Ground Source Heat Pumps

Baysurfer

I have a quote for a GSHP installation but no costing for the ground works? could someone give me a rough idea of the likely cost of this part of the project please. (either DIY or contractor)

Requires 3 x 50m trenches 1m x 1m deep for slinky coils with 100mm sand bed and 100mm sand cover then back fill

Also a comparable cost of boreholes would be useful?

Thanks

lovesgshp

Baysurfer wrote: »

I have a quote for a GSHP installation but no costing for the ground works? could someone give me a rough idea of the likely cost of this part of the project please. (either DIY or contractor)

Requires 3 x 50m trenches 1m x 1m deep for slinky coils with 100mm sand bed and 100mm sand cover then back fill

Also a comparable cost of boreholes would be useful?

Thanks

Those trenches should not take more than 2 days, to excavate and back fill. I do not know what the costs in the UK are, but, here they charge about Euro 60 p.h for a jcb digger, or 45 ph for a bobcat size, including the operator. Sand cost should not be too high.
Boreholes, you could probably at least quadruple the cost, as that is the most expensive solution.
HTH

poohbear59

We have a borehole for ours. Two years ago it cost us £4400 for a 95m deep borehole. We could have gone with a cheaper company but they had extra charges if the drill bit was damaged or it needed extra lubrication. We saved money as the drilling hit problems for which we would have incurred costs.

The only reason we didn't go for trenches was that after we had a septic tank in the garden there wasn't enough space left because we have a lot of rock here.

Silent_Dancer

Get the installer to quote for the groundworks. If there any issues with them you'll have a single point of contact to resolve problems.

slimfandango

paceinternet wrote: »

nosh, I think you have probabaly got an ok system that is providing the heating required. See what geotherm says as well.

For anyone else coming back to read this, it goes some way to confirm what I said a while ago, and really "Ice" should have been more open about how it would run and the costs. They should have given you the choice of a bigger unit to compare the capital and running cost with the one you have. You probably would still have chosen the solution you have because:
1. We have had 2 quite cold months while it has been running so far and it has cost you about £200 extra. If the heat pump could have provided that heat, it would have cost about £70 for the compressor, so you have paid £130 extra.
2. Maybe we will get another 30 days in a 12 month period where additional heat is needed, so costing you another £70 extra.
3. Total extra spend is about £200 a year.

A 16kw heat pump would cost an extra ££?? to save £200 / year. A 14kw model might have been a good compromise, but if your "additional heating" running hours are not increasing on days when it is, say, above 0degc, then you should be ok.
Have you said where you are in the country and any idea how many days are below zero (assuming zero is somewhere near where additional heat is required)?

Add higher grants and RHI for having a larger, greater % of requirement system = $$$$?

Sarah715

I was looking at getting a getting a heat pump and at the renewable heat incentive that the government provides.
I came across this calculator which helps to give you an idea of what you might get. It is quite broad but I think it will be quite useful
http://www.reinagroup.co.uk/mcs-heat-pump-design-and-installation/rhi-calculator-tool/

fluffymuffy

Sarah715 wrote: »

I was looking at getting a getting a heat pump and at the renewable heat incentive that the government provides.
I came across this calculator which helps to give you an idea of what you might get. It is quite broad but I think it will be quite useful
http://www.reinagroup.co.uk/mcs-heat-pump-design-and-installation/rhi-calculator-tool/

Crazy Prices !

I just put my data in - house age/size etc and it told me ....
- a ground source heat pump installation would cost £72,109.51

- an Air Source heat pump would cost £18,776.16

I've just installed my own for £580. OK it's only 5.2kw. Perhaps the one quoted has a higher output. I could install 4 for £2K. That would be warm enough to compare.

lovesgshp

fluffymuffy wrote: »

Crazy Prices !

I just put my data in - house age/size etc and it told me ....
- a ground source heat pump installation would cost £72,109.51

- an Air Source heat pump would cost £18,776.16

I've just installed my own for £580. OK it's only 5.2kw. Perhaps the one quoted has a higher output. I could install 4 for £2K. That would be warm enough to compare.

No idea what data you put in, but have just put in for here in the calculator for a GSHP on a pre 1900's house with Double glazing, 120 m2 and the figure came out at circa 17K. That is probably close to the normal costing.
Your £580 is probably a cheap Chinese import, as I presume it is a ASHP.
Putting in the same figures for a ASHP arrived at under 8K
As another edit, your 5.2 kw output is probably for a sub 100 m2 property, with high insulation, as circa 100m2 would require between a 7 or 9 kw output unit.

lostinrates

Our real life quotes for ASHPs come at at circa 20k for 2 16 kw daiken units. ( obviously more than many younger houses would need)

Cardew

lostinrates wrote: »

Our real life quotes for ASHPs come at at circa 20k for 2 16 kw daiken units. ( obviously more than many younger houses would need)

I really can't get my head around these figures.


How much are your heating and hot water bills?(not 'general' electricity consumption)


The average is less than £1,000.


Oil is around 6p to 7p/kWh depending on boiler efficiency.


The average system COP for ASHPs was 2.45 on the recent EST trial - and that was with all the manufacturers supervising the modifications to the installations. The majority had a COP of 2.0 or 2.2p.


So assuming you got the average COP of 2.45 that prices a kWh of heat at approx. 4.5p/kWh. With an old house you might well not get 2.45.


Even with our rock bottom interest rates, at 3%pa £20,000 invested in a long term account will still attract £600pa in interest.


It just cannot make economic sense to pay £20,000 for an ASHP.