Patent ID: 8422870
Filing Date: 2013-04-16
Classification: F24D,F24H,F25B,Y02B

Abstract:
1. A heat pump water heater comprising: a water storage tank; a heat pump, comprising a sealed system including a compressor an evaporator, a condenser and a refrigerant configured for refrigerant flow from compressor to condenser to evaporator and back to the compressor, wherein the condenser is positioned in a heat exchange relationship with the water storage tank for heating the contents of the tank, wherein the heat pump condenser includes a side portion wrapped around the exterior of the water storage tank side wall and a bottom portion arranged proximate to and in a heat exchange relationship with the bottom wall of the water storage tank, wherein the bottom portion includes the condenser inlet, whereby the refrigerant flows first through the bottom portion of the condenser before flowing through the side portion; a first electric resistance heater positioned proximate the upper region of the water storage tank; a first temperature sensor positioned proximate the top of the water storage tank; and a controller operatively connected to the first temperature sensor and including an event flow module configured to receive and process data representative of temperature readings measured by the first temperature sensor in order to determine if water is flowing from the water storage tank, wherein the controller is operatively connected to the heat pump and the first electric resistance heater, the controller being further configured to automatically select and energize at least one of the heat pump and the first electric resistance heater in response to the temperature readings measured by the first temperature sensor.