Non-stratified heat pump water heater and method of making

Abstract

An improved non-stratified heat pump water heater wherein the condenser assembly of the heat pump has at least one non-vertical section and is inserted into the water tank through an existing opening in the top of the tank. The condenser assembly has either a tube-in-a-tube style or U-tube style elongated heat exchanger construction. As the refrigerant condenses along the interior surface of the condenser assembly, the heat from the refrigerant is transferred to the water. Two embodiments of the invention include a water heater having a separate sacrificial anode rod and a water heater wherein the condenser assembly acts not only as a heat exchanger but also as the sacrificial anode in the water tank by being constructed of a metal which is more likely to corrode than the metal of the tank.

What is claimed is:  
     
         1 . An improved non-stratified heat pump water heater of the type having a water tank with an exterior surface and defining a water chamber, a top on the water tank with at least one opening therethrough in communication with the water chamber, a heat pump of the type having a compressor, the compressor being in fluid communication with a condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit, the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit and control means therefor, the improvement comprising: 
 a condenser assembly having at least one non-vertical section that is disposed through the opening in the top of the water tank and into the water chamber, the condenser assembly comprising an elongate outer body having a closed bottom end and an open and opposed upper end in flow communication with the first refrigerant conduit and an elongate inner body disposed within the outer body and having an open bottom end and a closed and opposed top end in flow communication with the second refrigerant conduit.    
     
     
         2 . An improved non-stratified heat pump water heater as claimed in    claim 1    wherein the compressor, the first refrigerant conduit, the expansion device, the second refrigerant conduit, the expansion valve, the evaporator, the third refrigerant conduit, the fourth refrigerant conduit and the control means are disposed on the water tank.  
     
     
         3 . An improved non-stratified heat pump water heater as claimed in    claim 1    and further comprising a housing disposed on the top of the water tank and containing therein the compressor.  
     
     
         4 . An improved non-stratified heat pump water heater as claimed in    claim 1   , wherein the water tank is constructed of a first metal and wherein the outer body is constructed of a second metal which is capable of corroding at a rate greater than the rate of corrosion of the first metal.  
     
     
         5 . An improved non-stratified heat pump water heater as claimed in    claim 4    wherein the second metal is selected from the group consisting of aluminum, magnesium or zinc.  
     
     
         6 . An improved non-stratified heat pump water heater as claimed in    claim 4    wherein the inner body is formed of copper.  
     
     
         7 . An improved non-stratified heat pump water heater as claimed in    claim 1    wherein the outer body and the inner body are constructed of copper.  
     
     
         8 . An improved non-stratified heat pump water heater of the type having a water tank with an exterior surface and being formed of a first metal and defining a water chamber, a top on the water tank with at least one opening therethrough for an anode rod to be disposed within the water chamber and a heat pump of the type having a compressor being in fluid communication with a condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit, the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit and control and means therefor, the improvement comprising: 
 a condenser assembly having at least one non-vertical section comprising an outer body formed of a second metal capable of corroding at a rate greater than the rate of corrosion of the first metal and having a closed bottom, an opposed upper end which is in flow communication with the first refrigerant conduit and an inner body disposed within the outer body and having an open bottom and an opposed top which is in flow communication with the second refrigerant conduit.    
     
     
         9 . An improved non-stratified heat pump water heater as claimed in    claim 8    wherein the compressor, the first refrigerant conduit, the expansion valve, the second refrigerant conduit, the expansion valve, the evaporator, the third refrigerant conduit and the fourth refrigerant conduit are disposed on the water tank.  
     
     
         10 . An improved non-stratified heat pump water heater as claimed in    claim 8    wherein the second metal is selected from the group consisting of aluminum, magnesium or zinc.  
     
     
         11 . An improved non-stratified heat pump water heater as claimed in    claim 8    wherein the inner body is formed of copper.  
     
     
         12 . A condenser assembly for an improved non-stratified heat pump water heater of the type having a water tank with an exterior surface and defining a water chamber, a top on the water tank with at least one opening therethrough in communication with the water chamber, a heat pump of the type having a compressor, the compressor being in fluid communication with a condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit, the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit and control means therefor, the improvement comprising: 
 a condenser assembly having at least one non-vertical section that is disposed through the opening in the top of the water tank and into the water chamber, the condenser assembly comprising an elongate outer body having a closed bottom end and an open and opposed upper end in flow communication with the first refrigerant conduit and an elongate inner body disposed within the outer body and having an open bottom end and a closed and opposed top end in flow communication with the second refrigerant conduit.    
     
     
         13 . A condenser assembly for an improved non-stratified heat pump water heater of the type having a water tank with an exterior surface and being formed of a first metal and defining a water chamber, a top on the water tank with at least one opening therethrough for an anode rod to be disposed within the water chamber and a heat pump of the type having a compressor being in fluid communication with the condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit, the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit, the improvement comprising: 
 a condenser assembly having at least one non-vertical section comprising an outer body formed of a second metal capable of corroding at a rate greater than the rate of corrosion of the first metal and having a closed bottom, an opposed upper end which is in flow communication with the first refrigerant conduit and an inner body disposed within the outer body and having an open bottom and an opposed top which is in flow communication with the second refrigerant conduit.    
     
     
         14 . An improved non-stratified heat pump water heater as claimed in    claim 13    wherein the second metal is selected from the group consisting of aluminum, magnesium or zinc.  
     
     
         15 . An improved non-stratified heat pump water heater as claimed in    claim 13    wherein the inner body is formed of copper.  
     
     
         16 . A method of constructing a non-stratified heat pump water heater of the type having a water tank formed of a first metal and defining a water chamber, a top on the water tank with at least one opening therethrough for an anode rod to be disposed within the water chamber and a heat pump of the type having a compressor being in fluid communication with a condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit, the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit and control means therefor, comprising the steps of: 
 a. removing the anode rod from the water tank; and    b. inserting through the opening the condenser assembly, having at least one non-vertical section, wherein the condenser assembly comprises an outer body formed of a second metal capable of corroding at a rate greater than the rate of corrosion of the first metal and having a closed bottom, an opposed upper end which is in flow communication with the first refrigerant conduit and an inner body disposed within the outer body and having an open bottom and an opposed top which is in flow communication with the second refrigerant conduit, whereby heat from the refrigerant in the first refrigerant conduit is transferred through the outer body to the water in the water tank and the refrigerant then travels through the inner body into the second refrigerant line.    
     
     
         17 . A method of constructing a non-stratified heat pump water heater of the type having a water tank defining a water chamber, a top on the water tank with at least one opening therethrough and a heat pump of the type having a compressor being in fluid communication with a condenser assembly via a first refrigerant conduit, the condenser assembly being in fluid communication with an expansion device through a second refrigerant conduit, the expansion device being in fluid communication with an evaporator through a third refrigerant conduit and the evaporator being in fluid communication with the compressor through a fourth refrigerant conduit and control means therefor, comprising the steps of: 
 a. inserting through the opening the condenser assembly, having at least one non-vertical section, wherein the condenser assembly comprises an outer body and having a closed bottom, an opposed upper end which is in flow communication with the first refrigerant conduit and an inner body disposed within the outer body and having an open bottom and an opposed top which is in flow communication with the second refrigerant conduit, and    b. disposing within a housing on the top of the water tank the compressor, first refrigerant conduit expansion device, second refrigerant conduit evaporator, third refrigerant conduit, and fourth refrigerant conduit and control means, whereby heat from the refrigerant in the first refrigerant conduit is transferred through the outer body to the water in the water tank and the refrigerant then travels through the inner body into the second refrigerant line.