Heated Water Storage Tank with Integral Trapped Air to Mitigate Expansion/Contraction

Abstract

A water tank as part of a system that limits the pressure in the system and eliminates the need for a separate expansion tank. The water tank includes a hot water pipe with an inlet positioned a first distance below the top of the water tank, the first distance is determined so that the volume above the hot water pipe inlet exceeds a volume that water in the tank will expand when changing from a first low temperature to a second higher temperature. In a closed loop hydronic system embodiment, when dissolved air in the water separates, the separated air is caught by the volume of air at the top of the water tank which prevents the separated air from traveling through the closed loop system.

What is claimed is: 
     
         1 . A storage device for holding and heating water, comprising:
 a container designed to hold a first amount of water, having a side, a floor and a ceiling;   a first pipe having a first outlet positioned within said container for bringing cold water into said container;   a second pipe having a first inlet positioned within said container at a level above said first outlet, for transferring heated water out of said container, said first pipe passing through said ceiling; and   a heating device for heating the water in said container;   wherein said first inlet is positioned at a first distance from said ceiling such that a first volume of said container being the volume between said first inlet and said ceiling exceeds a second volume being a difference in volume between said first amount of water at a first temperature and said first amount of water at a second temperature.   
     
     
         2 . The storage device of  claim 1 , further comprising seals between said container and the first and second pipes prevent air from leaving said container through said seals. 
     
     
         3 . The storage device of  claim 1 , wherein the storage device receives water from said first pipe at a temperature at or above said first temperature. 
     
     
         4 . The storage device of  claim 1 , wherein the storage device heats the water to a temperature at or below said second temperature. 
     
     
         5 . The storage device of  claim 1 , wherein no portion of said container substantially moves in response to a pressure changes within said container. 
     
     
         6 . The storage device of  claim 1 , further comprising a water level indicator. 
     
     
         7 . The storage device of  claim 6 , said water level indicator includes:
 a tube having a closed end, an open end, and a transparent portion;   an indicator device, positioned in said open end and in said transparent portion to identify the water level in said container.   
     
     
         8 . The storage device of  claim 7 , said indicator device having:
 a floating device positioned in said open end;   an extender having an portion visible in the transparent portion and coupled to said floating device, the position of the extender indicative of the water level in said container.   
     
     
         9 . The storage device of  claim 6 , further comprising a valve for at least one of releasing air from said container or adding air to said container. 
     
     
         10 . The storage device of  claim 6 , further comprising a pressure gauge to identify the air pressure in said container. 
     
     
         11 . The storage device of  claim 10 , further comprising a valve for at least one of releasing air from said container or adding air to said container. 
     
     
         12 . The storage device of  claim 6 , said water level indicator including:
 a first opening positioned below the level of said first inlet;   a second opening positioned above a water level in said container;   a transparent portion, between said first and second openings, wherein the water level is visible when the water level is above the first opening.   
     
     
         13 . The storage device of  claim 12 , wherein said water level indicator further comprises a valve for at least one of releasing air from said container or adding air to said container. 
     
     
         14 . The storage device of  claim 12 , wherein said water level indicator further comprises a pressure gauge to identify the air pressure in said container. 
     
     
         15 . The storage device of  claim 14 , wherein said water level indicator further comprises a valve for at least one of releasing air from said container or adding air to said container. 
     
     
         16 . The storage device of  claim 12 , wherein said first and second openings are connected to the container and include water level indicator seals that prevent air from escaping the combination of said container and water level indicator. 
     
     
         17 . A closed loop hydronic system comprising:
 a storage device for holding and heating water, comprising:
 a container designed to hold a first amount of water, having a side, a floor and a ceiling; 
 a first pipe having a first outlet positioned within said container for bringing water into said container; 
 a second pipe having a first inlet positioned within said container at a first inlet level above said first outlet, for transferring heated water out of said container, said first pipe passing through said ceiling, said water level in the container being above said first inlet level; and 
 a heating device for heating the water in said container; 
 wherein said first inlet is positioned at a first distance from said ceiling such that a first volume of said container being the volume between said first inlet and said ceiling exceeds a second volume being a difference in volume between said first amount of water at a first temperature and said first amount of water at a second temperature. 
   
     
     
         18 . The system of  claim 17 , wherein air bubbles in the closed loop system are collected into said first volume. 
     
     
         19 . The system of  claim 17 , wherein air in said first volume limits the pressure in the closed loop system and eliminates a need for an expansion tank external to said container in the closed loop system. 
     
     
         20 . The system of  claim 17 , further comprising a water level indicator to provide an indication of said water level in said container. 
     
     
         21 . The system of  claim 20 , further comprising a valve for at least one of releasing air from said container or adding air to said container. 
     
     
         22 . The system of  claim 21 , wherein if said water level in said container approaches said first inlet level, air can be removed from the system using said valve. 
     
     
         23 . The system of  claim 20 , further comprising a pressure gauge to identify the air pressure in said container. 
     
     
         24 . The system of  claim 20 , said water level indicator includes:
 a tube having a closed end, an open end, and a transparent portion;   an indicator device, positioned in said open end and in said transparent portion to identify the water level in said container.   
     
     
         25 . The system of  claim 21 , said indicator device having:
 a floating device positioned in said open end;   an extender having an portion visible in the transparent portion and coupled to said floating device, the position of the extender indicative of the water level in said container.   
     
     
         26 . The system of  claim 20 , said water level indicator including:
 a first opening positioned below the level of said first inlet;   a second opening positioned above a water level in said container;   a transparent portion, between said first and second openings, wherein the water level is visible when the water level is above the first opening