Heat pump water heaters are gaining broader acceptance as a more economic and ecologically-friendly alternative to electric water heaters. These systems utilize a condenser configured in a heat exchange relationship with a water storage tank, for example wrapped around the tank in a series of coils. During operation of the vapor compression heat pump cycle, air flows across an evaporator and transfers energy to a refrigerant flowing through the evaporator. As such, the refrigerant exits the evaporator as a superheated vapor and/or high quality vapor mixture. Upon exiting the evaporator, the refrigerant enters a compressor where the pressure and temperature increase and the refrigerant becomes a superheated vapor. The superheated vapor from the compressor then enters the condenser, wherein the superheated vapor transfers energy to the water within a storage tank and returns to a saturated liquid and/or high quality liquid vapor mixture.
As heat is absorbed from the air flowing over evaporator, condensation forms which must be collected and discharged. Conventional heat pump water heaters rely on gravity to move collected condensate away from the heat pump water heater. However, this requires a user of such a water heater appliance to provide other means for disposing of the collected water, particularly when the water heater appliance is installed below ground level. For example, a user may need to install a pump and/or complicated drainage system to ensure that the collected water is discharged to a suitable drain.
Accordingly, a heat pump water heater appliance with features for disposing of collected condensate would be useful. More specifically, a heat pump water heater appliance having an integral means for discharging collected condensate with little user intervention would be particularly beneficial.