Heat pump water heater in conjunction with gas water heater

Abstract

A method for heating water delivered and stored in a water heater storage tank includes activating at least one of dual fuel heater types in response to various modes of operation. The water heater is preferably a dual fuel or hybrid heat pump gas water heater that includes a heat pump as the first type of heater for heating the water, and a gas burner as the second type of heater that transfer heat to the water. One or more sensors monitor water temperature and communicate with a controller to activate one of, or both of, the first and second types of heaters. If there is an electrical power outage, the hybrid heat pump gas water heater is still able to heat the water.

1 . A water heater, comprising:
 a tank body for storing a volume of associated water, including:
 a cold water supply line for delivering associated water to the tank body, and, 
 a water discharge line for egress of heated associated water from the tank body; 
 a first type of heater for heating the associated water in the tank body; and, 
 a second type of heater having a different energy/fuel source than the first heater type for heating the associated water. 
   
     
     
         2 . The water heater of  claim 1 , wherein the first heater type includes a heat pump. 
     
     
         3 . The water heater of  claim 2 , wherein the heat pump includes:
 an evaporator;   a compressor operatively associated with the evaporator;   a condenser for transferring heat thereto;   a restriction, and
 a fan operatively associated with the evaporator for directing ambient air over the evaporator and transferring heat thereto. 
   
     
     
         4 . The water heater of  claim 3 , wherein the condenser is wrapped around an outer surface of the tank body. 
     
     
         5 . The water heater of  claim 1 , wherein the second heater type is a gas burner. 
     
     
         6 . The water heater of  claim 5 , wherein the gas burner assembly is situated at and heats a base portion of the tank body. 
     
     
         7 . The water heater of  claim 5 , wherein the gas burner assembly is situated proximate to the tank body. 
     
     
         8 . The water heater of  claim 1 , further including:
 at least one sensor for measuring a temperature of the associated water stored in the tank body; and,   a controller receiving a signal from the at least one sensor indicative of associated water temperature; and,   the controller actuates at least one of the first and second heaters in response to the sensed temperature.   
     
     
         9 . The water heater of  claim 1  wherein one of the first and second heater types is operational in the event of an electrical power outage. 
     
     
         10 . A method of heating water, comprising:
 delivering water to a tank body through a water supply line;   storing a volume of the water in the tank body;   heating the water in the tank body with a first type of heater; and,   selectively using a second type of heater having a different energy/fuel source than the first heater type to heat the water when a threshold is met.   
     
     
         11 . The method of  claim 10 , further including using a heat pump assembly for the first heater type. 
     
     
         12 . The method of  claim 11 , further including using a gas burner assembly for the second heater type. 
     
     
         13 . The method of  claim 10 , wherein a first heater type heats the water to a preselect temperature, and a second heater type supplements heating of the water. 
     
     
         14 . The method of  claim 10 , wherein the first heater type is a heat pump and the second heater type is a gas burner assembly. 
     
     
         15 . A water heater, comprising:
 a tank body for storing a volume of associated water, including:
 a cold water supply line for delivering associated water to the tank body, and, 
 a water discharge line for egress of heated associated water from the tank body; 
   a heat pump for heating the associated water in the tank body with an associated working fluid that circulates through the heat pump, including:
 an evaporator, 
 a compressor, 
 a condenser for transferring heat to the associated water stored in the tank body, 
 a throttling device, and, 
 a fan for directing air over the evaporator and transferring heat from the air to the associated working fluid in the evaporator; and, 
   a gas burner assembly for heating the associated water;   at least one sensor for measuring a temperature of associated water stored in the tank body; and,   a controller receiving a signal indicative of the temperature of the associated water and selectively using the heat pump and/or gas burner.   
     
     
         16 . The water heater of  claim 15 , wherein the controller actuates the gas burner assembly if a relative temperature change over a preselect time period exceeds a threshold value. 
     
     
         17 . The water heater of  claim 15 , wherein the condenser is received around an outer surface of the tank body. 
     
     
         18 . The water heater of  claim 15 , wherein the gas burner assembly is situated at and heats a base portion of the tank body. 
     
     
         19 . The water heater of  claim 15 , wherein the gas burner assembly is situated proximate to a surface of the tank body. 
     
     
         20 . The water heater of  claim 15  further comprising a demand response module for communicating with an associated utility, and a controller that receives data input from the water heater and the utility to determine a desired operation of the water heater. 
     
     
         21 . The water heater of  claim 15  wherein the condenser is either located remotely and water from the tank body is recirculated via a pump or via natural convection to the condenser and back to the tank body, or the condenser is in direct contact with water in the tank body.