30 May 2005

GROUND SOURCE HEAT PUMP WITH A NEW COMPACT COLLECTOR

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A fundamental point, strongly effecting the development of a heat pump market, is economy.
Installation of a Ground source heat pump (GSHP) is normally more expensive than a gas/oil boiler. In
this paper we present a way to reduce the cost of installation.
The total cost for a Swedish heat pump installation is USD 14000 to 20000. The cost is divided
into three parts:
• Heat source, normally vertical or horizontal ground loops, 35-40%
• Heat pump, 40 %
• Installation, 20-25%
A short pay-back time (total investment divided by first year savings) is one reason why the
Swedish market for Ground source heat pumps was near 39000 units year 2004 (SEV/SVEP market
statistics 2004). The normal pay-back time in a Swedish installation is 5-7 years. For the rest of
Europe the pay-back time is longer due to higher investment and smaller savings. The high investment
is mainly due to higher cost for the heat source. Horizontal collectors are not suitable because of small
garden areas and vertical collectors, boreholes, are sometimes very expensive due to variable rock
quality. The vertical collector only, can cost up to USD 10000-14000 in certain areas. This high level
of investment is a large barrier and therefore the number of installed Ground source heat pumps is
comparably small in central Europe.
Our idea is to increase the heat pump market by reducing the main barrier, cost of installation,
and specially reduce the cost of the heat source.
To do this, we have developed a new highly efficient compact collector. The collector requires only a
small garden area and it can be installed in less than a day. The compact collector is always combined
with heat recovery from exhaust air. By using this combination the compact collector is recharged
continuously. The system is also securing a good indoor climate, thanks to the continuous ventilation.