Ground Source Heat Pumps

dnichcole

poohbear59 wrote: »

Hello, Can I join in your discussion please? To set the scene.....We had our IVT C6 commissioned last week. We have a 95m bore hole. The house is empty at present so we have set the thermostat to 10oC indoor and it is using about 10kw per day. Although the building is extremely well insulated we still have the old barn door on the front so have huge gaps top and bottom and so are not running efficiently yet.

The property will be run as a self catering holiday cottage but I am not sure how well we will be able to manage the hot water for the cottage. It has 3 showers and a bath. We are going to set the system up and then lock the door to the GSHP cupboard so the occupants can't change the settings. Do you think providing constant hot water will be a problem for the cottage? We will be next door so can change settings quite quickly but I would like it to be self managing as much as possible.

YOu dont have to provide constant hot water, you have a timeclock in the IVT allowing you, for example, to turn DHW off at midnight and on again at 8am. Its possible to do similar for the heating function, independently of the DHW.
Also, the HW tank is very poorly insulated, the bottom of the HW tank has none, so you can reduce the water heating cost with a bit of thin superquilt cut into patches and fixed into place with duct tape.

If you are using 10 kWh a day in the last week, when mine has only been using 5-7 a day in the same conditions, it shows you really need to draft proof that barn door. It seems possible that the heat losses through ventilation will be catastrophically expensive during the winter.

lovesgshp

Some suggestions poohbear69.
If you have left the DHW on the original installation setting, reduce it to minimum, or even off until you have guests. Change to max temp and peak hot water the day before the clients arrive. Set the DHW timer to switch off at say 10pm to 7am.
Recharge times on DHW are quite rapid,as the system prioritises that area. I must admit, that I would have suggested a 300ltr/500 ltr tank with a E series pump, if you were having high occupancy.
Because of the DHW heat delta, plus peak heat, you should have no risk of bacterial infection.
Check the room sensor influence and set about 7. You could also set the summer disconnect temperature lower to reduce the running hours

lovesgshp

Cardew wrote: »

Eat your heart out Geotherm - this trumps your systems!

http://www.bbc.co.uk/news/uk-12549886

Sorry Cardew, seems like the deep drilling in the UK is starting to cause more problems. Soon it will be as bad there with tremors as here!!!

http://www.guardian.co.uk/uk/2011/jun/01/blackpool-earthquake-tremors-gas-drilling

lovesgshp

Any feedback on GSHP running costs in the UK? As temps are starting to get low here (10-12C @ 9.00am ), we are running at around 3 hrs per day, so circa 7kwh.

dnichcole

Hi, if you are using an average of 7 kWh/day you are doing well (assuming that it is doing the heating and the hot water. Mine is also averaging 6-7 per day in the last couple of weeks. Daily hours averaging 2.5. It also depends surely, on the heating demand i.e the amount of hot water you are drawing and the heat loss of the house.

nosha123

Hi Guys. Our GSHP has been averaging about 2.6hrs use per day... not sure on the kwh but our electricity meter for whole house is about 38kwh per day... what portion of that is the GSHP I dont know but we do have quite a big house. Have to say.. I love my GSHP!!!!!

dnichcole

If you fit a Landis Gyr or a Elster meter onto the GSHP cable you can know exactly how much it is using. Its a quick job, assuming you are on single-phase electricity, and such meters cost about £35. Unfortunately the same meter for 3-phase is about £90. It is a real help having a separate meter on the GSHP, enabling you to understand its performance, and to notice 'blips' eg when additional heat cuts in, etc. I take a daily reading from mine, comparing it to the House meter performance and to weather conditions.

lovesgshp

dnichcole wrote: »

Hi, if you are using an average of 7 kWh/day you are doing well (assuming that it is doing the heating and the hot water. Mine is also averaging 6-7 per day in the last couple of weeks. Daily hours averaging 2.5. It also depends surely, on the heating demand i.e the amount of hot water you are drawing and the heat loss of the house.

Hi
We do use quite a lot of hot water daily, but the timer switches it off from 20.30 until 07.30.
House heat loss is quite high, as 250 years old and stone build, with DG and roof insulation only (no loft). Plus the doors are open all day for the dogs to go in and out.
In the summer the pump was only running between 3 - 5 hrs a week for DHW only.

lovesgshp

nosha123 wrote: »

Hi Guys. Our GSHP has been averaging about 2.6hrs use per day... not sure on the kwh but our electricity meter for whole house is about 38kwh per day... what portion of that is the GSHP I dont know but we do have quite a big house. Have to say.. I love my GSHP!!!!!

As a rough guide, just multiply the running hours x input kw, for UF or rad temps. You should not be that far out.

dnichcole

If anybody is using a Ground Source Heat pump , is there a sort of club or association of GSHP users? For a year and a half, I have been using a solar panel as a sort of turbocharger to the GSHP - gives it a terrific boost when there is a nice day (and stores heat underground all through the summer) - reduced the GSHP consumption by a significant percentage. I'd like to tell others how to do this.