In a newly adopted position paper, the National Ground Water Association (NGWA) states that the loop tube is an integral part of the loop well in a geothermal heat pump system.
A loop tube is the heat exchanger conduit of a geothermal heat pump system
through which the heat exchange fluid is circulated and thermal energy transfer
takes place. The loop tube is emplaced to the bottom of the vertical borehole
and grouted from the bottom of the vertical borehole to the Earth’s surface at
the drill site.
“The National Ground Water Association believes the grout and the loop tube are
integral parts of the loop well, and that qualified individuals, such as a certified vertical closed loop
driller, should be authorized to construct
a loop well,” says NGWA in its position paper titled, “Construction of
Vertical Loop Wells for Geothermal Heat Pump Systems.”
NGWA’s position paper states that construction of a geothermal heat pump loop
well includes, in continuous order, drilling of the vertical borehole into the
Earth, placement of the loop tube to the bottom of the vertical borehole with
the grout tremie, and grouting of the vertical borehole from the bottom of the
vertical borehole to the Earth’s surface.
When these steps are completed, the vertical borehole may now be considered a
loop well. Loop emplacement and grouting should be performed in a timely manner
to guarantee successful loop tube placement, grout installation and
Loop Tubes “Integral” to Geothermal System
May 14, 2010