The present invention is directed to a condensate drain pan for use under the heat exchange coil of an HVAC or refrigeration system. More specifically, the condensate drain pan is multi-functional in that it includes a bottom outlet and a side outlet and in that either outlet can be used on either end of an air conditioning cabinet.
In recent years, the air conditioning industry has had a heightened awareness of indoor air quality, particularly relating to the potential health concerns deriving from microbial growth in standing condensate. This standing condensate remains in the drain pans during the air conditioning unit's off cycle, and may be subsequently transported to an occupied space by way of the indoor air stream. For this reason, the air conditioning industry has recognized the need for a periodic cleaning of drain pans. Drain pans are positioned under a condensing heat exchange coil to collect the condensate as that condensate condenses and drips off the coil.
Typical past industry practice has provided a flat condensate pan with condensate connections at only one end of the drain pan. In installing such drain pans, particularly in retrofit applications, it is not uncommon for the air conditioning unit to be improperly leveled during installation. If an air conditioning unit is improperly leveled such that the slope of the unit is away from the single drain pan connection, condensate will pool at the end of the drain pan opposite the drain connection. In more extreme cases, condensate will overflow the drain pan resulting in unwanted water in the base of the air conditioning unit and, potentially, in the occupied space and structure. Past solutions to this situation have included (a) removal of the air conditioning unit and re-leveling of the mounting curb at great expense, or (b) if the unit is large enough, providing a connection at either end of the drain pan. In many cases, the problem is simply ignored due to the difficulty in correcting the problem.
Furthermore, access for cleaning of drain pans in the past has typically been through a time consuming removal of the exterior panels of the air conditioning units, followed by an attempt to clean the drain pan through a limited access aperture. As a result, the drain pan was often not cleaned, or was improperly cleaned. In some cases, chemical "pills" to counteract microbial growth have been added to drain pans in lieu of full drainage and proper cleaning.
Industry standards have been under development that make it unacceptable to provide air conditioning unit designs that allow condensate to pool in drain pans. The practical industry response to this has been to provide drain pans with sloped surfaces to ensure complete drainage. However, this assumes that the air conditioning units are properly leveled. With a sloped drain pan there is no longer a way to provide connections on both ends of the drain pan without one end of the drain pan being dysfunctional, thereby eliminating the second solution above and leaving only the solution of incurring the expense of re-leveling the air conditioning unit if the unit is improperly installed.
Regarding bottom condensate connections, it is becoming common practice in the building/roofing industry to eliminate as many roof penetration apertures as possible due to the substantial warranties and potential liabilities associated with roof leaks in that industry. As such, there is a growing preference to bring the condensate disposal piping of the air conditioning unit from the space up through the bottom of the unit to eliminate a roof penetration and a potential leak related liability. Solutions to date have been (a) to route condensate piping out of the side of the unit and back in through the side of the rooftop curb, or (b) to provide both bottom and side outlet connections, requiring whichever outlet connection is not in use to be plugged or capped with a potential for leaks, or (c) to mount the drain pan in an elevated position within an air conditioning unit such that the piping could be routed out either the side or through the base of the unit.
It would be desirable to provide a drain pan which is easily cleanable, which is sloped, which can be installed from either side, and which includes both a bottom outlet and a side outlet.