Abstract: A subterranean ground heat exchange system, a method of installation, and a grout composition therefor. The grout composition is a pumpable slurry formed of from about 70 to about 85 parts by weight natural flake graphite and from about 30 to about 15 parts by weight bentonite. The solids content of the pumpable grout slurry is preferably at least 35% by weight and is more preferably at least 40% by weight. The ground exchange apparatus preferably utilizes an improved supply and return header comprised of supply and return ports which are provided through the vertically extending outer wall of a header housing. The header also includes an interior supply conduit which extends from the supply port into the interior of the header housing and includes a bend positioned in the interior of the housing for directing the heat transfer fluid downwardly.

Abstract: A subterranean ground heat exchange system, a method of installation, and a grout composition therefor. The grout composition is a pumpable slurry formed of from about 70 to about 85 parts by weight natural flake graphite and from about 30 to about 15 parts by weight bentonite. The solids content of the pumpable grout slurry is preferably at least 35% by weight and is more preferably at least 40% by weight. The ground exchange apparatus preferably utilizes an improved supply and return header comprised of supply and return ports which are provided through the vertically extending outer wall of a header housing. The header also includes an interior supply conduit which extends from the supply port into the interior of the header housing and includes a bend positioned in the interior of the housing for directing the heat transfer fluid downwardly.

Abstract: A method, apparatus, conduit, and composition for low thermal resistance ground heat exchange which preferably comprise, include, and/or use one or more of: a thin-walled, highly conductive filament wound conduit/casing formed using a thermosetting plastic composition containing a thermal conductivity enhancer; a grout backfill preferably including a sufficient amount of graphite, coke, or similar additive to provide a thermal conductivity of 3 Btu/hr-ft-° F. and higher; and a drop tube delivery conduit within the casing, the drop tube having radial exterior ribs which extend into the fluid return annulus formed between the interior wall of the casing and the exterior of the drop tube.