Flexible Graphite Flooring Heat Spreader

Abstract

A floor heating system includes a flooring substrate having a heating or cooling element in heat transfer relationship therewith. A heat spreader is in heat transfer relationship with the flooring substrate. The heat spreader includes a layer of flexible graphite material. A floor covering overlies the layer of flexible graphite material. Temperature variations across an exposed surface of the floor covering are reduced by the presence of the flexible graphite heat spreader, thus providing an improved and more uniform heating to the floor and to the room with which the floor is associated.

What is claimed is: 
     
         1 . A method of heating a space of a building having a planar boundary structure including a structure substrate and a heat element in heat transfer relationship with the structure substrate comprising:
 (a) positioning a heat spreader in heat transfer relationship with the heating element and the structure substrate, wherein the heat spreader comprises a layer of compressed particles of exfoliated graphite having an in-plane thermal conductivity of at least 240 W/m° C., wherein said heat spreader is thermally anisotropic, so that thermal conductivity parallel to the planar boundary structure is greater than the thermal conductivity normal to the planar boundary structure; and   (b) providing heat energy to the heat spreader from said heating element.   
     
     
         2 . The method of  claim 1 , which further comprises unrolling a roll of compressed particles of exfoliated graphite to cover said structure substrate and thereby provide said heat spreader. 
     
     
         3 . The method of  claim 1 , wherein said heat spreader overlies said structure. 
     
     
         4 . The method of  claim 1 , wherein: said layer of compressed particles of exfoliated graphite has a density greater than 0.6 g/cc. 
     
     
         5 . The method of  claim 1 , wherein: said heating element comprises an electrical resistance wiring heating element. 
     
     
         6 . The method of  claim 1 , wherein: said structure substrate comprises a layer of cement in which said heating element is embedded. 
     
     
         7 . The method of  claim 1 , wherein: said structure substrate comprises a layer of thin set mortar in which said heating element is embedded. 
     
     
         8 . The method of  claim 1 , wherein: said heating element comprises a tubing network for carrying a heat transfer fluid. 
     
     
         9 . The method of  claim 8 , wherein: said structure substrate comprises a wooden sub floor to which the tubing network is attached. 
     
     
         10 . A flooring heating system for a flooring substrate, comprising:
 a heating element in heat transfer relationship with said flooring substrate;   a heat spreader, in heat transfer relationship with said flooring substrate, said heat spreader including a flexible sheet of compressed particles of exfoliated graphite, wherein said sheet of compressed particles of exfoliated graphite has two opposed major planar surfaces and said sheet has a first heat conductivity parallel to said planar surfaces and a second heat conductivity normal to said planar surfaces, a ratio of said first heat conductivity to said second heat conductivity defining an anisotropic ratio of at least about 30;   a floor covering overlying said sheet layer of compressed particles of exfoliated graphite, whereby temperature variations across an exposed surface of said floor covering are reduced by the presence of said layer of compressed particles of exfoliated graphite.   
     
     
         11 . The flooring system of  claim 10 , wherein said sheet of flexible compressed particles of exfoliated graphite overlies said flooring substrate. 
     
     
         12 . The flooring system of  claim 10 , wherein said anisotropic ratio is between about 30 and about 250. 
     
     
         13 . The flooring system of  claim 10 , wherein said heat conductivity normal to said planar surfaces is at least about 2 W/m° C. 
     
     
         14 . The system of  claim 14 , wherein said sheet layer of compressed particles of exfoliated graphite has a density of at least about 0.6 g/cc. 
     
     
         15 . The system of  claim 10 , wherein said sheet layer of compressed particles of exfoliated graphite is impregnated with resin. 
     
     
         16 . The flooring system of  claim 10 , wherein said heating element comprises an electrical resistance wiring heating element. 
     
     
         17 . The flooring system of  claim 10 , wherein said flooring substrate comprises a layer of cement in which said heating element is embedded; and said floor covering is selected from the group consisting of vinyl and carpet. 
     
     
         18 . The flooring system of  claim 10 , wherein said flooring substrate comprises a layer of thin set mortar in which said heating element is embedded; and
 said floor covering comprises ceramic tile.   
     
     
         19 . The flooring system of  claim 10 , wherein said heating element comprises a tubing network for carrying a heat transfer fluid. 
     
     
         20 . The flooring system of  claim 19 , wherein said flooring substrate comprises a wooden sub floor to which the tubing network is attached. 
     
     
         21 . The flooring system of  claim 19 , wherein said flooring substrate comprises a concrete sub floor in which said tubing network is embedded.