Geothermal Heat Pump

An earth collector for the retrieval of geothermal
heat (heat from the earth the surface acts as a
hugh Solar collector) can be supplied in two
ways. Either as horizontal equipment embedded
at a depth of 1 to 1.5 mtrs below the ground
surface or as a vertical collector embedded in a
borehole(s) that can be up to 150mtr deep. The
pump used with these methods of heating is
known as a geothermal heat pump or an 'earth -
water' heat pump. In Ireland the ground
maintains a constant temperature between 11°C
and 13°C, several metres below the surface. For
every unit of electricity used to pump the heat,
3-4 units of heat are produced, leading to much
reduced fuel bills.

Horizontal Geothermal Collectors

Horizontal geothermal collectors are laid approximately 1-
1.5 mtrs below the surface. This is sufficient to protect the
piping from frost and to maximise on the the earths
geothermal heating. The earths heat is transferred through
a circulation circuit into the heat pump's evaporator by
means of a eat carrying fluid. This fluid cools inside the
heat pump and warms up again in the earth collector due
to the affects of geothermal heat.

Vertical Collectors

Vertical Geothermal Collectors work under the same
principle as the Horizontal Geothermal Collectors.
However, these collectors are embedded deep beneath the
earths surface in a singular or multiple boreholes that can
be up to 150mtrs in depth. This can be a major advantage
to a customer as they do not need to get a large area of
their site dug up if space
is a factor.

Payback

The initial capital costs of a ground source geothermal heat pump are usually higher than other conventional
heating systems. However the system is among the most
energy efficient and cost effective heating systems
available. Typically 3-4 units of heat are generated for
every unit of electricity used and the payback is about 8-10
years. This has been further improved due to the Greener
Homes Scheme . Once installed a heat pump requires very
little maintenance and a maintenance agreement can be
arranged with an Eirenew technician.