OPEN-LOOP SYSTEMS work best in locations where there is
a well or surface body of water readily available. Because of
these requirements, open-loop systems are less commonly
found than their closed-loop counterparts.
CLOSED-LOOP SYSTEMS can minimize the disturbance to
existing landscaping and be used in areas where the soil is
too shallow for trenching. Vertical orientations are often used
because they require less land area for installation.
Based on your location and building’s property, you will need a specific type of geothermal heat pump
system. They are classified into three main
Closed-loop systems typically circulate
an antifreeze solution through a closed
loop often made of plastic tubing that is
buried underground or submerged in water.
The system exchanges heat between the
heat pump’s refrigerant and the antifreeze
solution in the closed loop. Loops can be
oriented horizontally, vertically, or in a pond
or lake, but vertical is most commonly used
in commercial buildings, schools and other
larger facilities because it can be implemented in locations with land area restraints.
Open-loop systems use well or surface body water as the conduit for heat
TYPES OF GEOTHERMAL HEAT PUMPS
exchange to circulate through
the system. Once the water is
cycled through the system, the
water returns to the ground
through the well, a recharge well
or surface discharge. Open-loop
systems only work where there
is a ready supply of clean water
and the system meets groundwater discharge codes and regulations.
Hybrid systems will use
multiple geothermal resources
or a geothermal resource with
outdoor air through the use of
a cooling tower, for example.
These systems are most effective when a building needs more
cooling power than heating.
U. S. DEPARTMEN T OF ENERGY