Your browser isn't supported
It looks like you're using an old web browser. To get the most out of the site and to ensure guides display correctly, we suggest upgrading your browser now. Download the latest:

Welcome to the MSE Forums

We're home to a fantastic community of MoneySavers but anyone can post. Please exercise caution & report spam, illegal, offensive or libellous posts/messages: click "report" or email forumteam@.

Search
  • FIRST POST
    • lovesgshp
    • By lovesgshp 6th Jan 11, 7:18 PM
    • 1,251Posts
    • 702Thanks
    lovesgshp
    Ground Source Heat Pumps
    • #1
    • 6th Jan 11, 7:18 PM
    Ground Source Heat Pumps 6th Jan 11 at 7:18 PM
    If anyone wants info on these, then please let me know, as have had one for over 5 years.
Page 3
    • lovesgshp
    • By lovesgshp 24th Jan 11, 8:48 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    This MSc Thesis paper may go some way to explaining loss of thermal recharge, although I reckon you will know of this possibility.

    Page 37 on pdf doc.

    http://www.esru.strath.ac.uk/Documents/MSc_2007/Le_Feuvre.pdf



    Please note copyright, link added for perusal/illustrative purposes only.
    Originally posted by welda
    See that he is mainly talking about borehole heat loss. Here is a paper our guys wrote for a Geothermal conference related to solar recharging on compact ground collectors.
    http://www.geotherm.it/Ricerca_scientifica_geotermia_files/P.4.45_maritan.pdf
    • welda
    • By welda 25th Jan 11, 6:58 PM
    • 580 Posts
    • 270 Thanks
    welda
    Hi,

    Have to say I had a quick look at study paper you provided, the point trying to be put over is the fact GSHP through time can deplete thermal energy at a rate where mother nature cannot replace.

    I suppose common sense will say compact systems at approx 1.5 metre below ground will stand a better chance to replenish due to being closer to thermal charge source? One main point that appears to have a MAJOR impact on these systems, is overall competence when a property is being surveyed for what it requires.

    Test rigs arrived today, will give me a better understanding of equipment used, then better grasp of the over all technology...........hopefully

    Last edited by welda; 25-01-2011 at 7:01 PM.
    • lovesgshp
    • By lovesgshp 25th Jan 11, 9:19 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Hi,

    Have to say I had a quick look at study paper you provided, the point trying to be put over is the fact GSHP through time can deplete thermal energy at a rate where mother nature cannot replace.

    I suppose common sense will say compact systems at approx 1.5 metre below ground will stand a better chance to replenish due to being closer to thermal charge source? One main point that appears to have a MAJOR impact on these systems, is overall competence when a property is being surveyed for what it requires.

    Test rigs arrived today, will give me a better understanding of equipment used, then better grasp of the over all technology...........hopefully

    Originally posted by welda
    When I posted originally, arguing about heat loss, I was referring to a horizontal system, as that is virtually unchanged. I put the above pdf link as additional from our research and in consideration of the earlier data link, as we know there has to be a recharge, due to the system heat replenishment constraints.
    • lovesgshp
    • By lovesgshp 26th Jan 11, 5:34 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Have been running some actual scenario tests over the last week and will post the results at the weekend, as have to let the unit stabilise from the last changes ( min 24hrs ).
    1) Heat pump working in normal mode for DHW/Heating
    2) Internal house log burner working ( no connection to either DHW/Heating ) with pump as in 1
    3) Increasing internal temperature by 1C to 20C. (pump usage only ).
    Average temps at the time (9.30 a.m. circa 1.5C) with 4 inches of snow on the ground. Internal temp sensor @ 70% influence over external unit. Underloor heating, no buffer tank.
    • lovesgshp
    • By lovesgshp 28th Jan 11, 5:25 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Results from the above running tests:
    1) With the pump running normally @19C for inhouse temp: Ground loop temp in 6.0C out 3.5 (delta 2.5C ) Operating hours 10 - 11 per day x 2.1Kw base = 21/23Kw + approx 2Kw for circulating pumps.
    2) With the internal fire and no change in the above settings: House temp increased to 21C and heatpump running hours reduced to 8. Ground loop temperatures rose by over 2C input, showing the recharge was working even with a 2-3 hr reduction in operating times. Cost offset has to be considered here, as we pay circa Euro 12 per 100Kg of wood, so over the few days we probably burnt 30 KG min.
    3) Increasing the temp to20C showed a significant change in running times. The first day after the increase, the pump ran for 17hrs, 2nd day 14hrs and has now stabilised @ circa 12 hrs. Ground loop inflow has reduced to 3.5C in/ 1.1 out. Heating delta on the heat transfer system has stayed at a 6.5C in all the above situations.
    • nosha123
    • By nosha123 31st Jan 11, 5:55 PM
    • 39 Posts
    • 8 Thanks
    nosha123
    Geotherm - would love your help please!
    Wow your timing is somewhat perfect!

    We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
    Will give as much spec here as I can
    Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
    House is chalet bungalow with basement. All UFH and super insulated.
    Floor area being heated is somewhere in region of 350m2.
    We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
    Been living in house for 2 months now. First bill based on actual reading is £590.
    We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
    Am hoping something is set up wrong and future bills wont be £300 per month!
    All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
    Our Elec supplier is E-On. Tariff is
    Normal units up to 900 kWhs per year
    18.858 pence
    Normal units
    8.589 pence per kWh

    Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????

    The GSHP engineer said the Pump was drawing the same power as 2 kettles....WTF???
    • Cardew
    • By Cardew 31st Jan 11, 7:20 PM
    • 26,733 Posts
    • 12,927 Thanks
    Cardew
    Wow your timing is somewhat perfect!

    We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
    Will give as much spec here as I can
    Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
    House is chalet bungalow with basement. All UFH and super insulated.
    Floor area being heated is somewhere in region of 350m2.
    We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
    Been living in house for 2 months now. First bill based on actual reading is £590.
    We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
    Am hoping something is set up wrong and future bills wont be £300 per month!
    All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
    Our Elec supplier is E-On. Tariff is
    Normal units up to 900 kWhs per year
    18.858 pence
    Normal units
    8.589 pence per kWh

    Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????

    The GSHP engineer said the Pump was drawing the same power as 2 kettles....WTF???
    Originally posted by nosha123
    With that EON tariff you have used about 7,000kWh in 2 months.

    Let us assume that you have used 1,000kWh in non-heating applications, that is approx 6,000kWh in 2 months for heating and hot water.

    If your system has achieved an overall COP of 2.0 that is 12,000kWh

    The temperature of the water in the UFH and particularly the DHW has a large influence on the efficiency and how often the immersion heater kicks in.

    It has been an extremely cold 2 months and yours is a large house. If the engineer said it was drawing the same power as 2 kettles that is 6kW.

    Personally I would have been surprised if a 6kW system(if that is what he means) would cope in such a large house.

    Anyway Geotherm has a lot more knowledge on GSHPs and no doubt he will comment.

    P.S.
    If it is any consolation whilst induction hobs can draw lots of power, they are far more efficient than 'normal' radiant hobs and use less power.
    • lovesgshp
    • By lovesgshp 1st Feb 11, 8:57 AM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Wow your timing is somewhat perfect!

    We have just had our first bill after fitting our GSHP two months ago and i am somewhat shocked at how high it is!
    Will give as much spec here as I can
    Fitted a Ground Source Heat Pump Greenline HT + E11 (Single Phase, Soft Start) (supplier: Ice Energy)
    House is chalet bungalow with basement. All UFH and super insulated.
    Floor area being heated is somewhere in region of 350m2.
    We have a ground loop in the garden and a friend fitted same system but their bills are significantly less!
    Been living in house for 2 months now. First bill based on actual reading is £590.
    We are 2 adults (though had guests over xmas) and have 2 single ovens, an induction hob (which apparently draws a lot of power!) TVs, washing machine (not been using tumble dryer!).
    Am hoping something is set up wrong and future bills wont be £300 per month!
    All room stats are set to about 20 or 21 degrees. SOme of the UFH was accidentally set to ON permanently rather than coming on and off during course of day.
    Our Elec supplier is E-On. Tariff is
    Normal units up to 900 kWhs per year
    18.858 pence
    Normal units
    8.589 pence per kWh

    Hope this all makes sense! Why on earth are our bills so high? I know the house is big.. but really????

    The GSHP engineer said the Pump was drawing the same power as 2 kettles....WTF???
    Originally posted by nosha123
    Nosha123.

    Can you please take a number of readings for me from the 2nd customer screen (K2).
    I need all within menu 1
    All readings from menu 3 after pump has been running on heating cycle for approx 10 - 15mins
    Readings from menu 7
    Details of recent alarms from menu 11
    Thanks

    Have you 70% of the underfloor heating open?
    Last edited by lovesgshp; 01-02-2011 at 1:20 PM. Reason: underfloor heating question
    • nosha123
    • By nosha123 1st Feb 11, 9:40 AM
    • 39 Posts
    • 8 Thanks
    nosha123
    Thanks Chaps.. and thanks Geotherm.
    I will have to come back to you with the readings... give me a day or two to get this sorted (am not at home right now!!).

    Really appreciate your help on this too!!
    • lovesgshp
    • By lovesgshp 1st Feb 11, 2:13 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Also surprises me Cardew, that the engineer is saying that the unit is using the power of 2 kettles. At 0/35C, the power consumption is 2.2 kw on that model, rising to 3.0 with a 50C temp output, plus circulating pumps. The electric backup heater should not be cutting in under normal operating conditions and this is why I have asked for menu7 readings, as these show normal operation plus electrical immersion input.
    With the same model here, I only use around 10k Kw per year in total for the house and all appliances (3kw oven, washing machine, tumble dryer, dishwasher, 2 fridge/freezers etc ).
    I need to look at the running figures and temperature deltas to start with and then go from there with other settings.
  • paceinternet
    I think it is unlikely nosha123 is able to heat 350m2 in the weather conditions we have had in the last 2 months with the heat pump alone.
    A rough optimistic guide at 50w/m2 would suggest 17.5 kw is needed.

    2.2kw input: what is the output at 0/35C ?

    If it was a 6kw input (2 x 3kw kettles) and 18kw output then that would be more realistic.
    Last edited by paceinternet; 01-02-2011 at 2:31 PM.
    • lovesgshp
    • By lovesgshp 1st Feb 11, 2:48 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    I think it is unlikely nosha123 is able to heat 350m2 in the weather conditions we have had in the last 2 months with the heat pump alone.
    A rough optimistic guide at 50w/m2 would suggest 17.5 kw is needed.

    2.2kw input: what is the output at 0/35C ?

    If it was a 6kw input (2 x 3kw kettles) and 18kw output then that would be more realistic.
    Originally posted by paceinternet
    The output on that particular unit is 10.7Kw @35C. At 50C this decreases to 10.1 Kw. The company that installed it, ( who have been going for a number of years ) would have calculated the thermal requirements for the house, based on insulation and thermal loss so therefore the pump should be sized correctly.
    A 16.7 Kw output pump requires 3.7Kw input @ 35C and 4.9Kw @ 50C.
    I deal with these units on a daily basis, so I hope you can understand I have a lot of knowledge about them.
    • nosha123
    • By nosha123 1st Feb 11, 4:46 PM
    • 39 Posts
    • 8 Thanks
    nosha123
    well you chaps sound very knowledgeable (though I have NO bleedin' idea what you are talking about!!!) but I will endeavour to get those readings and advise as soon as I can!!!

    I'm guessing that its the GSHP thats the problem rather than the appliances in the house! As we just have the normal ovens x 2, hob x 1 fridges x 2 TV's etc...

    I'll be back as soon as I have some more detail!

    Thanks for helping me!
    • lovesgshp
    • By lovesgshp 1st Feb 11, 4:49 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    well you chaps sound very knowledgeable (though I have NO bleedin' idea what you are talking about!!!) but I will endeavour to get those readings and advise as soon as I can!!!

    I'm guessing that its the GSHP thats the problem rather than the appliances in the house! As we just have the normal ovens x 2, hob x 1 fridges x 2 TV's etc...

    I'll be back as soon as I have some more detail!

    Thanks for helping me!
    Originally posted by nosha123
    Don't worry Nosha, sure we will be able to work it all out in the end
  • paceinternet
    calculated the thermal requirements for the house
    Unfortunately, most of the posts in the forum about heat pump problems are because that requirement is not done correctly for the outdoor temperatures we have been experiencing in the UK. Too many installers either do not understand the reduced outputs, or choose not to explain how the system will operate in these situations together with the running costs.
    I also have some experience with heat pumps, but they are being criticised too often because of the lack of professionalism by the installer/specifier.
    • nosha123
    • By nosha123 1st Feb 11, 5:18 PM
    • 39 Posts
    • 8 Thanks
    nosha123
    I was always under the impression our supplier was very knowledgable - and have recommended them to other friends who are very happy with their system. Neighbours of ours have their loop in the river - and although their house is half the size of ours - their bills are just £300 per YEAR!!!
  • paceinternet
    Nosha123, you said "and a friend fitted same system but their bills are significantly less!".
    Is their property in the same location as yours, same 350m2, and some UFH been running "accidently on permanently", or same running hours, and same room temperature settings, and same electric tariff?

    It is much better to compare kwh usage with respect to running hours and room temps and m2. Then a better comparison can be made and you can ask the installer if that is what they would expect from their design.
    • lovesgshp
    • By lovesgshp 1st Feb 11, 5:38 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    I was always under the impression our supplier was very knowledgable - and have recommended them to other friends who are very happy with their system. Neighbours of ours have their loop in the river - and although their house is half the size of ours - their bills are just £300 per YEAR!!!
    Originally posted by nosha123
    Nosha
    Your supplier is one of the earliest companies in the UK for this technology, so I would concur that they know what they are talking about. I still think there is a solution, but as I say, the readings from your system will help very much to try and identify a problem.
    The E11+ has performance level to -35C to cope with Swedish winters, my initial thoughts are that a setting is wrong.
  • JDoddY
    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
    Originally posted by Geotherm
    It's nice to hear that you are so happy with your GSHP - however did you source it from Ice Energy as you have recommended?
    I have installed the 11Kw model in my house and I am presently in conversation with thier tech support group to explain why my electricity bill has gone through the roof. Since I started logging its performance at the beggining of December my electricity consumption is over £1000!

    I need to engage with someone who not only knows how this technology works but can examine my house and tell my if my system IS as I am beginning to suspect, grossly under-sized.
    If you can help I will be grateful -or if not potentially broke by September:-)
    • lovesgshp
    • By lovesgshp 1st Feb 11, 5:52 PM
    • 1,251 Posts
    • 702 Thanks
    lovesgshp
    Nosha123, you said "and a friend fitted same system but their bills are significantly less!".
    Is their property in the same location as yours, same 350m2, and some UFH been running "accidently on permanently", or same running hours, and same room temperature settings, and same electric tariff?

    It is much better to compare kwh usage with respect to running hours and room temps and m2. Then a better comparison can be made and you can ask the installer if that is what they would expect from their design.
    Originally posted by paceinternet
    I think, that we should wait until we get the readings and then go from there. It is no good just questioning without the basic information.
    I do agree with your comment regarding installers who do not know what they are talking about, but this is the norm with companies that jump on the bandwagon. Ice energy are a long established UK company. IVT is also one of the largest European suppliers of heat pumps.
Welcome to our new Forum!

Our aim is to save you money quickly and easily. We hope you like it!

Forum Team Contact us

Live Stats

150Posts Today

2,581Users online

Martin's Twitter