"Free" GSHP central heating

[PREES]

We are renovating a large 4 bed detached house for renting and we have been offered a free GSHP radiator based central heating system for free but they claim the RHI. The house has been internally lined so the insulation is good. Is this a good deal? Potentially we could install PV panels to generate the electricity but as we will be renting it out initially there seems little point (unless we sell the electricity to the tenants? )

 

[rogeriko]

Dont do it, you'll be sorry. GSHP's work with underfloor heating not radiators. Who is going to pay the enormous electric bills and live in a cold house. As a landlord you must provide a decent heating system in a rental property. The idea behind the RHI is to offset the electric bills otherwise no-one would do it. They will install the cheapest system available with the shortest ground loops possible and walk away with your money. Do it yourself with underfloor heating and keep the RHI yourself to pay back the cost of the system. About 6/7 years.

 

[f0ster]

yes! as has already been pointed out steer well clear of that one.

 

[Farmer_Joe]

Dont do it, you'll be sorry. GSHP's work with underfloor heating not radiators. Who is going to pay the enormous electric bills and live in a cold house. As a landlord you must provide a decent heating system in a rental property. The idea behind the RHI is to offset the electric bills otherwise no-one would do it. They will install the cheapest system available with the shortest ground loops possible and walk away with your money. Do it yourself with underfloor heating and keep the RHI yourself to pay back the cost of the system. About 6/7 years.

rubbish, ive got GSHP on all radiators and it brilliant, had it 10 years and it works very well, well insulated house running at a constant 20 degc.

Some people talk alot of sh!t around this, ive got one it works, just get the coil in wet clay with tiny blinding of sand if it stony its it clean clay just put them straight in!

cant comment on the scheme though i have no idea

 

[Steevo]

rubbish, ive got GSHP on all radiators and it brilliant, had it 10 years and it works very well, well insulated house running at a constant 20 degc.

Some people talk alot of sh!t around this, ive got one it works, just get the coil in wet clay with tiny blinding of sand if it stony its it clean clay just put them straight in!

cant comment on the scheme though i have no idea

How do you find the electric cost?

 

[Farmer_Joe]

How do you find the electric cost?

good combined heating and electric around 1400 a year large 4 bed house plus all farm, its gone up since we got tumble dryer but ive got 4 kids, this includes a fair amount of welding and fabrication too.

You need well insulated house, plus pipes laid in correct conditions, it relies on conducting heat from ground hence wet clay, ive heard of people laying them in gravel so they just dont work.

And remember its 20 deg c 24-7 365 in house its on all the time.

 

[Mur Huwcun]

That’s very good, we’re on £12-1400 per year really for 4 bed house with underfloor and rads upstairs. It sounds excessive maybe but most I know that live in two or three bed houses in town etc are on £90 a month on duel fuel.

How’s your brine temp running this year? Ours at present is better than what it was this time last year but we’ve not really had any cold weather to really test it but enough wind and we’re an exposed house. Easterly wind hammer this house and half the house will feel significantly colder when wind is against the East gable end.

good combined heating and electric around 1400 a year large 4 bed house plus all farm, its gone up since we got tumble dryer but ive got 4 kids, this includes a fair amount of welding and fabrication too.

You need well insulated house, plus pipes laid in correct conditions, it relies on conducting heat from ground hence wet clay, ive heard of people laying them in gravel so they just dont work.

And remember its 20 deg c 24-7 365 in house its on all the time.

 

[Farmer_Joe]

we are the same, prevailing east wind does hit us but as you say its been mild so far, not checked brine temps in ages, its usually around 8-9 recovery i.e goes out at 0-1 comes in at 9-10.

it has improved the longer its been in, im sure this is to do with the ground settling around the pipe making it conduct much better and making it more efficient.

 

[Mur Huwcun]

we are the same, prevailing east wind does hit us but as you say its been mild so far, not checked brine temps in ages, its usually around 8-9 recovery i.e goes out at 0-1 comes in at 9-10.

it has improved the longer its been in, im sure this is to do with the ground settling around the pipe making it conduct much better and making it more efficient.

Brine here seems settled now on about 5-6 in and 0-1 out, dont think I’ve seen any more recovery than about 5 degrees but as you say I think it’s improving every year or were getting used to using the system and still plugging gaps around the house!!! I did roll another 100mm layer of insulation in the loft last summer!!!

 

[Farmer_Joe]

ive got 100mm kingspan floors, 50mm behind block lining down stairs, 75mm between timber std wall upstairs and 300mm of rockwool in loft, i will check brinetemps

 

[Mur Huwcun]

ive got 100mm kingspan floors, 50mm behind block lining down stairs, 75mm between timber std wall upstairs and 300mm of rockwool in loft, i will check brinetemps

We‘ve only got 50mm kingspan on the floors in old stone part of house or we would of lost too much headroom but the new part has 100mm under the slab and another 50mm under the floor screed.

 

[Farmer_Joe]

Ha ha I had to compromise slightly on one my rooms which had the highest footings, barn is slightly on incline, it only got 75 it’s still better than nowt

 

[Mur Huwcun]

Ha ha I had to compromise slightly on one my rooms which had the highest footings, barn is slightly on incline, it only got 75 it’s still better than nowt

Well I was going to kango/break the finish floor concrete off the old part to gain a bit but builders were not keen incase I disturbed too much!! Ceilings would of been okay loosing another 50mm but stone door lintels were against us!!! Hardly have UF on in lounge, just run log burner which helps a lot!

 

[JD6920s]

We‘ve only got 50mm kingspan on the floors in old stone part of house or we would of lost too much headroom but the new part has 100mm under the slab and another 50mm under the floor screed.

Does that actually work effectively, having two lots of insulation separated by concrete?
Would it not be better with 150mm between the sub floor slab and the screed?

 

[Mur Huwcun]

Does that actually work effectively, having two lots of insulation separated by concrete?
Would it not be better with 150mm between the sub floor slab and the screed?

To be honest I hadn’t thought about it, it was the way set out in the plans by the architects and the way the builders usually do and what the installers and building regs said. Building control actually asked about the insulation. The old house actually has about an inch of white polystyrene type sheets under the floor slab aswell as I dug a trial hole when we were contemplating lifting the whole lot.

 

[Steevo]

How do air source heat pumps compare to ground source?

 

[foxbox]

Dont do it, you'll be sorry. GSHP's work with underfloor heating not radiators. Who is going to pay the enormous electric bills and live in a cold house. As a landlord you must provide a decent heating system in a rental property. The idea behind the RHI is to offset the electric bills otherwise no-one would do it. They will install the cheapest system available with the shortest ground loops possible and walk away with your money. Do it yourself with underfloor heating and keep the RHI yourself to pay back the cost of the system. About 6/7 years.

As others have said there's no reason not to run a GSHP system with traditional radiators; it'll work with no trouble at all. We're heating a large, old farmhouse, 2 holiday lets and a cottage with a single GSHP and district heating system and have no trouble at all. It also heats hot water too and will happily supply 55C water at over 20 ltrs a minute from taps which is ridiculous compared with the oil fired units it replaced.

We installed ours a few years ago and although the cost was huge the payback is very significant; we're effectively being paid to heat our properties for the 20 years after installation and will be in profit long before we reach the end of that period. If in a worst case scenario we only break even after 20 years we're still far better off than we would have been burning oil and changing boilers etc during that time..

If a company is prepared to do this there is obviously still a margin in it but I'd be wary as @rogeriko says about their specification as there is a lot of incentive to cut costs. If you're comfortable with the concept and the technology it would be sensible to look at it yourself; banks are not afraid of backing these types of project anymore if the figures stack up. Be careful though; I'm aware of a couple of companies that have gone bust in this area recently so do your homework before you get too committed.