Water heater with insulating layer

Abstract

A water heater includes: an inner tank having an internal cavity configured to hold water therein; a heating device residing in the internal cavity; an outer lining that surrounds the inner tank, a gap being present between the outer lining and the inner tank; and insulation material located in the gap. The gap is under a vacuum of between about 5 and 200 microns. In this configuration, the water heater can have an R value in excess of 500. With this level of insulative capacity, water stored in the water heater may lose only 2° F. or less over a 24 hour period, thereby substantially outperforming conventional water heaters.

1 . A water heater, comprising:
 an inner tank having an internal cavity configured to hold water therein;   a heating device residing in the internal cavity;   an outer lining that surrounds the inner tank, a gap being present between the outer lining and the inner tank; and   insulation material located in the gap;   wherein the gap is under a vacuum of between about 5 and 200 microns.   
     
     
         2 . The water heater defined in  claim 1 , wherein the insulation material comprises ceramic microspheres. 
     
     
         3 . The water heater defined in  claim 1 , wherein the outer lining comprises an inner layer and an outer layer. 
     
     
         4 . The water heater defined in  claim 3 , wherein the inner layer comprises one of a thin metallic foil and a thin layer of ceramic microspheres. 
     
     
         5 . The water heater defined in  claim 3 , wherein outer layer comprises one of a thermoplastic or a metal. 
     
     
         6 . The water heater defined in  claim 3 , wherein the outer layer comprises a thermoplastic and the inner layer comprises a thin layer of microspheres. 
     
     
         7 . The water heater defined in  claim 6 , wherein the outer layer is injection-molded and the inner layer is bonded to the outer layer during injection molding. 
     
     
         8 . The water heater defined in  claim 1 , further comprising supports in the gap to maintain the gap. 
     
     
         9 . The water heater defined in  claim 1 , wherein the outer lining has a two-piece construction. 
     
     
         10 . A water heating system, comprising:
 a heat exchange fluid (HEF) tank;   one or more solar panels;   a first line fluidly connecting the HEF tank with the solar panels;   a water heater, the water heater including a heat exchanger;   a second line fluidly connecting the HEF tank with the heat exchanger;   a third line fluidly connecting the solar panels with the heat exchanger; and   a pump located on one of the first, second or third lines.   
     
     
         11 . The water heating system defined in  claim 10 , wherein the water heater comprises:
 an inner tank having an internal cavity configured to hold water therein;   a heating device residing in the internal cavity;   an outer lining that surrounds the inner tank, a gap being present between the outer lining and the inner tank; and   insulation material located in the gap;   wherein the gap is under a vacuum of between about 5 and 200 microns.   
     
     
         12 . The water heating system defined in  claim 10 , further comprising a fourth line fluidly connecting the first and second lines to isolate the HEF tank from the solar panels, the pump and the heat exchanger. 
     
     
         13 . The water heating system defined in  claim 10 , further comprising a fifth line fluidly connecting the first and third lines to isolate the solar panels from the HEF tank, the pump and the heat exchanger. 
     
     
         14 . The water heating system defined in  claim 10 , further comprising a sixth line fluidly connected to the second line and the third line to isolate the heat exchanger from the solar panels, the pump and the HEF tank. 
     
     
         15 . The water heating system defined in  claim 10 , further comprising a seventh line fluidly connected to two points on the second line, the seventh line providing a cooling loop for fluid in the second line. 
     
     
         16 . A water heating system, comprising:
 a heat exchange fluid (HEF) tank;   one or more solar panels;   a first line fluidly connecting the HEF tank with the solar panels;   a water heater, the water heater including a heat exchanger;   a second line fluidly connecting the HEF tank with the heat exchanger, wherein one of the first line and the second line includes a first valve, and wherein the second line includes a second valve;   a third line fluidly connecting the solar panels with the heat exchanger, the third line including a third valve;   a pump located on one of the first, second or third lines; and   a controller operably associated with the first, second and third valves.   
     
     
         17 . The water heating system defined in  claim 16 , further comprising a fourth line fluidly connecting the first and second lines to isolate the HEF tank from the solar panels, the pump and the heat exchanger, the fourth line including a fourth valve operably associated with the controller. 
     
     
         18 . The water heating system defined in  claim 17 , further comprising a first thermocouple associated with the HEF tank, and wherein the controller is configured to close the first valve and open the fourth valve if the first thermocouple detects a temperature above a predetermined threshold. 
     
     
         19 . The water heating system defined in  claim 16 , further comprising a fifth line fluidly connecting the first and third lines to isolate the solar panels from the HEF tank, the pump and the heat exchanger, the fifth line including a fifth valve operably associated with the controller. 
     
     
         20 . The water heating system defined in  claim 19 , further comprising a second thermocouple associated with the first line, and wherein the controller is configured to close the third valve and open the fifth valve if the second thermocouple detects a temperature below a predetermined threshold. 
     
     
         21 . The water heating system defined in  claim 16 , further comprising a sixth line fluidly connected to the second line and the third line to isolate the heat exchanger from the solar panels, the pump and the HEF tank, the sixth line including a sixth valve operably associated with the controller. 
     
     
         22 . The water heating system defined in  claim 21 , further comprising a third thermocouple associated with the water heater, and wherein the controller is configured to close the second valve and open the sixth valve if the third thermocouple detects a temperature above a predetermined threshold. 
     
     
         23 . The water heating system defined in  claim 16 , further comprising a seventh line fluidly connected to two points on the second line, the seventh line including a seventh valve operably associated with the controller and providing a cooling loop for fluid in the second line.