Hybrid water heater

A heat pump water heater, comprising:

• a tank having a tank wall that defines a volume;
• a housing disposed adjacent the tank, wherein the housing comprises:
• a top plate forming an air inlet aperture therethrough,
• a first side wall forming an air outlet aperture therethrough,
• a second sidewall proximate the air inlet aperture, and
• a metal grill covering the air inlet aperture, wherein the metal grill is configured to prevent unwanted objects from entering the air inlet aperture without obstructing air flow therethrough;
• a heat source disposed with respect to the volume to convey heat to water in the tank;
• a refrigerant conduit that defines at least part of a closed refrigerant path;
• a pump disposed proximate the tank and in fluid communication with the refrigerant conduit so that the pump is part of the refrigerant path and, when operative, pumps refrigerant through the closed refrigerant path, wherein a portion of the refrigerant conduit is in thermal communication with the volume so that refrigerant flowing through the refrigerant path transfers heat to water in the volume;
• a coil defined by the refrigerant conduit, wherein the coil is within the housing;
• a fan within the housing, aligned with the air outlet aperture, and disposed with respect to an evaporator coil so that operation of the fan moves an air flow across the evaporator coil;
• a temperature sensor in thermal communication with the refrigerant conduit to thereby detect temperature of refrigerant in the refrigerant conduit;
• a controller in communication with the temperature sensor so that the controller receives signals from the temperature sensor corresponding to temperature of the refrigerant, wherein the controller is configured to control a speed of the fan in response to temperature of the refrigerant.