Ground Source Heat Pumps

A question about : Ground Source Heat Pumps

If anyone wants info on these, then please let me know, as have had one for over 5 years.

Best answers:

• Its always good to have input by people who have had real world experience of these systems. It will no doubt be of benefit if you could give details/costs and your views of your system.
  Thank in advance!
• Looked at these a couple of days ago. The site I looked at said they would not be very/as effective in an older property (draughty with poor insulation) and better suited to a modern home that meets current standards for draughtproofing and insulation.
• Okay, I live in Italy, in a mid 18th Century stone house at 450 mtrs altitude, close to a mountain range. Roof is insulated, double glazing and underloor heating (No wall insulation). Floor area heated 120 sq mtrs @ 19C 24/7. Hot water 48C 24/7 with regular boost to clear bacteria risk.
  GSHP: IVT Greenline HT+, 11Kw output inclusive of DHW cylinder. Cost installed here circa Euro 14K plus excavations for ground loops. You would probably be looking at lower cost in the UK.
  Electricity here is more expensive, so if someone can give me the cost per unit in the UK, I can give an idea of the rough cost based on pump running hours.
  I have 5 other people install the same system and all are really pleased, as no maintenance ( apart from clean 2 filters, ( which takes about 15-30 mins ).
  Ask away if you need more info
• Heat pump running hours for Nov - Dec: 198 (8/11-6/12)
  Dec - Jan: 321 (6/12-03/01)
  Multiply the figures above by 2.1 ( the kw the pump uses ) then by your unit kw cost for electricity, to give an estimate of the running cost.
  We have not had as much snow as yourselves, but have still gone to -10 at night
• My opinion is that it is the best form of heating, but then I am biased having spent the last 5 years with one. Underfloor heating is ideal for them, as you use low heat curves (usually max 35-38C).
  As regard to cost, I would suggest that you try to get a quote from one of the specialist UK suppliers, as we only deal with Italy, where costs are much higher than UK.
  If you let me know the approximate floor area of the house and insulation level, then I may be able to give you an idea of the pump size to look for.
  Remember you need a good size ground area if you go for the normal ground loops, otherwise there are compact collectors which only require about 40sq mtrs area. Boreholes are the most expensive.
  Try this company for a quote: iceenergy. I cannot post the link as a new user, but a google search will bring them up
• There is no real difference. Winter temps where we are in central Italy close to the Sibillini mountains get low in the winter, albeit not as bad as in the UK this year. The pump we have is designed to work down to -35C. Last year in Jan-Feb (our coldest months I was getting -1 to -2C feeding back into the ground loop ). House temp still stayed at its set temp of 19C and if I remember correctly, the 3Kw immersion only kicked in for about 2 hours overall when we had a really cold spike overnight. ( It will not switch on unless the pump compressor has had to work for over an hour ). In fact over 5 years, the immersion has only run for 24 hours in total, which is mainly to sanitise the DHW against bacteria.
• https://www.energysavingtrust.org.uk/...rce-heat-pumps
• Thanks Scotsman. I have read with interest the EST report and it does throw up a lot of questions. We are more tightly monitored here for grants etc. To get a tax reduction, you are required to state that the heat pump will give over 20% savings at least over a conventional system. With that you can recover up to 55% of all costs involved with the installation, even if this means having double glazing installed. All houses have to have a energy certificate to state the heating requirement ( thermal performance ).
  Energy costs here are very high and based on consumption, low to 1440Kw p.a, then to 2400, next to 4400Kw and then over that. We run from 11 cents Kw to 24 plus tax @ 10%. The house here uses in total circa 10k per year, although the pump only uses 1/3 of that consumption.
  I have one client who was using Euro 6000 in gpl per year, but this is eliminated and the GSHP is costing him between 1500-2000 Euro.
• Welda.
  There is no major difference in the ground temperature at 1.5 mtrs depth whether you live in the north of England or the north of Italy. We have no volcanos in this area, but do get seismic activity where the walls actually wobble like jelly, but something you get used to after the first couple of times.
  Please check actual facts, as we do not all live on volcanos here.
• Geotherm keep posting it is interesting.
  Do ground source heating systems produce much noise ?
  If I was going for it I would have to try the borehole method. I just think it would be far too expensive.
• Ok Welda. I was just referring to European areas. There are of course variations e.g. Lanzarote where the volcanic activity heats the ground in certain areas. We just have to take an average and work from that, unless there is more specific area data.
• Globalds. Think of the noise a refrigerator makes and that is close to a heat pump. I would try to go for a compact collector system against a borehole.
• There is a major factor to consider with gshp's....
  They are ok at first, as the surrounding temp is more stable in the borehole or ground loop than an ashp.
  However, over a period of years, the temp around the borehole / loop gradually declines and the environment is unable to replace the latent heat at the same rate as it's extracted. This means that the efficiency of the system will gradually decline. This can and DOES happen, but it can be several years before it's noticed.
• Spot on Chippy, system basically sucks out more heat energy that can be replaced by normal solar activity. Bore hole and surrounding area is froze!!