes longer (assuming a substantially constant dust content for the, atmosphere), for each unit area of filter to become so saturated as to materially affect the air flow. The apparatus may therefore operate over a long period of time without need for filter replacement or cleaning, and still maintain the desired high cooling efllciency and low noise level.

' This result was demonstrated by comparison of streets), this increase in noise is practically undetectable by the human ear, and the noise differential is also so low that the average person is not annoyed by it. The organization of the air circuit is therefore such as to maintain substantial uniformity of refrigerating effect with a low and substantially constant noise level under all usual operating conditions. While the invention has been described in detail with respect to a preferred embodiment, it will of course be understood thatvariations and modifications may be resorted to without departure from its principles, and it is accordingly intended that only such limitations should be imposed on its scope as are expressed in the following claims.

We claim:

1. In a room air conditioner having encased internal and external compartments adapted to be positioned respectively within and outside of a room through an opening in a wall thereof, a bulkhead wall extending transversely of the compartments and dividing one from the other, said bulkhead wall being adapted to be positioned in said opening, refrigerant condensing apparatus in the external compartment, an air cooling evaporator in the internal compartment, a vestibule wall extending from the bulkhead wall adjacent one end thereof to a portion of the external compartment, said vestibule wall separating said end .of the bulkhead wall from said condensing apthe other of said openings, additional air openings formedin the internal compartment adjacent the bulkhead opening and in, the external compartment between the bulkhead and vestibule walls, thereby to provide independent air circuits including said additional openings for the comthe air circulation and emitted noise effects when .conditioner developing one-half ton of refrigeration, and with a fan 89 having a nine inch diameter, and operating at 1600 R. P. M., the delivered air was 240 cubic feet per minute,and noise level 51.5 decibels, when the filter was clean. Under I the same conditions, except for substitution of the dirty filter, the delivered air was 222 cubic feet per minute, and the noise level 52.5 decibels. The voltage impressed on the motor 81 to maintain the speed of 1600 R. P. M. remained constant for both conditions. I

It will thus be seen that under a duplication of extreme service conditions, reduction of air flow amounted to less than ten per cent, while the noise level increased only one decibel. Inasmuch as the noise level readings were taken against a background level of 36 decibels (which figure is comparable to the levels obtaining in usual oflice buildings and along residential partments when the door is positioned to close the bulkhead opening, and a common air circuit between a portion of the external compartment ing blocking the fiow of air through said vestibule refrigerant condensing machine positioned in the external section, a refrigerant evaporator positioned in the internal section, louvers-in the walls of said casings to enable air to be circulated through each section and to be returned to its region of, introduction, a vestibule wall extending from the external wall of the bulkhead to a wall I of the external casing and overlapping at least some of the louvers in the external casing, doorways formed in the vestibule wall and the bulkhead, a door mounted between the bulkhead and vestibule wall and adapted to be swung to alter- 3. A room air conditioner comprising a casing having portions respectively adapted to be positioned in a room and outside of the room and in an opening in the wall thereof, a bulkhead dis posed transversely of the casing to define said portions and adapted to be positioned at said opening, a refrigerant condensing machine in the outside portion, a refrigerant evaporator and a fan in the room portion, said fan constituting an air circulating means, air inlet openings in said casing on op osite sides of the bulkhead respectively admitting air to the outside and room portions, a damper door opening in the bulkhead adjacent said inlet openings, a vestibule wall formed with a damper door opening extending from the bulk head opening to the outside edge of the inlet opening for the outside portion of the casing, and a damper door mounted between the bulkhead and vestibule openings and adapted to be swung to close one or the other of said openings, operating means for the door accessible from the room portion of the casing, whereby, when the damper door is positioned to close the bulkhead opening, air may circulate in two paths through said air inlet' openings to the condensing machine and evaporator, and when the damper door is positioned to close thevestibule opening, air may circulate between both said'air inlet openings and the room portion.

4. In a room air conditioner having internal and external compartments adapted to be positioned inside and outside of a, room through an opening in a wall thereof, a bulkhead extending transversely of the compartments and separating one from the other, a refrigerant condensing machine in the external compartment, an air cooling refrigerant evaporator in the internal compartment, casings for the compartments each formed with openings in the walls thereof to provide for air through the compartments, a vestibule wall extending from the bulkhead wall to the external casing and encompassing some of the air openings in said external casing, said vestibulewall being positioned between the condensing machine and said encompassed openings, said bulkhead and vestibule wall being formed with doorways adjacent each other, a damper door hinged between the doorways and adapted to be swung to alternate positions to close one doorway or the other, operating means for the damper door comprising a pivoted lever extending into the room through said internal casing and connected to said door, and a spring connected to said lever and holding the same in its alternative operating positions, whereby said door is retained against its selected open ing to close the same firmly against adventitious forces and air drafts around said opening.

5. A room air conditioner having a refrigerant condensing compartment and an air cooling compartment, a bulkhead separating the compartments, said air cooling compartment being adapted to be positioned in a room to be conditioned, a detachable casing for the air cooling compartment having top, side, and front walls, air inlet openings formed in the side walls, an air outlet opening formed in the front wall, an evaporator coil disposed transversely of the air cooling compartment and between the air inlet and air outlet openings, a baflie wall extending transversely of the air cooling compartment between the air discharge side of the coil and the opening in the front of the casing, said baflle wallbeing formed with a shroud adapted to register with the front wall opening, a fan mounted in the shroud to circulate air through the air cooling compartment, and insulating material interposed between the outlet face of the shroud and the inner surface of the front wall of the casing and the top of the casing and said bulkhead and coil, said baflie wall being slightly spaced from the casing walls.

6. In a room air conditioner having a refrigerant condensing apparatus adapted to be placed in communication with outside air and an air cooling compartment isolated therefrom and adapted to be placed in-communication with the air space of a room to be cooled, a cover casing for the air cooling compartment, a single pass finned evaporator coil mounted transversely of the compartment, a baiile wall positioned in thecompartment on one side of the evaporator and extending from end to end thereof, said wall being spaced from the surface of said evaporator, a filter mounted on the opposite side of the evaporator in close'proximity to the finned surface of the coil, said filter being relatively thin with resspect to its length and breadth and the thickness of the coil and being coextensive in area with said finned portions, air inlet louvers formed in the casing walls to admit air to the filter and thence to the finned portions of the coil, a circular shrouded opening formed in the baffle wall, a propeller fan mounted for rotation in the shrouded opening, means for rotating the fan in such direction as to induce a flow of air through the filter and evaporator for discharge through said shrouded opening, an air outlet opening formed in the casing in line with the shrouded opening and positioned in close proximity thereto, an adjustable grill mounted in the air outlet opening, and sealing means between the coil and casing to direct the air entering the air inlet openings of the easing through the filter and evaporator for discharge through the grill. i

'7. A room air conditioner comprising a supporting pan, a bulkhead positioned transversely of the pan to divide the same into external and internal compartments, a refrigerant compressor and condenser mounted in the external compartment, an air fan mounted in front of the condenser, a casing for the external compartment formed with air inlet openings on opposite sides and with an air discharge opening on a third side and adjacent the condenser, a vestibule wall formed with an opening therein positioned between the bulkhead and the casing on one side thereof and overlapping some of the air inlet openings in one of said casing sides, a damper door between the bulkhead and vestibule wall adapted to close the opening in said wall, an evaporator and air moving fan in the internal compartment, said evaporator having two finned sections respectively disposed diagonally of the pan between the forward edge thereof and the bulkhead, filters positioned on said pan in close proximity to the finned sections, said air moving fan being on the opposite side of the sections, a doorway on the bulkhead adjacent said vestibule wall, said damper door being adapted to close said bulkhead doorway alternatively to the open ing in the vestibule wall, a removable casing for the internal compartment formed with air inlet openings on the opposite sides thereof to admit air from the room between the bulkhead and fi ters, an air discharge opening in the front wall of the removable casing in registry with the fan,

and a coating of heat insulating pitch on the bottom of the pan in said internal compartment, said coating being of progressively diminishing thickness fromthe front of the pan toward the bulkhead.

11 a 8. In a room air conditioner having a compartment adapted to be positioned in a room to becooled, a supporting base, a refrigerant evaporator mounted on the base and extending I transversely thereof, a casing for the compartment, said casing being formed with air inlet louvers on opposite sides and with a circular opening in the front wall thereof, said evaporator being inter-posed between the inlet louvers and said circular opening, a shroud mounted on the base and aligned concentrically with the circular opening and overlapping the periphery thereof, a sealing ring abutting the periphery of the shroud and the inner wall of the casing to encircle said circular opening, and a circular grill positioned in said circular opening and rotatably retained therein, said grill having spaced chordal louvers inclined with respect to the plane of the front wall.

9. A room air conditioner comprising a supporting pan base, a bulkhead positioned across said base to define one side of an air cooling compartment, an evaporator mounted on the base, said evaporator comprising a continuous length of tubing having finned sections disposed diagonally from the mid portion of the bulkhead to the corners of the pan, filters mounted over the surfaces of the finned sections on the bulkhead sides thereof, said filters having effective areas coextensive with the face areas of the finned sections,

a baffle wall mounted transversely of the pan on the opposite sides of the finned sections and extending beyond the corner ends thereof, a circular shroud opening formed at the center of the baille wall, an air circulating fan positioned in said shrouded opening, a casing for the compartment, said casing being formed with air inlet louvers on opposite sides between the bulkhead and said corners and with an air outlet opening in registry with the shrouded opening.

10. A room air conditioner comprising an air circulating and-cooling compartment adapted to be positioned in a room, an air cooling evaporator and air circulating fan mounted in the compartment, a casing for the compartment formed with air inlet louvers on opposite side walls thereof and with a circular air discharge opening in the front wall, the periphery of said circular opening being flanged inwardly, said evaporator being positioned in the compartment between the side wa ls and said circular opening, a circular grill mounted in the opening, said grill being formed with spaced louvers inclined with respect to an axis of rotation taken through the center of the opening and normal to the front wall, said grill being formed with a shouldered portion engaging said flanged periphery and with a contiguous plane surface abuttingthe front wall around the opening, said flanged periphery thereby forming a track for rotatably guiding said grill around said axis, and resilient retainers extending be tween the shouldered portion and the inner surface of the wall adjacent said flanged periphery to retain said grill from axial displacement and in any osition to which it is rotated in said track. v v

1. A room air conditioner having a cooling compartment adapted to be positioned-in a room to be cooled, said compartment including a serpentine evaporator coil having tubing lengths connected by return bends, supporting brackets for the coil mounted over the return bends, walls on opposite sides of the coil, a casing for the compartment, one of said walls being formed with end portions encircling the return bends, said one wall being interposed between a wall of the casing and the evaporator and constituting a mechanical and thermal barrier therebetween, and air inlet and discharge openings in the casing on opposite faces of the coil, said barrier wall being formed with an opening aligned with one of the openings in the casing.

12. A room air conditioner having a cooling compartment adapted to be positioned in a room to be cooled, said compartment including a base, an evaporator mounted on the base transversely thereof, a batlle wall extending from end to end of the evaporator and along one edge of the base,

said baflle wall being formed with an outlet opening having an annular flanged portion positioned above the edge of the base, a casing for the compartment having top, side, and front walls, air inlet openings in the side walls to admit air to the evaporator on the side thereof remote from the battle wall, an air discharge opening in the front wall, said annular flanged portion adapted to abut the periphery of said'air discharge opening, an insulating ring interposed between said flanged portion and periphery to space the front and baiile walls, thermal insulation on the base of the compartment, and additional thermal insulation and sound deadening material interposed between the top of the casing and said evaporator to space the, evaporator and upper edge of the baille wall from direct contact with the casing.

ROBERT W. MORGAN. AUGUST G. TROMETER. LEONARD J. SAHS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date 2,240,784 Jewell May6, 1941 2,299,527 Cody Oct. 20, 1942 2,316,704 Moore Apr. 13, 1943 2,359,051 Roper Sept. 26, 1944 2,361,090 Dickey Oct. 24, 1944 2,386,883 Ames Oct. 16, 1945 2,451,366 Terry Oct. 12, 1948

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