Ground-source heating systems
generally require three main
components: the heat exchanger
(ground loop), a heat pump
(condensing unit) and a
distribution system such as air
ducts or in-floor tubing (Figure 2).
The heat exchanger or loop is
simply a length of tubing placed
underground and used to transfer
the heat from the ground to the
heat pump. The heat pump
concentrates the heat using a
condensing unit. In the winter,
that heat is transferred to the
distribution system and released
through the building’s air ducting
systems or in-floor hot water
(hydronic) heating system. The
process can be reversed for cooling.
A water-antifreeze mixture is used
as the transfer medium between the
heat source (the ground) and heat
pump. The heat pump concentrates
the heat and disperses it into the
home. Household air is never in
direct contact with the heat source
(air, soil or water).