On 02/02/2011 12:19, PeterL wrote:
Does anyone have any views or experience, please? Good or bad.


HI Peter
We have a ground-source heat-pump installation here (far south-west of
Ireland)
Total install costs were c. 12k euro - but there was a subsidy available
(c. 4k euro) at the time.

Our heat-pump lives outside in the timber-built studio - and draws heat
from 6 x 100m loops, set in three 50m trenches, partly under the
polytunnel. The ground-work is a significant part of the install costs -
in our cease we had to do some earth-moving anyway - so buried the loops
at the same time.

Our pump is designed to replace a conventional boiler (original install
was an oil-fired unit) - and circulates water at about 55 - 60c to
radiators. If designing from scratch, you'd want larger rads or
underfloor pipework.

Had to replace the hot-water cylinder with one that had a larger, longer
coil, as otherwise the heat-pump got upset at the reduced heat-loss..

We like to have 2 baths one-after-the-other of an evening - and find
that there's a tiny amount of mains immersion heater needed just to top
off the tank and achieve this. If the DHW tank was a little larger then
this wouldn't be a problem.

Can't comment on actual cost of operation - but I believe it to be
cheaper than oil, more convenient and less smelly! g

Servicing costs - so far (fingers crossed) - zero in 3 years.
Electric supply needs to be sized carefully - unit takes 15A when
running - but has a fairly high inrush on starting (32A slow-trip MCB
required).

Hope this helps.
Adrian