Ground Water Heat Pump Installations

Cushing and Sons has completed a number of Ground Water Heat Pump (GWHP) installations throughout New England over the past decade since the popularity and dependability has been proved for this emerging technology.

Groundwater Source Heat Pumps, also known as geothermal heat, is a newer heating system technology that uses water as the medium for heat transfer. There are two types of Ground Water Heat Pump installations:

• Closed loop systems use the vertical borehole lineage for thermal transfer. Commonly, 1.25" specially manufactured black poly pipe is installed in the borehole as a loop, (called a U tube) and the annular space between the well and the poly pipe is grouted with thermal transfer clay material. Some closed loop systems utilize copper refridgerant piping and use freon as the product that is circulated versus water in the poly piping. Closed loops are often times touted by some experts as the most economical to operate, most stable and maintenance free, often utilizing small fractional horsepower circulator pumps. For most residential needs, two to three 300 ft. boreholes are utilized. Commercial installations may have dozens of boreholes.
• Open systems have two common types, the "pump and dump" and the standing column. Pump and dump takes the water out of the well, go through the heat pump and dumps the water into a dry well, drain field, or similar structure to allow the water to go through the hydrologic cycle and return the water to the ground. Standing column employs a smaller casing in the well forcing the water to go from the pump down the annular space of the borehole and liner where by the water is forced to travel the length of the column for thermal transfer. Generally speaking, "pump and dump" works fine with wells that are shallow and have adequate yields. Standing column works well and is the most economical to operate with deeper wells and lesser well yields. Cushing and Sons has installed pump systems in both types, with conventional systems or the newer variable speed type pumping equipment.

Whichever way the system is designed, we size the system working with your applications engineer or heat pump dealer. Our function is to drill the boreholes as specified and install the tubing or pumping equipment to go into the heat unit in the basement. We have the proven skills to install these for years of trouble free service.