"Condensate Drain Hose Arrangement for an Evaporator Unit"

Technical Field

This invention relates generally to evaporator units for air conditioning systems and, more particularly, to a condensate drain arrangement for an evaporator unit that is adaptable to be installed in either a horizontal or a vertical orientation.

Background Art In many air conditioning, heating and ventilating systems, conditioned air is discharged into an internal space through an air distribution or conditioning unit. For example, one general type of air conditioning system, often referred to as a split system, includes separate indoor and outdoor units. The outdoor unit includes a compressor, a heat exchanger and a fan. The indoor unit includes a heat exchanger and a fan and is referred to as an evaporator unit. In operation, the indoor fan draws air into the evaporator unit, through an inlet thereof, and forces the air over the heat exchanger and then out of the evaporator unit, through an outlet opening therein.

The outdoor fan draws outdoor air into the outdoor unit, and circulates it over the outdoor heat exchanger and then back out to ambient. At the same time, a compressor causes a refrigeration fluid to circulate through and between the indoor/outdoor heat exchangers. At the indoor heat exchanger, the refrigerant absorbs heat from the air passing over that heat exchanger to cool the air. At the same time, at the outdoor heat exchanger, the air passing over the heat exchanger absorbs heat from the refrigerant passing therethrough.

Split type air conditioning units of this type are typically manufactured in a wide range of cooling capacities. In manufacturing such units, particularly as the units become larger, the fabrication and assembly of the various components, becomes onerous and cumbersome. Typically, the larger the unit, the more components are required and the more fasteners are required in order to assemble all of the components. It is considered extremely desirable to minimize the number of components and fasteners required in the fabrication and assembly process.

A further benefit to the conditioning of the indoor air which occurs with such an air conditioning unit is the removal of undesired humidity in the air as the air being cooled is passed by the indoor heat exchanger. This dehumidifϊcation results in an accumulation of water as humidity condenses on the cold indoor heat exchanger coils. It is accordingly necessary to collect the removed water and divert it to an appropriate disposal point.

Commonly, the indoor unit of a split system is mounted on the floor of a room against a wall thereof. In some situations, however, it is desirable to place the indoor unit in another location, such as on the ceiling of the room. It should be appreciated that an indoor unit which may be mounted in either of the above-mentioned floor mounted or ceiling mounted positions, while still providing the ability to collect the condensate from the unit, would be extremely desirable.

An indoor unit for an air conditioning system which may be mounted as a floor, ceiling or wall mount is shown and described in U.S. Patent

No. 6,321,556. However, the unit as shown in this patent includes two different condensate collection pans to accommodate the various installation possibilities.

Disclosure of the Invention An evaporator unit for an air conditioning system includes a housing having a back panel and a front section defining an air inlet and an air outlet. The housing defines an airflow path through the unit extending from the inlet to the outlet. An evaporator coil is supported in the housing and within the air flow path. The unit includes an evaporator fan for causing air to flow along the air flowpath and through the evaporator coil where the air is cooled and water is removed therefrom, resulting in condensation.

A single drain pan is provided for collecting condensate with the drain pan being so constructed and oriented that the condensate will collect therein whether the unit is in a vertical orientation or a horizontal orientation. A drainage fixture is attached to the drain pan in such a manner that it is always at a lower elevation then the drain pan when the unit is either in the horizontal or vertical orientation. The housing has an end wall and a back wall with each having an opening therein. Tubing is attached to the drainage element and is selectively passed through one of the openings to provide fluid communication from the drain pan to a location outside of the housing. For installations where gravity alone will not allow drainage from the tubing, a condensate pump is provided. A collecting sump and a sensor are also provided to responsively activate the pump.

Brief Description of the Drawings

Fig. 1 is a perspective view of an evaporator unit in accordance with the present invention.

Fig. 2 is a side view of the evaporator unit as installed on the ceiling.

Fig. 3 is a side view of an evaporator unit as installed at the base of a wall.

Fig. 4 is a perspective end view of the ceiling mounted unit showing the right side thereof with the end cover removed. Fig. 5 is a perspective end view thereof of the lower wall-mounted unit with the end cover removed.

Fig. 6 is a sectional end view of a ceiling mounted unit with a condensate pump.

Fig. 7 is a partial perspective view of a portion of the unit as shown in Fig. 6, with the ump removed.

Fig. 8 is a partial perspective view of a portion of the unit as shown in Fig. 6 with the sump/sensor removed.

Detailed Description of the Invention An evaporator unit embodying the present invention is shown at 11 as being installed with its rear side 12 against a lower portion of the wall, near the floor. As will be seen, such a system may alternatively come as horizontally installed with its rear side 12 against the ceiling of a room. For purposes of description, however, the unit 11 will be described as having a front side 13, top 14, a left end 16, a right end 17 and a bottom 18. On the front side 13 there is included a grill 19 through which the room air is drawn in to be conditioned. At

the top 14 there is an air discharge opening 21 for discharging conditioned air to the room.

Shown in Fig. 2 is an evaporator unit 11 as horizontally installed with its rear side 12 mounted under the ceiling 22 and with its bottom 18 against a side wall 23 of the room. Similarly, in Fig. 3, in the unit 11 is shown in its vertically installed position with its rear side 12 disposed against the wall 23 and with its bottom 18 disposed near the floor 24.

It is recognized that an evaporator unit, in addition to cooling the air, tends to dehumidify the conditioned air by the removal of moisture therefrom. This occurs because of the condensation that tends to form on the relatively cool coil, with the condensation then tending to flow by gravity to a drain pan disposed therebelow. The condensation that collects in the drain pan must therefore be properly disposed of. This is commonly accomplished by channeling the flow of liquid condensate to the outdoors. For either the ceiling mounted unit as shown in Fig. 2 or the wall mounted unit as shown in Fig. 3, this can be best accomplished by way of the condensate tube that is fluidly connected to the drain pan so as to flow through the side wall to the outside or into the side wall and downwardly to an outside exit. In Fig. 2, the condensate tube 26 is shown passing through the bottom 18 of the unit 11. In Fig. 3, the condensate tube 27 is shown passing through the rear side 12 of the unit 11.

Referring now to Fig. 3, the evaporator unit is shown with its right end 17 being exposed, i.e., with its right end cover being removed to show an internal side assembly 28 with some of the internal components, including a

refrigerant connection tube 29 from a line which provides fluid communication to tubes within an internal heat exchanger. The condensate tube 26, which provides for drainage of condensate from a condensate pan when the unit is installed in an under- ceiling position, is interconnected at its internal end to a discharge conduit 31 which, in turn, is fluidly interconnected to the drain pan 32. Here, it will be seen that the unit bottom 18 has an opening 33 formed therein for the passing of the condensate tube 26 therethrough. The opening 33 is provided in all units and can either be used as shown in the Fig. 4 embodiment or it can be left as an open space as shown in Fig. 5 if the condensate flow is routed in a different fashion as shown in Fig. 5.

In the Fig. 5 embodiment, wherein the unit rear side 12 is placed against the side wall of the room, the discharge conduit 31 is again fluidly interconnected to the drain pan 32, but with the tubing 34 fluidly interconnected to an elbow 36 and a horizontal tube 37 passing through an opening 38 in the rear side 12 to fluidly interconnect to the condensate tube 27. The opening 38, like the opening 33, is formed in each of the units that are manufactured and may be either used as shown in the Fig. 5 embodiment or be allowed to remain in the unused position as shown in the Fig. 4 embodiment.

An alternative embodiment of the ceiling mounted unit is shown in Fig. 6 wherein the relationship between the evaporator coil 39 and the drain pan 32 is shown. The drain pan 32 is disposed below the evaporator coil 39 so that the condensate forming on the evaporator coil 39 will flow by gravity to the drain pan 32 and collect in a reservoir 41 from which it drains to the discharge conduit 31 and the tubing 34. In this instance, however, the particular

installation arrangement does not allow for simple drainage by way of gravity flow, and it is therefore necessary to provide a mechanism for pumping the condensate out of the unit and into a drainage system. The tubing 34 is fluidly connected to a sump/sensor, which then fluidly communicates with an inlet tube 43, a pump 44, and exit tube 46 and a discharge tube 47.

In operation, as the condensate collects in the reservoir 41 it passes through the discharge conduit 31 and the tubing 34 to the sump/sensor 42. When the level in the sump/sensor 42 reaches a certain level, a sensor turns on the pump 44 which then draws the condensate through the inlet tube and discharges it from the exit tube 46 so as to be then discharged from the drainage tube 47. As the level of condensate in the sump/sensor is reduced below a certain level, the pump 44 is then automatically turned off and remains off until the level of condensate increases again to the point where the pump 44 is again turned on.

As discussed hereinabove, the most common installation arrangement would not require a sump/sensor 42 or a pump 44. However, in order to facilitate the AJC installation of such a sump/sensor 42 and pump 44 when needed, provision is made to allow for easy installation of these auxiliary units by an installer. This is accomplished by providing support structure on the inner face 48 of the internal side assembly 49 as shown in Fig. 7. Here, a pair of spaced, flexible fingers 51 and 52 are provided to receive the pump 44 therebetween. These flexible fingers 51 and 52 have respective retaining members 53 and 54 projecting inwardly toward each other as shown. To install the pump 44, it is a simple matter to flex the fingers 51 and 52 outwardly to snap on the pump 44 into place, with the retaining members 53 and 54 then holding it

in the installed position.

A different arrangement is shown for installation of the sump/sensor with the supporting structure as shown in Fig. 8. Here, there are provided a plurality of ribs 56, 57 and 58 and a pair of side straps 59 and 61 for collectively cradling the underside of the sump/sensor 42. A strap or other similar fastener 62 is then provided to wrap around the sump/sensor 42 to secure it in its installed position.