Heat pump and burner combination water heating systems and methods for providing instantaneous and constant hot water

Abstract

Systems, methods, and apparatuses for heating water are provided herein. A water heating system is disclosed, which includes a burner, a vapor-compression cycle system, and a water line in communication with the burner and the vapor-compression cycle system. The water heating system may be a tankless, or on demand, water heating system. Water within the water line may be initially heated by the vapor-compression cycle system before the water enters the burner. In this manner, the water may be preheated using the vapor-compression cycle system before the water is further heated by the burner.

What is claimed is: 
     
         1 . A water heating system, comprising:
 a burner;   a vapor-compression cycle system; and   a water line in communication with the burner and the vapor-compression cycle system.   
     
     
         2 . The water heating system of  claim 1 , wherein the water line comprises a water inlet line and a water outlet line, wherein the water inlet line is in communication with the vapor-compression cycle system upstream of the burner. 
     
     
         3 . The water heating system of  claim 2 , further comprising a bypass line connecting the water inlet line and the water outlet line. 
     
     
         4 . The water heating system of  claim 3 , further comprising a bypass valve disposed on the bypass line. 
     
     
         5 . The water heating system of  claim 2 , wherein the vapor-compression cycle system comprises a condenser and an evaporator. 
     
     
         6 . The water heating system of  claim 5 , wherein the condenser is in communication with the water inlet line to exchange heat with water within the water line. 
     
     
         7 . The water heating system of  claim 5 , wherein the burner comprises a primary heat exchanger, a secondary heat exchanger, and a vent. 
     
     
         8 . The water heating system of  claim 7 , wherein the evaporator is in communication with the burner to exchange heat with gas within the burner. 
     
     
         9 . The water heating system of  claim 7 , wherein the water inlet line is in communication with the secondary heat exchanger to exchange heat with the water within the water line after the water exchanges heat with the condenser. 
     
     
         10 . The water heating system of  claim 9 , wherein the water line is in communication with the primary heat exchanger to exchange heat with the water within the water line after the water exchanges heat with the secondary heat exchanger. 
     
     
         11 . The water heating system of  claim 7 , wherein the water outlet line exits the primary heat exchanger. 
     
     
         12 . A method for heating water, comprising:
 exchanging heat with water in a water line with a vapor-compression cycle system; and then   exchanging heat with the water in the water line with a burner.   
     
     
         13 . The method of  claim 12 , further comprising bypassing the vapor-compression cycle system and the burner with a bypass line connecting a water inlet line of the water line and a water outlet line of the water line. 
     
     
         14 . The method of  claim 12 , further comprising exchanging heat between a condenser of the vapor-compression cycle system and an inlet water line of the water line. 
     
     
         15 . The method of  claim 14 , further comprising exchanging heat between a secondary heat exchanger of the burner with the water within the water line after the water exchanges heat with the condenser. 
     
     
         16 . The method of  claim 15 , further comprising exchanging heat between a primary heat exchanger of the burner with the water within the water line after the water exchanges heat with the secondary heat exchanger. 
     
     
         17 . The method of  claim 12 , further comprising exchanging heat between an evaporator of the vapor-compression cycle system and gas within the burner. 
     
     
         18 . A water heating system, comprising:
 a burner comprising at least one heat exchanger;   a vapor-compression cycle system comprising at least one heat exchanger; and   a water line in communication with the at least one heat exchanger of the vapor-compression cycle system and the at least one heat exchanger of the burner,   wherein the at least one heat exchanger of the vapor-compression cycle system is in communication with the water line and exchanges heat between water in the water line and a refrigerant of the vapor-compression cycle system prior to exchanging heat between the water in the water line and gas in the at least one heat exchanger of the burner.   
     
     
         19 . The water heating system of  claim 18 , further comprising a bypass line connecting a water inlet line and a water outlet line of the water line. 
     
     
         20 . The water heating system of  claim 19 , further comprising a bypass valve disposed on the bypass line.