WO2008077220A2

WO2008077220A2 - Window air conditioning unit with alternate drain pan designs

Info

Publication number: WO2008077220A2
Application number: PCT/BR2006/000303
Authority: WO
Inventors: Regis Silva; Rafael Schabbach; Rogério FONSECA
Original assignee: Springer Carrier Ltda
Priority date: 2006-12-22
Filing date: 2006-12-22
Publication date: 2008-07-03
Also published as: WO2008077220A3; BRPI0622207A2

Abstract

Window air conditioning units are provided with one of two possible evaporator sizes. A pair of drain pans are designed to be positioned beneath the two distinct evaporator sizes. A drain pan for association with the vertically smaller evaporator size has a vertically upwardly extending ridge to block a clearance between the evaporator and the lower portion of the housing to ensure that air pulled over the evaporator will not move around the evaporator.

Description

WINDOW AIR CONDITIONING UNIT WITH ALTERNATE DRAIN PAN DESIGNS

BACKGROUND OF THE INVENTION This application relates to a window air conditioning unit wherein a pair of alternate drain pans is provided for the evaporator to accommodate two distinct sizes of evaporator within a single housing size.

Window air conditioning units are known, and typically provide all of the components of an air conditioning unit within a single housing. The housing mounts within a window, and a partition divides an inside space from an outside space.

As known, an air conditioning unit typically includes a compressor compressing a refrigerant and delivering refrigerant to a condenser which is in the outside space. Refrigerant from the condenser passes through an expansion device, after having been cooled in the condenser. The refrigerant then passes to an evaporator, in the indoor space. Air is pulled over the evaporator, and as the air moves over the evaporator, it is cooled. This air is then delivered into an environment to be conditioned (the room with the window typically).

While the evaporator does cool the air, it also dehumidifles the air. As this dehumidiflcation occurs, water is removed from the air, and typically falls into a drain pan. The drain pan collects this water, and delivers it to the "outside" space. There are many design challenges for window air conditioning units, and in particular to make them efficient. One design challenge is to ensure that all of the indoor air drawn into the air conditioning unit to be conditioned passes over the evaporator. Thus, it is desirable to eliminate any areas of potential leakage around the evaporator coils. This might be a relatively simple design challenge if all evaporator coils were of the same size. In fact, there are distinct sizes of evaporators which may be utilized in a single sized housing.

Different sized evaporators allow different air conditioning capacities in the same casing, for instance 18kBtu/h and 24kBtu/h. Other reasons like manufacturing capacity of one or other configuration of evaporator, or cost reduction reasons, may also dictate the particular size.

In particular, in one common window air conditioning unit, there is a first evaporator which generally extends between the upper and lower surfaces of the housing. A second alternative evaporator does not extend the entire vertical distance of the housing. Typically, when this short evaporator has been utilized, foam is inserted into a space between an upper end of the evaporator and the housing. This foam serves to block air flow through this gap, as any air flow moving through this gap would avoid the evaporator coils, and would thus not be conditioned. However, the requirement of the foam material adds additional costs and processing steps.

SUMMARY OF THE INVENTION In the disclosed embodiment of this invention, a first drain pan is utilized when the evaporator extends for the majority of the vertical distance of the housing. A second alternative drain pan extends for a greater vertical extent, and it blocks the space between the shorter evaporator and the housing. In both evaporator types, the evaporator extends to the vertically uppermost portion of the housing, and the drain pan blocks flow through any gap at the vertically lower portion.

In a method according to this invention, a window air conditioning unit is manufactured with either of two sized evaporators. If a taller sized evaporator is utilized, then a first drain pan sized for the larger size evaporator is utilized. On the other hand, if the shorter sized evaporator is utilized, then an alternative drain pan is utilized which has a surface extending upwardly to block flow around the evaporator coils.

These and other features of the present invention can be best understood from the following specifications and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a somewhat schematic view of a window air conditioning unit according to the present invention.

Figure 2 shows a prior art evaporator assembly.

Figure 3 shows an alternative prior art evaporator assembly.

Figure 4A shows a first embodiment drain pan. Figure 4B is a side view of the first embodiment drain pan and a shorter evaporator.

Figure 5A shows a second drain pan.

Figure 5B shows the second drain pan mounted with a taller evaporator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A window air conditioning unit 120 is illustrated in Figure 1. Window air conditioning unit 120 includes a compressor 122. The compressor 122 compresses a refrigerant and delivers it downstream to a condenser 124. The condenser 124 is positioned adjacent a blower fan 126. Fan 126 moves air over the condenser 124, and cools refrigerant within the condenser. Refrigerant moves from the condenser 124 through an expansion device (not shown), to an evaporator 30. A motor 128 drives the fan 126 and a blower 130. As known, air is drawn in through a grill 132 over the evaporator 30, and into an outlet duct 144, where it is delivered through an outlet opening 142 into the environment to be conditioned. This view is essentially a cross-section and the unit is enclosed in practice.

With a prior art evaporator 30 such as shown in Figure 2, a housing

31 is generally designed to be sized to properly receive the evaporator 30, and the evaporator 30 generally extends from a vertically lower surface of the housing to a vertically upper surface 32 of the housing. As shown, a base 29 of the housing is spaced slightly from a lower part of evaporator 32. Typically, a drain pain is positioned at this location. In this embodiment, the coils are of a somewhat larger size, such that they extend from the upper portion of the housing to the lower portion of the housing. Again, the housing is sized for this taller evaporator 30. In one embodiment, these coils can be formed as 3/8 inch or 5/16 inch tubing.

Figure 3 shows an alternative evaporator 35, wherein smaller tubing 38 is utilized. The smaller tubing 38 could be 7 millimeters. With the 7 millimeter coil there is a clearance space between the vertically upper portion of the housing 31 and the uppermost portion of the evaporator 35. A foam material 36 is disposed into this clearance. In the absence of the foam material, air could pass through the space and bypass the evaporator without being conditioned. This would of course be undesirable.

Of course, the mentioned sizes are simply examples, and other sizes may certainly be used and come within this invention.

The present invention is directed to eliminate the requirement of adding the foam 36. Thus, as shown in Figure 4 A, a first embodiment drain pan 40 has a drain tap 42. As known, the drain tap 42 would direct water in a pan portion 48 rearwardly and to the outside space of the air conditioning unit 120.

As can be seen in Figure 4B₅ an outer lip 44 on the drain pan 40 sits in front of the evaporator. An extension ridge 46 extends upwardly from the collection portion 48 and serves to block the gap created when the smaller sized evaporator 50 is utilized. As shown, an upper end 54 of the evaporator 50 is close to the upper end of the housing 51. The tubing 52 in this embodiment 50 is of the smaller size, but the gap is at the lower end, rather than at the upper end as in the prior art. As shown, the drain pan 40 is positioned beneath the evaporator 50. The ridge 46 is aligned with the evaporator coils such that the gap is blocked in this embodiment. Returning to Figure 4A, there is a leakage portion 49 such that water collected in a forward leakage 47 can flow around the ridge 48 and to the tap 42.

Figure 5 A shows another embodiment 54, having the tap 40, a lip

58, and a collection portion 56. As can be appreciated from Figure 5B, this embodiment is utilized when a taller evaporator embodiment 60 is utilized. The taller embodiment 60 would allow the drain pan to be smaller, and allows the elimination of the ridge 46.

In a method according to this invention, a drain pan 40 or 54 is selected to correspond to the evaporator 50 or 60 which is utilized in any one window air conditioning unit. With the present invention, there is no gap between the evaporator and the housing, and yet no separate assembly process for disposing foam to fill a clearance is required.

While the application is disclosed as an air conditioning system, the invention would also extend fully to a heat pump. In that sense, the term "air conditioning unit" as utilized in this application would also extend to a heat pump which can provide the air conditioning function as well as a heating function. In addition, fluid connections are omitted from the Figure 1 drawing for simplicity sake. A worker of ordinary skill in the art would recognize how to provide appropriate connections.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reasons the following claims should be studied to determine the true scope and content of this invention.

Claims

1. A window air conditioning unit comprising: a compressor; a condenser positioned to be in an outside space and receive refrigerant from the compressor; an evaporator, refrigerant from the condenser moving to the evaporator; and a drain pan positioned beneath the evaporator, and serving to collect water removed from air by the evaporator, the drain pan including a tap to move the water to the outside space, and the drain pan having a generally vertically lower water collection area and a vertically upwardly extending ridge, said ridge extending upwardly to be spaced closely from a vertically lower portion of the evaporator.

2. The window air conditioning unit as set forth in Claim 1, wherein there is an alternative larger size evaporator in alternative units of the window air conditioning unit, and the alternative larger evaporator is utilized with a drain pan that does not include the ridge.

3. The window air conditioning unit as set forth in Claim 1, wherein said drain pan has a pair of water collection spaces at a location vertically lower than said ridge, with a forward water collection space being positioned further from the tap than a main water collection space, and there being a communication groove communicating said forward collection space to said main collection space, and then to said tap.

4. The window air conditioning unit as set forth in Claim 3, wherein a forward lip on the drain pan sits forwardly of the evaporator, and defines the forward collection space with said ridge.

5. The window air conditioning unit as set forth in Claim 1, wherein said evaporator extends vertically upwardly to be closely spaced from a vertically upper inner surface of a housing which receives the window air conditioning unit.

6. A method of assembling a window air conditioning unit comprising the steps of: providing a compressor, said compressor communicating refrigerant to a condenser, said condenser communicating refrigerant to an evaporator, said evaporator being selected from one of two distinct vertical sizes, and providing a pair of drain pans, with a first drain pan being associated with a vertically smaller of said two evaporators, and a second drain pan being associated with a vertically larger of said two evaporators; providing said first drain pan to have a vertically upwardly extending ridge to block a gap between a housing for receiving the window air conditioning unit and said vertically smaller evaporator; assembling said window air conditioning unit in the housing and positioning a selected drain pan beneath said selected evaporator; and pulling air over said evaporator to cool and remove water from the air, collecting water in the selected drain pan, and delivering the water to an outside environment from the drain pan.

7. The method as set forth in Claim 6, wherein said second drain pan is not provided with vertically upwardly extending ridge.

8. The method as set forth in Claim 6, wherein each of said two evaporators are mounted within a housing for the air conditioning unit which is the same size for an air conditioning unit receiving either evaporator, and wherein both of said two evaporators extend to be vertically closely spaced from a vertically uppermost inner space of the housing.