Air conditioner

2,984,089

May 16, 1961

H, A. WHITESEL

AIR CONDITIONER

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2,984,089

May 16, 1961

H. A. WHITESEL

AIR CONDITIONER

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2,984,089

H. A. WH1TESEL

AIR CONDITIONER

May 16, 1961

Filed Nov. 12, 1958

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May 16, 1961

H. A. WHITESEL

2,984,089

AIR CONDITIONER

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United States Patent Office „ 2,984,089

Patented May 16, 1961 _: 1

2,984,089

AIR CONDITIONER ₆

Hany A. Whitesel,. Cedar Rapids, Iowa, assignor to Amana Refrigeration, Inc., Amana, Iowa, a corporation of Iowa '

Filed Nov. 12,1958, Ser. No. 773,473 ₁₀

Claims. (CI. 62—429)

The present invention pertains to air conditioners, par- 15 ticularly air conditioners adapted to be mounted in a wall or window of a room and air circulating and refrigerant cooling means therefor.

Present window air conditioners, especially those of larger capacity, are heavy, bulky and often quite noisy. 20 If their inner face is kept more or less flush with the window casement, the unit, owing to its large depth, protrudes in a very unsightly manner outside the window, and a special shelf and brackets are needed for support. Many of the larger conditioners are too wide to fit be- 25 tween the sides of many windows which limits the cooling capacity of a unit suitable for such windows. Furthermore, present-day window units tend to be quite high and thus greatly decrease the amount of light admitted through a window in which they are installed. 30

The air conditioner of the present invention permits the size, noise and weight of a unit of given capacity to be greatly reduced, particularly in depth, as compared with the usual unit of the same capacity. This reduction has been accomplished both by greatly increased efficiency 3g and by compact design. For instance, a window air conditioner of the present invention having a one ton capacity measures 25 inches wide, 13¼ inches high and 16¾ inches deep, compared with approximately 25, 15 and 28 inches, respectively, for a typical unit of the same 40 capacity now available. Obviously, therefore, an air conditioner of the present invention can easily be mounted upon the sill of many windows without even the need of any brackets to support its exterior and yet have its inner face closely flush with the inner casement of the window. Its minimum height allows a maximum amount of light to be transmitted by the window. Likewise, if the unit is permanently mounted through an opening in a wall of the room, as is often done nowadays, it will protrude inside and outside very little and sometimes -₀not at all, depending, of course, upon the thickness of the wall.

The compactness, efficiency and silence of the air conditioner of the present invention is achieved in part by a novel arrangement of the evaporator and condenser « fans. Two centrifugal-type fans, surrounded by air scrolls, the condenser fan and scroll being of the double inlet type, are used and mounted on opposite sides of a partition between the room air and outside air passages. The condenser scroll has its inlets within a chamber into which outside air is drawn through the condenser by the ⁰⁰condenser fan. One motor drives both fans and is also mounted upon the partition with substantially its entire housing encompassed within a portion of the condenser fan. Most any kind of fan employing the centrifugal principle will do so long as at least one of its inlets is ⁶⁵of sufficient size to receive the bulk of the fan motor therein. “Cage” type blowers are used in the embodiment hereinafter described because they are economical and give excellent results with a minimum height. If the latter dimension is not too important, other kinds of centrifugal fans may be used with an even greater ...

reduction in depth of the unit, but with an increase in height, for a given cooling capacity. Whatever form of centrifugal fan is used, the resulting depth of the entire blower assembly is thus little more than the sum of the widths of the condenser and evaporator scrolls. The fan unit, as it is mounted wholly on a single partition, is readily removed as a unit from the air conditioner for service and to permit better access to other parts of the remaining mechanism.

The use of a double inlet blower and scroll for the condenser permits one of the blower inlets to be placed much closer to the condenser coil than would be possible were a propeller-type of fan to be used, inasmuch as the other inlet causes air to be drawn through that portion of the coil not directly opposite the first blower inlet. In the arrangement of the present invention about 70% of the incoming air through the condenser is drawn in by the scroll inlet close to the condenser while the remaining 30% is drawn through the edges of the condenser by the other scroll inlet. Propeller-type fans, even if a shroud is used, must be some distance from the face of the coil, especially if a Small diameter fan is used, in order that there be air flow through the entire coil. Furthermore, centrifugal blowers are quieter and work more efficiently than propeller-type fans against high static pressures, which in turn allows the use of a much closer finned and thus much smaller coil, as well as lower fan speeds, for a given capacity. Similarly, a centrifugal blower for the evaporator allows the use of a much smaller evaporator coil for a given capacity. Accordingly, all dimensions of the present air conditioning unit, particularly the height and the depth, are very greatly reduced by the present blower arrangement. The blower arrangement itself is in turn also adaptable in part of in whole to other refrigerating uses where a compact and efficient blower system is required.

The efficiency of the air conditioner of the present invention is further increased by the provision of a desuperheater coil adjacent the condenser coil, and by arranging these two coils with regard to the condenser blower so that the maximum cooling efficiency is obtained from the air flow produced by the latter. Indeed, the combination of these two coils with the condenser blower of the present invention provides a highly compact and efficient refrigerant cooling unit suitable for incorporation in any air Cooled refrigerating system, such as refrigerators, freezers and so forth. In the present arrangement the hot refrigerant from the motor-compressor unit is led first entirely through the de-superheater, which is of such size as to remove just the superheat from the refrigerant. Then the refrigerant is passed through the condenser to remove the latent heat. The relatively cool outside air is pulled in through the condenser by the condenser blower and blown out by the latter through the de-superheater. Since the coil capacity needed to remove the superheat is less than that needed to remove the latent heat, the de-superheater coil can be smaller and use less rows than the condenser coil, which in turn promotes the air flow through the latter. Furthermore, both coils are proportioned so that the total resistance of each to the air flow is substantially equal and thus, for well-known reasons, the maximum possible air flow for a given blower system is obtained through both coils. A water slinger is provided on the end of the condenser blower which sprays condensate drained from the evaporator on to the condenser, which still further increases the efficiency of the unit by both reducing the amount of air needed to cool the condenser as well as the temperature of the air leaving the condenser and passing through the de-superheater.

The foregoing arrangement of de-superheater and condenser in cooperation with the condenser blower system

2.984.089

Figure 2 is a perspective view of the rear of the air conditioner with various portions cut away;

Figure 3 is a plan view of the air conditioner with the cover removed;

Figure 4 is an exploded, perspective front view of the air conditioner base and partition assembly on the one hand and the refrigerant coils and their connections on the other hand; and

Figure 5 is an exploded, perspective rear view of the 10 air conditioner base and partition assembly showing the blower system removed as a unit.

In order to facilitate understanding of the invention, reference is made to the embodiments thereof shown in the accompanying drawings and detailed descriptive 15 language is employed. It will, nevertheless, be understood that no limitation of the invention is thereby intended and that various changes and alterations are contemplated such as would ordinarily occur to one skilled in the art to which the invention relates.

Referring now to the drawings, the enclosing and supporting structure of the air conditioner comprises a case or housing composed of cover 10 provided with any form of suitable air permeable grills 11 and 12 for the room face or front and the outside face or back thereof, re25 spectively, and a rectangular base pan 13. Cover 10 fits down over base pan 13 and is removably secured in any suitable fashion to upturned flange 14 around the periphery of the latter.

Mounted upon base pan 13 are vertical partitions 15, 30 16, 17 and 18. Partition 15 is parallel to the ends of base pan 13 and approximately in the middle thereof. Partition 17 is parallel to partition 15 and inset slightly from one end of base pan 13 to form with cover 10 a fresh air passage 19 extending from back to front of the 35 unit. Partition 16 has its ends removably secured to partitions 15 and 17 and is at right angles thereto. Partitions 15, 16 and 17 form with base pan 13 and cover 10 a room air intake chamber 20 and an outside air intake chamber 21 each having an outlet therefrom com40 municating with the room air and the outside air respectively, through portions of grills 11 and 12. Partition 18 is angled from approximately the middle of partition 15 to the other side of base pan 13 near the front edge thereof to form with partition 15, base pan 13 and 45 cover 10 a room air outlet chamber 22 and a larger outside air outlet chamber 23 each having an outlet therefrom communicating with the room air and the outside - air respectively, through the remaining portions of grills 11 and 12. The outer vertical edge of partition 18 is 50 provided with an angular gasket seat 24 and the top edges of partitions 15, 16, 17, and 18 and the front vertical edge of partition 15 are bent to form flanges 25 adapted to abut cover 10. In seat 24 and upon the horizontal portions of flange 25 which with cover 10 form chamber 55 22, gaskets 26 are secured in order to sell off chamber 22 from chambers 2», 21 and 23 when cover 10 is installed. To prevent excessive collection of rain water or condensate on base pan 13, overflow drain holes 27 are provided in the rear portion of flange 14 of base pan 13 60 and in the corresponding locations in cover 10. Partitions 15,16 and 17 may also be provided with “scuppers” along the bottom edges in order to distribute rain water or condensate equally upon the respective portions of base pan 13.

The refrigerating system, which is charged with a suitable refrigerant, comprises evaporator 30 of the usual multi-row type of finned coil but with relatively closely spaced fins. The bottom of evaporator 30 is spaced from base pan 13 and evaporator 30 itself is secured in an upright position parallel to grill 11 between its end plates 31 and 31', the latter being attached in turn to the front vertical edges of partitions 15 and 18, respectively. Evaporator 30 thus extends across the room air outlet from chamber 22. Beneath evaporator 30 and covering 75 the floor of chamber 22 is secured an insulating block is superior in several respects to the usual single condenser found in prior window air conditioners. In the latter, for instance, a porton of the coil removes the superheat and the remaining portion the latent heat. Accordingly, part of the cool outside air is used only to remove the superheat, yet there is sufficient cooling capacity in the outside air to remove both the superheat and the latent heat. Thus, to use a part of the outside air to remove the superheat alone, wastes a portion of its cooling capacity. Therefore, for a given coil capacity, more air, by the use of a larger fan or higher fan speed, is required to remove the latent heat, which in turn means increased size and noise of the unit.

In the arrangement of the present invention, on the other hand, all of the relatively cool outside air is first used to remove the latent heat from the refrigerant, and the same air, though warmed by its removal of the latent heat, is still sufficiently cool as compared with the refrigerant in the de-superheater, to remove the superheat therefrom. In the single condenser type of unit, a similar result is sometimes attempted by proportioning the coil and routing the hot refrigerant so that the last row downstream of the air flow removes the superheat and the remaining upstream rows the latent heat. However, such an arrangement increases the thickness of the coil necessary and thus the size of the entire air conditioning unit. Also, it prevents the most efficient use of the condensate to cool the condenser by means of a slinger ring. Even more important, it is impossible to make the air flow resistance of each of the two portions of the coil equal in order to have maximum air flow through both. If, instead, the condenser extends over the full area of the rear of the unit, in order that the coil be as thin as possible, then louvres must be provided in the sides or top or bottom to admit or discharge the condenser cooling air, depending upon the latter’s direction through the condenser, but such louvres are more or less prohibited if the unit is to be thin enough to be encompassed within a wall or window casing, unless special ducts are used.

Furthermore a single condenser, no matter what its size, does not operate at a constant temperature throughout the path of the refrigerant therethrough, in contrast to the condenser in the present invention which removes only the latent heat from the refrigerant. This is because in single-stage condenser units there is a certain amount of “leak-back” of heat through the connecting fins from the superheat portion to the latent heat portion. In the present air conditioner the de-superheater is entirely separate from the condenser so that there is no conduction from the former to the latter.

Accordingly, it is the principal object of the present invention to provide an air conditioner of minimum overall dimensions and high efficiency for a given cooling capacity.

Another object of the present invention is the provision of a compact but efficient air cooled refrigerant condensing system.

A further object of the present invention is the provision of an air conditioner having a high efficiency twostage refrigerant condensing unit, employing a de-superheater.

Another object of the present invention is the provision of compact, silent and efficient air circulation means for a refrigerant evaporator and condenser system.

A further object of the present invention is to provide an air conditioner whose air circulating means are easily removeable as a unit for servicing.

Other and further objects, features and advantages will be apparent from the description of the preferred form of the invention which follows, read in connection with the accompanying drawings in which:

Figure 1 is an exploded, perspective view of the front of the air conditioner with the cover removed and with certain portions cut away;

The blower assembly is entirely mounted upon partition 1.6 and comprises cylindrical blower motor 50 of standard type, one end of which is secured to the middle of' partition 16 so that its shaft is horizontal and its hous5 ing projects into chamber 21. The shaft of motor 50 is double-ended and one end 51 thereof passes through partition 16 into chamber 20 and its other end 52 extends close tp the inner face of condenser 39. Room air scroll 53 is secured to chamber 20 side of partition 16, 10 the latter forming one end of scroll 53 and a vertical end partition 54 extending between partitions 15 and 17 and parallel to partition 16 forming the other end. Scroll 53 is provided with a single, circular air inlet 55 through partition 54 and is surrounded by inlet ring 56 in axial alignment With the shaft end 51 of motor 50. An air outlet 57 from scroll 53 is provided through partition 15 to chamber 22. Chamber 20, scroll 53 and chamber 22 thus form a passage or duct for the room air. A suitable single inlet blower 58 of the centrifugal type within scroll 53 with its inlet facing inlet 55 is driven from shaft end 51, the inner diameters of blower 58 and inlet ring 56 being such as to provide for a smooth flow of room air from chamber 20 to within blower 58.

On the other side of partition 16 and oppoiste and in corresponding relation to scroll 53 is mounted outside air scroll 59 having parallel ends 60 and 61. End 60 of scroll 59 is provided with a circular cutout therein to receive the housing of motor 50 therethrough. Angle brackets 62 position scroll 59 with its end 60 parallel to and spaced from partition 16 so that as much of the housing of motor 50 as possible intrudes within scroll 59. The diameter of the aforesaid cutout is of sufficient size so as to form with the motor housing an annular inlet 63 to scroll 59, and end 60 of the latter is spaced from parti35 tion 16 just enough to provide a sufficient access to inlet 63 for air from chamber 21. The depths of chamber 21 and scroll 59 are such that the other end 61 of the latter is thereby positioned close to the inner face of condenser 39. End 61 is provided with a circular air inlet ⁴θ 64 therein surrounded by inlet ring 65 in axial alignment with the shaft end 52 of motor 50. Scroll 59 is further provided with an outlet 67 therefrom through partition 16 into chamber 23. Chamber 21, scroll 59 and chamber 23 thus form a passage or duct for the outside air. ⁴3 a suitable double inlet blower 66 of the centrifugal type within scroll 59 with its respective inlets opposite inlets 63 and 64 is driven from shaft end 52, the diameters of blower 66, inlet ring 65 and annular inlet 63 being such as to provide for a smooth flow of outside air from Cham59 her 21 to within blower 66. The edges of partition 54 and the edges of outlets 57 and 67 from scrolls 53 and 59, respectively, are provided with flanges 68 which are not secured to but merely abut their respective portions of partitions 15 and 17. There is thus provided a compact 55 blower assembly which is removably secured as a unit to partitions 15 and 17.

A circular water slinger 69 of· conventional design is positioned between the inner face of condenser 39 and the face of inlet 64 and also driven from shaft end 52. Slinger 69 is of such diameter that its periphery comes to within about inch of base pan 13. The necessary speed and size of blowers 58 and 66 and motor 50 and the size of scrolls 53 and 59 for a unit of given cooling capacity are readily determined by one skilled in the art to which the invention pertains.

The front vertical edge of partition 17 is provided with a rectangular fresh air inlet 70 from fresh air passage 19. An air filter 71 of any suitable kind is removably positioned between partitions 15 and 17 on the one hand, and. 70 parallel to partition 54 between the latter and fresh air inlet 70 on the other hand, To prevent contact between filter 71 and any condensate on the floor of chamber 20, the bottom edge of filter 71 rests Upon a stand 72 mounted on base pan 13. A fresh air damper 73, operable by 75 crank 74, is hinged to partition 17 so that in its open

2,084,086 of any suitable plastic material having formed therein condensate collector basin 33 and drain trough 34 leading from the latter, through partition 15 to the floor of chamber 21. The insulating properties of block 32 prevent evaporator 30 from causing any “sweating” of the floor of chamber 22 and thus any water dripping therefrom into the room., De-superheater 35, which is usually a single row, closely finned coil, stands upright parallel to grill 12 between its end plates 36 and 36' with the bottom edge of plate 36 attached to the back portion of flange 14 by clip 37 which engages one of drain holes 27. The lower end of plate 36' is in turn secured to the back portion of flange 14 by screw 38 or similar means. Condenser 39, usually a multi-row coil with closely spaced fins, is fastened in an upright position parallel to grill 12, one of its end plates 40 being adjacent end plate 36' and secured to the back vertical edge of partition 15 and its other, end plate 40' being secured to the back vertical edge of partition 17. Thus de-superheater 35 extends across the outside air outlet from chamber 23 and condenser 39 across the outside air inlet to chamber 21. Insulating block 32 is sealed watertight with partitions 15 and 18 in order that condensate on the floor of base pan 13 does not seep between block 32 and the floor of chamber 22.

Motor compressor 41, which is of the usual hermetically sealed type, is mounted on base pan 13 in chamber 23 by means of vibration damping mountings 42. The hot refrigerant is led from the.output or high side of motor compressor 41 through line 43 to the input at the bottom ' of de-superheater 35. The output of the latter is connected in turn by line 44, which also holds de-superheater 35 in an upright position, to the input at the top of condenser 39. The liquid refrigerant from the outlet at the bottom of condenser 39 is led through return line 45 out of which it is taken in the usual manner by capillary 46 to input 47 at the top of evaporator 30. The output of the latter feeds into collector 48 and through suction line 49 to the input or suction side of motor compressor 41, thus completing the refrigerant circuit. Capillary 46 is soldered to the underside of suction line 49 in order to chill the liquid, refrigerant from condenser 39 still further. If desired, a subcooler may also be provided by first leading return line 45 from condenser 39 through the condensate collected on the floor of chamber 21.

It will be appreciated, of course, that the sizes and number of rows of evaporator 36, de-superheater 35 and condenser 39 and the size and length of capillary 46 depend upon the cooling capacity of a particular unit and the refrigerant employed. However, de-superheater 35 and condenser 39 are so proportioned capacity-wise, as between themselves, so that for the particular cooling rating of the unit, the characteristics of the refrigerant used and the available air flow through each coil, desuperheater 35 is sufficient to remove the superheat and condenser 39 the latent heat from the hot refrigerant. In addition, de-superheater 35 and condenser 39 are also proportioned so that the resistance of each to air flow therethrough is substantially the same.

These proportions are readily accomplished by a proper relation between the face area, the number of fins and the thickness of each coil. Since less capacity is needed to remove the superheat than to remove the latent heat from the refrigerant, condenser 39 may have two or more rows of coils and de-superheater 35 perhaps but one row. Thus, the/face area of each can be proportioned so that the resistance of each to airflow therethrough is very closely equal; for instance, the face area of condenser 39 may be twice that of de-superheater 35. The spacing of the fins of each coil, however, is kept as close as possible in order that the overall size of each coil be as small , as possible. The foregoing calculations and those for the remaining elements of the refrigerating system can be readily made by one skilled in the art to which the invention relates.

2,984,( position a portion of the adjacent, vertical edge of filter is across the inner or front end of passage 19 (see Figure 3).

Any of a number of well-known controls, as indicated generally at 75, may be provided for motor compressor 6 41, motor 50 and damper 71, and if desired a humidity responsive control, reverse cycle connections and control, or a room air exhaust arrangement may also be readily adapted to the unit. The controls themselves may be independently operated as shown, or may be dependently 10 connected to a master control of the kind shown, for example, in United States Patent No. 2,811,022 to Lathrop. Suitable cool air directing vanes may be provided for the air outlet portion of grill 11 and adjusted by a control such as indicated at 76. 15

The path of the refrigerant and the operation of desuperheater 35 and condenser 39 thereupon have already been described. When the unit is placed in a window or a wall of a room and motor compressor 41 and blower motor 50 are in operation, rotation of blower 66 causes 20 inlet 64 to draw outside air through that portion of condenser 39 directly opposite thereto and annular inlet 63 to draw outside air into the entire chamber 21 through the remaining portions of condenser 39. The provision of annular inlet 63 thus permits inlet 64 to be as close 25 as possible to the inner face of condenser 39 and yet insures that air will be drawn through the entire surface of condenser 39 (see Figure 3). The air entering blower 66 cools motor 50, is then expelled through outlet 67, around motor compressor 41, thus contributing also to its 30 cooling, and finally is returned to the outside through desuperheater 35 and its portion of grill 12. Since de-superheater 35 is proportioned to remove the superheat from the refrigerant, its temperature is higher than that of condenser 39 proportioned to remove the latent heat. Thus 35 the air passing through the former is still cool enough to reduce the temperature of the refrigerant therein, even though that air has been warmed by its passage through the lattter.

Condensate from evaporator 30 drains into basin 33 and from there down trough 34 on to the floor of compartment 21. When the condensate level rises above %e inch, it is picked up by slinger 69 and thrown against the incoming air stream onto condenser 39, further increasing the cooling capacity of the latter. Any condensate not evaporated on condenser 39 is returned to the floor of chamber 21 or is carried in the air stream through scroll 59 and on to de-superheater 35, augmenting its cooling capacity. Proportioning de-superheater 35 and condenser 39 to have substantially equal resistance to the air flow therethrough results in maximum possible air flow through each for a given pumping capacity of blower 66. Consequently, de-superheater 35 and condenser 39, together with motor 50, scroll 59 and blower 66 provide a compact but highly efficient refrigerant condensing system.

Room air to be cooled is drawn through grill 11, through filter 71 and into blower 58 through inlet 55. The fact that motor 50 is within blower 66 instead of blower 58 or otherwise in chamber 20, prevents motor heat from being communicated to the room air. Blower 58 expels the air from outlet 57 and returns it to the room through evaporator 30 and grill 11. If a mixture of fresh air is desired, damper 73 may be opened whereby outside air will also be drawn into blower 58 through the edge of filter 71 from passage 19 leading to the outside air through grill 12 (see Figure 3).

Inasmuch as the entire blower assembly is mounted on partition 16, removal Of its fastenings to partitions 15 aid 17 after removal of case 10 permits the entire assembly readily to be withdrawn as a unit for servicing and cleaning and to allow better access to the remainder of the, air conditioner,

If a more economical construction of the air.conditioner is desired, de-superheater 35 may be- eliminated and8....... ... . . .

condenser 39 extended across the entire rear of the unit so that a part of the condenser will be cooled by the incoming outside air to inlets 63 and 64 and the remainder by the same air upon its return to the outside through chamber 23. However, the advantages of a de-superheater, as heretofore described, will be lost. Likewise, scroll 53, partition 54 and blower 58 may be replaced by an ordinary propeller-type fan. Again however, advantages heretofore described arising from the use of a centrifugal blower will be lost and evaporator 30 will very likely need to be larger in size to have enough cooling capacity, inasmuch as when a propeller fan is used the fins of evaporator 30 cannot be so closely spaced if the air flow therethrough is to be sufficient.