Ground Source Heat Pumps

beardymarrow

beardymarrow said:

ccbrowning said:

shinytop said:

I don't think the EPC calculations take account of the COP of the A/GSHP. It just assumes it's electric heating which gets marked down because it's expensive.  Daft I know.

The numbers don't look unreasonable for a new build.  Whats the area/size of the house?

208 m2 over two floors. 

Does seem like the whole EPC system is in need of updates, tho. Perhaps you’re right about how it is interpreting electric. Sure, it’s electric, but using electricity to heat water, etc. 

Ours is a little bit bigger than that (230m2} and we only have UFH in half the ground floor. We're consuming 15000kwh per year in total (not just for heating and hot water) so I'd say the 3000kwh would be optimistic, but the 12000kwh from the epc just for heating and hot water does seem pessimistic. If you budget for 12000 you'll hopefully be pleasantly surprised. Time will tell as you say. 

For what it's worth, just found our EPC. The house is actually 300m2 and the EPC said 22000kwh for heating and hot water, but we're using 15000kwh in total. 

ccbrowning

Reed_Richards said:

ccbrowning said:

I spend more currently for gas and electricity in my current home, which was built in 2014 and has gas-heated UFH just on the ground floor. I’ll report once we’re actually in the new place and get some real numbers. 

So how do the EPC figures for your current place compare?

EPC 81, new one is 90. Estimates current would be 89 with solar PV, which the new GSHP house has and is only 90. 

Reed_Richards

I intended to ask how the estimates for heating and hot water compare.  If you can achieve a SCoP of 4 with your GSHP and UFH then the running cost should be on a par with gas.  I think you're certainly in with a chance of achieving that.   So if the new house requires less energy than your old one then hopefully your energy costs will be less.      

ccbrowning

Reed_Richards said:

I intended to ask how the estimates for heating and hot water compare.  If you can achieve a SCoP of 4 with your GSHP and UFH then the running cost should be on a par with gas.  I think you're certainly in with a chance of achieving that.   So if the new house requires less energy than your old one then hopefully your energy costs will be less.      

Understood!

• New Home Estimate: 11804 kwH
• Current Home Estimate: 8966 KwH
• Current Home Reality: 11742 KwH (Nov 2020 - Nov 2021)

New home is 208 m2 vs 130 m2, but maybe even better insulation, is 2 floors instead of 3, and has UFH on both floors instead of just ground. Will be interesting to see.

Reed_Richards

Something here about Heat Pumps and EPCs (quite a lot, actually): 

https://www.yorkshireenergysystems.co.uk/epcandheatpumps/

beekeeper2003

Just wondered if someone may be able to point me in the right direction. I have 2 No IVT Greenline HT Plus C heat pumps (with the internal hot water tanks). One of them is losing pressure over time despite re-pressurising it off the cold water system - I am not aware of any leaks and wonder if it might be an expansion vessel that is failing or that needs re-pressurising. There are two of these for each pump, a white one over the top of the pump (difficult access) and a red one on the wall (easier access) . Just wondered if anyone might know which I should turn my attention to first - any tips or guides also gratefully received.

Reed_Richards

With a failing expansion vessel what you would see is that the pressure increases when the fluid get hotter.  

beekeeper2003

Reed_Richards said:

With a failing expansion vessel what you would see is that the pressure increases when the fluid get hotter.  

Thank you - I shall try and monitor that and then turn my attention to which vessel does what.

Strummer22

Hi, just wondering if anyone can advise the best electricity supplier and tariff for running a GSHP? We are having a 22kW unit installed within the next month so the majority of our electricity use will due to the GSHP. There is no gas supply.

Thanks in advance.

beardymarrow

Strummer22 said:

Hi, just wondering if anyone can advise the best electricity supplier and tariff for running a GSHP? We are having a 22kW unit installed within the next month so the majority of our electricity use will due to the GSHP. There is no gas supply.

Thanks in advance.

Hi,
It makes no difference that it's GSHP (other than probably Economy-7 won't give you any benefit), so go with whoever is cheapest for your total consumption.
https://www.moneysavingexpert.com/utilities/cheap-gas-and-electricity/
Beardy