US2959031A

US2959031A - Self-contained air conditioning units

Info

Publication number: US2959031A
Application number: US553501A
Authority: US
Inventors: Harold H Hopkinson; Maurice D Irwin; Vernon R Kessler
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1955-12-16
Filing date: 1955-12-16
Publication date: 1960-11-08
Anticipated expiration: 1977-11-08

Description

Nov. 8, 1960 H. H. HOPKINSON ETAL 2,959,031

SELF-CONTAINED AIR CQNDITIONING UNITS 4 Sheets-Sheet 1 Filed Dec. 16, 1955 INVENTORS. HAROLD H. HOPKINSON. MAURICE D. IRWIN. VERNON R. KESSLER.

ATTORNEY.

Nov. 8, 1960 H. H. HOPKINSON ETAL 2,959,031

SELF-CONTAINED AIR connrrmnmc. nuns Filed Dec. 16, 1955 4 Sheets-Shut 2 FIG.3

INVENTORS.

MAURICE D. IRWIN. VERNON R. KESSLER.

BY W ATTORNEY.

HAROLD H. HOPKINSON.

Nov. 8, 1960 H. H HOPKINSON ETAL 2,959,031

SELF-CONTAINED AIR CONDITIONING UNITS Filed Dec. 16, 1955 4 Sheets-Shut 3 INVENTORS. HAROLD H, HOPKINSON, MAURICE D IRWIN.

VERNON R. KESSLER.

ATTORNEY.

Nov. 8, 1960 H. H. HOPKINSON EI'AL 2,959,031

saw-commas AIR commonmc nuns Filed Dec. 16, 1955 I 4 Sheets-Sheet 4 FIG. 6

FIG. 8

FIG?

INVENTORS. HAROLD H. HOPKINSON. MAURICE D. IRWIN.

VERNON R. KESSLER.

ATTORNEY.

United States Patent SELF-CONTAINED AIR CONDITIONING UNrrs Harold H. Hopkinson, Syracuse, Maurice D. Irwin, De Witt, and Vernon R. Kessler, Syracuse, N .Y., assignors to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Dec. 16, 1955, Ser. No. 553,501

12 Claims. (Cl. 62-288) This invention relates to air conditioning units and more particularly to self-contained air conditioning units in which the air handling equipment and the refrigeration system are enclosed in a common housing.

The use of self-contained air conditioning units in homes, stores, factories and offices, is very often restricted by the inflexible character of these machines. Air in such machines is customarily introduced through an intake grille in the front of the machine and is discharged from a grille spaced above the intake grille. The lower portion of the casing of such a machine is commonly monopolized by the refrigeration equipment. The orientation of components within the machine is normally dictated by the type of evaporator coil used; this in turn controls the method of condensate removal from the coils and the orientation of the filter element. Since banks of fin coils are commonly used in such units the orientation of such components has become very conventional.

The chief object of the present invention is to provide a self-contained air conditioning unit of extreme versatility which will permit application in a wide variety of situations.

An object is to provide an evaporator coil having a novel disposition of components in which the condensate formed on the coils will converge to select points and also an evaporator which integrally provides means to increase the dehumidifying qualities of the machine.

Another object is to provide a unique condensate drip pan which will not greatly impede air flow to the evaporator coil while effectively collecting condensate dripping from the evaporator coil and which will not sweat and thereby moisten the filter elements.

A further object is to provide a unit having a novel base member which also furnishes a multi-directional air intake for the unit.

A further object is to provide a novel fan mounting which permits changing the disposition of the fan discharge. Other objects of our invention will be readily perceived from the following description.

This invention relates to a self-contained air conditioning unit comprising a casing and a multi-directional air intake which also serves as a supporting base for the cas ing. This casing has a first compartment in communication with the air intake and a fan therein secured to an adjustable fan mounting, said fan mounting being of such a nature that air being discharged from the casing may be directed in an upward or backward direction from the machine. A refrigeration system is located within a second compartment within the casing; the evaporator of this refrigeration system is disposed in the air stream induced through the first compartment of the casing. This evaporator comprises a plurality of heat exchange and baflle members which cooperate in pairs so that air impinging upon the bafiles will be directed toward the heat exchange members and be in heat exchange relation therewith. These heat exchange members comprise a plurality of parallel serpentine fin coils so arranged that condensate forming thereon will flow in a converging pattern toward 2,959,031 Patented Nov. 8, 1960 the lowermost tube of each heat exchange member. Cooperating with the evaparator is a plastic drip pan adapted to collect condensate which drips from the lowermost tube of each heat exchange member. Disposed below this drip pan is a filter element through which the air passes coming from the air intake. The drip pan is made of a plastic or an insulating material and is so constructed that it does not substantially impede air flow therethrough nor does it permit the formation of condensate on the lower extremitics thereof which might moisten the filter element.

This self-contained air conditioning unit has a further feature of being utilized in a dehumidifying capacity. At

least one of the aforementioned baffles is pivotally mounted to permit air passing through the casing to bypass one or more of the evaporator heat exchange members. In effect, this arrangement partially unloads the evaporator, which causes its temperature to decrease and thereby increase the coils dehumidifying capacity.

The attached drawings illustrate a preferred embodiment of the invention, in which Figure 1 is a perspective view of the present invention showing an external air cooled condenser and a plenum for the air discharged from the unit;

Figure 2 is a sectional view of the unit employing a water cooled condenser;

Figure 3 is a perspective view of the unit shown in Figure 2 in which a large portion of the casing is removed to indicate the orientation of the components therein;

Figure 4 is a fragmentary view of the evaparator coil showing the pivoted bafile member;

Figure 5 is a perspective view of the multi-directional air intake base member;

Figure 6 is a perspective view of the removable drip P Figures 7 and 8 are partial perspective views showing the alternate orientations of the fan mounting; and

Figure 9 is a sectional view of the base member showing means for mounting the front louvers.

Referring to the drawings there is shown in Figure 1 a self-contained air conditioning unit embodying the present invention. The unit comprises a casing 2 having a front removable panel 5 giving the unit the general shape of a rectangular parallelepiped. Mounted above the unit is a plenum 3 having louvers 4 in the front thereof through which conditioned air is discharged from the unit into the space to be conditioned. An air cooled condenser 6 is secured to the rear of the unit and is operatively connected to the refrigeration system employed by the unit. This type of air cooled condenser may be suitably attached in any desired manner to the machine and put in com munication with a supply of cooling air or it may be spaced remote from the unit and be operatively connected to the machine by suitable conduits for the refrigerant to be cooled.

This type unit may employ a water cooled condenser as shown in Figures 2 and 3 instead of this external air cooled condenser. Located centrally in the front panel of the unit is a control center 8 which may be of the type illustrated in the co-pending patent application of V. Kessler and W. A. La Grange, Serial No. 553,502, filed December 16, 1955, and now Patent No. 2,869,505.

Referring to Figures 2 and 3 there are indicated a sectional view of the machine and a perspective view of the mach'ne with a major portion of the front cover panel and a side panel removed from the unit. Figure 2 indicates the control center being connected to a suitable control box 9 wherein are situated the controls for the refrigeration system and blower fan of the unit. Behind the control box is located a suitable fan adapted to induce an air stream through the casing. In the present embodiment there is shown a centrifugal fan 10 having its discharge opening in the upper wall of the unit.

It will be noted that these figures do not indicate the plenum 3 shown in Figure 1. It will be readily appreciated that suitable duct work may be attached to this fan discharge opening for discharging the conditioned air in a space remote from the machine. This fan may be mounted in an alternate position which will be described hereinafter. During operation of this fan, air is taken in through the inlet 12 and discharged through the discharge outlet 11.

Anevaporator 13 is disposed below the fan. This evaporator comprises a plurality of heat exchange members having a plurality of baffles wherein each baffie is located adjacent a heat exchange member and cooperates therewith to form an alternate arrangement of heat exchange members and bafiles. In the present embodiment there is indicated a unit employing three heat exchange members 14, each heat exchange member comprising a pair of parallel serpentine fin coils. It will be readily apparent to one skilled in the art that a greater number of serpentine coils may be employed without departing from the spirit of the present invention. Disposed between these heat exchange members are the

baffies

16, 17 and 18. It will be noted at this point that bafile 18 is pivoted in a manner and for a purpose to be described hereinafter.

Disposed below the evaporator and occupying the forward portion of the casing is a compartment defined by the partition 19 and the front cover panel 5. Within this compartment is located components of the refrigeration system. Appearing in Figure 2 is a compressor 2% having a muffler 21. The partition 19 extends upwardly and curves under the evaporator. Generally the distance between the partition and the evaporator decreases in proximity of the cover panel 5. The purpose of this construction is to maintain a constant velocity beneath the evaporator by decreasing the cross section of the air stream as it passes each heat exchange member of the evaporator and thereby compensate for the air that has passed through the heat exchange member.

Adjacent the evaporator and attached to the rear wall of the casing is a partition 22 which extends laterally across the machine and is adapted to prevent the by-pass of air about the evaporator Without being in heat exchange relationtherewith. A drip pan 23 having a plurality of channels is located beneath the evaporator. The purpose of this drip pan is to prevent condensate formed on the evaporator from dripping onto and moistening the

filter elements

25 and 26. Condensate that falls into the drip pan 23 flows therefrom into a trough 24 which is connected to a suitable drainage system (not shown). Located in the bottom wall of the casing is an opening 27. The entire unit may be mounted upon a base member having suitable louvered openings around the periphery thereof, the base member acting as anair inlet and being in communication with the opening 27.

It will be appreciated at this point that fan serves to draw air through the louvered openings of the base member 7 (to be described hereinafter), through the opening 27, through the

filter elements

25 and 26, and through openings in the drip pan and the evaporator 13. In the evaporator 13, the air will either directly impinge upon the heat exchange members 14 and be inheat exchange relation therewith or will come into contact with the

baffles

16, 17 and 18. These bafiles' deflect these air currents towards the heat exchange members. The air is chilled as it passes through the evaporator. Condensate may be formed which subsequently flows into the drip .pan 23 and then into the trough 24 and from the unit.

diffuser 32 which may be of the type shown in the patent to F. D. Stevens, Patent No. 2,704,971, issued March 29, 1955. This diffuser is directly mounted upon the unit and is in communication with the discharge 11 of the fan 10. In this view there is also shown the drive means employed to operate the fan 10. In the present embodiment a motor 33 is attached to the rotor of the fan by means of abelt and pulley drive. This motor is operatively connected to the control box 9. Also extending from this control box are the cables 34 and 36, cable 34 being a power cable which is connected to the power supply at the junction box 35 which is wired to a suitable source of electricity. The cable 36 is operatively connected to the refrigerant compressor in the unit.

Disposed beneath the control box and the fan, there is shown the serpentine coils which comprise the evaporator and shows the means of supplying refrigerant to the individual sepentine coils from the expansion valve 37. It will be readily seen from this view that the bafile 18 is of a different construction than baffles 16 and 17.

Located beneath the

filter elements

25 and 26 is shown the refrigeration system which is of a conventional type and employs a compressor 20 which is of the reciprocating semihermetic type. Adjacent this compressor is a water cooled condenser 38 which is connected to a supply of water by line 39 and discharges through a drain line 40.

In Figure 3, the opening 27 is indicated and also an opening 28 which extends through the back wall of the unit. These openings are provided to increase the range of application of the machine. Air can be taken in from the sides and front of the machine and if desired, outside air may be employed with the present machine wherein a suitable duct maybe attached to either opening 27 or 28.

Referring to Figure 4 there is shown an enlarged fragmentary view of the evaporator with the construction of the baffle 18. There is shown the front cover panel of the unit and the drip pan 23 which abuts against the insulation 43 which is secured to the back of the cover panel 5. The purpose of this abutment is to provide a partition between the upper and lower sections of the casing and prevent air passing therethrough Without being 7 in heat exchange relation with the evaporator.

on extremely damp days it is often desired to employ an air conditioning unit in a dehumidifying capacity. It is appreciated that as air is refrigerated the capacity of the air to retain moisture is decreased thereby precipitating the moisture in the form of droplets uponthe evaporator coil. It will also'be readily appreciated that if the evaporator coil is permitted to become very cold it will dehumidify to a greater extent. This is accomplished in most self-contained air conditioning units by a by-pass. This by-pass unloads the coil and permits a portion of the air passing through the unit to avoid coming into heat exchange relation with the coil. In such an operation the unloading of the evaporator permits the refrigeration system to reach lower temperatures and in this way increase the dehumidifying character of the air conditioning process. In many applications this by-pass is merely a damper door placed above the evaporator putting the outside air in communication with the fan withoutrpassing through the evaporator. In such an op' eration it will be readily appreciated that the filter of the unit is not used and unfiltered air is being recirculated by the machine.

In the present unit, a bypass is provided within the evaporator by providing a baffle which may be movable so that its deflecting action may be discontinued and air permitted to pass about the heat exchange member without coming intoheat exchange relation therewith. This principle of operation is carried out in the present invention by the'baffie 18. It will be readily appreciated that a plurality of baffles may be, provided to'accornplishth'is function without departing from the spirit of the invention.

This baffle 18 comprises a damper 44 having a bracket 46 which is rotatably mounted upon a shaft 45. On this bracket eccentric of the pivot 45, is a notch 47. Spaced from this pin or pivot 45 is a pin 48 mounted upon the casing and operatively connected to the notch 47 by means of a C-shaped spring 49. Figure 4 shows the damper in an open position. Referring to Figures 2 and 3 the damper is shown in a closed position. In closed position the lip 50 on the damper 44 is in contact with the corresponding flange 51 of the stationary portion 52 of the baffle 18. This portion 52 extends horizontally across the top portion of the heat exchange member 14. The lip 50 is normally lined with a felt material 42 which provides an air tight gasket when the damper 44 is in closed position. It will be noted that this felt strip extends from the lip 50 along the face of the damper 44 and includes a flap which seals against the drip pan thereby assuring no uncontrolled by-passing of the evaporator by the air stream.

Again referring to Figure 4, the spring 49 comprises a part of a snap action bias for the damper 44. On installation the spring is pre-stressed so that there is a continuous tendency on the part of the spring to expand. Being eccentrically connected to the bracket 46 at notch 47 it can be readily seen that the spring exerts a counter-clockwise torque upon the damper 44. As the damper 44 is rotated in a clockwise position the C-shaped spring 49 is compressed until the notch 47 passes through the plane which is defined by the axes of the pin 48 and the pivot 45. Having intersected and passed this plane the spring is partially released and exerts a clockwise torque urging the damper member with its lip 50 into sealing engagement with the corresponding lip 51 of the horizontal section 52.

In this enlarged view the individual serpentine coils 15 are shown and each serprentine coil comprises a parallel row of horizontal tubes 53. These horizontal tubes are finned to increase their heat exchange area. The serpentine coils are placed in parallel relation with the plane of each serpentine coil being askew to a vertical plane. Refering to the drawing the tubes are placed in a staggered relation with the fins slightly overlapping. In this construction, as condensate is formed on the surface of the heat exchange member, the condensate will flow downwardly from tube to tube in a converging path to the lowermost tube of each heat exchange member. Should any of the condensate be entrained in the air stream it will fall upon an adjacent baflle and flow downwardly until it comes into contact with the lowermost tube of a heat exchange member. As the condensate collects on this lowermost tube it begins to drip downwardly into a channel of the drip pan 23.

Referring to Figure 6 this drip pan comprises a structure fabricated of polystyrene having a generally rectangular shape. Longitudinally across the rectangular shape are channels 55 which have a general L-shape. These channels are disposed under the individual heat exchange members and are adapted to collect condensate falling from the lowermost tube of each heat exchange member. Running along the short outer edges of the drip pan are the drainage channels 56. Condensate flowing from the collecting channels 55 flows into the channels 56 and, because the drip pan is at an angle, this condensate flows into the integral trough section 57 which is at the lowermost point in the drip pan. This trough has a series of perforations 58 which permits water to drain from the drip pan into the trough 24 mentioned in the description of Figure 2. These perforations perform the function of a strainer which may be cleaned by removing the drip pan from the unit.

At the opposite side of the drip pan is the front section 60, the outline of which conforms generally with the shape of the cover panel 5. As previously mentioned this section of the drip pan is in an abutting contact with the insulation on the back of the cover panel and is intended to prevent the by-pass of air around the evaporator. In order to give this structure rigidity a strip 59 is provided down the center of the unit which reenforces and stiffens the structure.

It will be noted this drip pan is fabricated of polystyrene for the specific purpose of preventing formation of condensate on the underside of the structure. The temperature of condensate formed on the evaporaotr is relatively low and as the condensate falls into the drip pan should this drip pan be of a heat conductive material the underside of the drip pan would be chilled whereby air coming into contact with the underside would have moisture condensed therefrom. A build-up of moisture would subsequently drip on to the

filter elements

25 and 26. It will be doubtlessly appreciated that after a short interval of operation under such conditions the filter would turn into a soggy mass which would impede the passage of air therethrough and subsequently make the unit totally inoperative.

Referring to Figure 5 the construction of the base member is shown. This structure comprises two side members 61 and a connecting piece 62. Each side section comprises a U-shaped sheet metal construction 63 which is intended to support physically the machine thereon. Integrally connected with this U-shaped sheet metal member are suitable flanges 65 having holes therein for suitable bolt connection to the casing 2. These side members 61 are bolted along the bottom edges of the casing member and extend along the sides thereof. In this manner the casing is supported spaced from the floor. Extending between the side portions of the U-shaped members 63 are louvers 64 which are angularly disposed. A center member 62 which comprises a plurality of louvers in parallel relation and two connecting end plates 66, extends along the front edge of the casing below the cover panel 5. Each end plate 66 has a suitable indentation 75 (Figure 9) which engages protruding pin 76 extending from the side member 61. Pin 76 in conjunction with pin 77 is adapted to hold and retain the center member 62 in a manner by which simple lifting of the center member permits removal from the machine. It will be perceived that a unique support has been provided which serves a dual purpose, namely, of supporting the machine and also providing a multi-directional air intake.

Figures 7 and 8 illustrate the novel fan mounting employed in the present invention. There is indicated the fan mounting 70 which comprises a first section 71 and a second section 72. Both sections are of a general planar nature being set at right angles to each other to complete the parallelepiped shape of the casing. These sections have identical external physical dimensions and have identically situated bolt connecting means 73. Through the first section 71 extends an opening for the fan discharge 11. This fan with its motor in the present invention is secured to the fan mounting 70. Because of the identical shape of the first and second sections, plus the existence of identical bolt connecting means, a versatile fan mounting is provided in which the fan discharge may be oreinted so that it directs air in an upward direction or in a backward direction from the machine.

In reviewing this machine it is perceived that there is presented a unit having great versatility. Heretofore, air intake means were normally confined to the front section of the self-contained air conditioning unit. In this invention air is taken in at the bottom of the machine in an unobtrusive manner from all directions and there is provided means for a duct supply of air to the machine. It will e noted that the refrigeration equipment in the present machine does not monopolize the entire bottom portion of the casing but permits air to pass from the base member through an opening in the bottom wall of the casing up to the filter elements. Above these filter elements are located the drip pan and the evaporator. A unique drip pan is presented which in cooperation with a unique evaporator design only minutely impedes the flow of air through the drip pan. This drip pan is also fabricated of an insulating material which will not sweat and it is also fabricated in a shape which makes it readily removable from the machine for easy cleaning.

The present invention provides a unique evaporator which comprises a series of parallel heat exchangers, each of which has a unique scheme of condensate collection and removal. This evaporator has a novel series of bafiles which deflect the air in such a manner as to provide a compact arrangement and also permits the provision of an integral dehumidification system by permitting one of the battles to provide a bypass about the evaporator.

A versatile fan mounting is provided which permits the fan to discharge air from the machine in an upward or backward direction. Ducts may be connected to the machine if desired to direct the air to a space remote from the machine location. A plenum may be used when the machine is placed in the space to be air conditioned.

While we have described a preferred embodiment'of the invention it will be understood the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

We claim:

1. In a self contained air conditioning unit, the combination of a casing, means for inducing air through said casing in an upward direction, air intake means for said casing, an evaporator in said casing substantially traversing said. upwardly directed air stream, said evaporator comprising a plurality of bafiies constructed and arranged in the casing at an angle with the upwardly directed air stream, said bafiles defining a plurality of passages in said casing, and at least one heat exchange member in each. of said passages, said heat exchange members each being comprised of serpentine coils placed in parallel relation with one another and the plane of each serpentine coil being askew to a vertical plane to the air stream passing through each passage whereby air passing through the evaporator is deflected by said baffles into heat exchange relation with each of said heat exchange members.

2. A self contained air conditioning unit according to 'claim 1 in which at least one of said baffies is movably mounted to provide a bypass for air about the heat exchange member located adjacent thereto.

3. A self-contained air conditioning unit according to claim 1 in which a filter element is located below said evaporator and means having openings therein are disposed between said heat exchange members and said filter element to collect condensate dripping from said heat exchange members without substantial interference with passage of air upwardly through the filter and evaporator.

4. In a self-contained air conditioning unit the combination of a casing having a generally rectangular paral- .lelepiped shape, means for inducing air through said casing in an upward direction, air intake means for said casing, an evaporator in said casing substantially travers- .ing the upwardly directed air stream, said evaporator including a plurality of substantially parallel heat exchange members and a plurality of substantially parallel baffies, said heat exchange members and baffles being angularly disposed with respect to one another whereby a portion of the air being induced through said casing impinges against the baflles and is deflected into heat exchange relation with the heat exchange members, said heat exchange members comprising a plurality of substantially horizontally disposed finned tubes having the fins of each tube overlapping a neigli boring'tube whereby ina converging path to the lowermost tube of the heat exchange member, a removable drip pan situated beneath the evaporator, said drip pan being at least partially fabricated of an insulating material and having a generally rectangular shape, said drip pan having a plurality of substantially horizontally disposed channels each channel being located substantially beneath the lowermost tube of each heat exchanger member and adapted to collect condensate dripping therefrom, atleast one edge of said drip pan comprising a drainage channel disposed normal to the parallel channels and operatively connected thereto, condensate collected in the parallel channels being directed to the drainage channel, means for passing condensate from the unit, said drainage channel being operatively associated with said last mentioned means.

5. In a self-contained air conditioning unit the combination of a casing having walls defining the shape of a rectangular parallelepiped, an adjustable fan mounting, a fan secured to said adjustablefan mounting, the bottom wall of said casing having an opening therethrough, said fan being adapted to induce an air stream from said opening through said casing, an evaporator disposed in said casing, said evaporator'comprising, a plurality of substantially parallel heat exchange members oriented askew to the air stream, said heat exchange members comprising a plurality of substantially parallel serpentine coils, a plurality of baffles, each bafile cooperating with a heat exchange member to deflect a portion of the air stream into heat exchange relation with the heat exchange member, a removable drip pan disposed below the evaporator, said drip pan comprising a plurality of channels, at least one drainage channel communicating with said first mentioned channels, each of the first mentioned channels being disposed beneath a heat exchange member and adapted to collect condensate dripping therefrom, said condensate as collected flowing into the drainage channel and then passing from the unit.

6. A self-contained air conditioning unit according to claim 5 further comprising a base member to support said casing, said base member having openings disposed substantially about the periphery thereof to permit air to pass therethrough and into the opening in the bottom wall of the casing.

7. A self-contained air conditioning unit according to claim 5 in which at least one of said bafiles is pivotally mounted to permit air to bypass said heat exchange member without passing in heat exchange relation therewith.

8. In an air conditioning unit an evaporator comprising a plurality of heat exchange members each orientated askew to a vertical plane, a plurality of substantially parallel bafiles angularly disposed with respect to said heat exchange members and constructed and arranged to deflect air passing through the evaporator into heat exchange relation with the. heat exchange members, at least one of said heat exchange members consisting of a plurality of serpentine coils, said serpentine coils having a plurality of finned tubes, said tubes being in spaced relation whereby the fins of each tube overlap fins of a neighboring tube so that condensate formed on said tubes flows from tube to tube in paths converging to the lowermost tube of the heat exchange member, each of said bafiies cooperating with an adjacent heatexchange member to deflect air into heat exchange relation therewith.

9. In an' air conditioning unit, an evaporator comprising a plurality of heat exchange members oriented askew to a vertical plane, a plurality of substantially parallel baffles angularly disposed with respect to said heat exchange members and adapted to deflect air passing through the evaporator into heat exchange relation with the heat exchange members, at least one of said heat exchange members consisting of a plurality of serpentine coila, said serpentine coils having a plurality'of finned tubeg, said tubes being in spaced relation whereby the fins of each tube overlap fins of a neighboring tube so that condensate formed on said tubes flows from tube to tube in paths converging to the lowermost tube of the heat exchange member, at least one of said baffles cooperating with a heat exchange member to deflect air into heat exchange relation therewith, said one of said baflies being pivotally mounted to permit the bafile to move out of parallelism with the adjacent bafiles whereby air bypasses the evaporator without being in heat exchange relation therewith.

10. An air conditioning unit according to claim 9 in which each of said heat exchange members comprises a serpentine coil.

11. In an air conditioning unit the combination of an evaporator; a removable drip pan, and a filter; said evaporator comprising a plurality of heat exchange members, at least one of said heat exchange members comprising a plurality of parallel serpentine coils, and a plurality of baffies on opposite sides of and between adjacent heat exchange members, at least one of which is constructed and arranged to deflect air into heat exchange relation with said one of said heat exchange members, said serpentine coils comprising a plurality of horizontal finned tubes, each coil oriented to pass condensate from each tube in a converging pattern to the lowermost tube of the heat exchange member; said filter being located beneath said evaporator to filter air passing to the evaporator; said removable drip pan being at least partially fabricated of an insulating material and being disposed between the evaporator and the filter, said drip pan comprising a plurality of channels disposed beneath the heat exchange members to collect condensate dripping from the lowermost tube of each heat exchange member.

12. In an air conditioning unit the combination of an evaporator, a removable drip pan, and a filter, said evaporator comprising a plurality of heat exchange members, at least one of said heat exchange members comprising a plurality of parallel serpentine coils, a plurality of bafiles, at least one of which deflects air into heat exchange relation with a heat exchange member, said one of said baflles having a pivotally mounted section providing a bypass for air about the evaporator without said air being in heat exchange relation therewith, said serpentine coils comprising a plurality of horizontal finned tubes, each coil oriented to pass condensate from each tube in a converging pattern to the lowermost tube of the heat exchange members, said filter being located beneath said evaporator to filter air passing to the evaporator, said removable drip pan being at least partially fabricated of an insulating material and being disposed between the evaporator and the filter, said drip pan comprising a plurality of channels adapted to collect condensate dripping from the lowermost tube of each heat exchange member.

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