Heat Pumps, One for the engineers

[Peter.N.]

The pumps themselves might be efficient but at present using the most expensive fuel know to man, my oil fired boiler costs about 11 or 12p per kwh even at today's oil prices that's almost a quarter of the cost of electricity. Once you get down to below freezing on an air source pump you get around 1 to 1, a ground source pump is better but costs a fortune.

Peter

[Paul-R]

The geek shall inherit the earth.

[GiveMeABreak]

We're off the grid, so have oil heating and we have no complaints.

[CitroJim]

Just seen this tread...

I'm needing new heating installed - currently my elderly gas combi-boiler to radiators is on borrowed time although during it's life it's been reliable - and I'm genuinely struggling to know what's best for a new system.

Instinct, at this point in time, suggests that I should stick to gas. Oil I'd like but it's not an option here.

Grateful your thoughts

[mickthemaverick]

Without going into detail I would keep the gas boiler going for another 2-3 years and then hopefully the cost of ground source heat pumps will be more acceptable. At that point I'd make that switch.

We put in a new gas combi in 2013 and I intend to run that for another 3-5 years at which point a ground source pump will be the way to go. We do have the advantage of living on a hill which will make the installation easier as the house ground level is 4 feet below the surface where we would have the excavations done and thus a smaller uplift will be required!

[bobins]

Do research whether you'll need bigger radiators though as the heat output from the heat pump may not match that from a traditional boiler.

[RichardW]

You need a lot of ground to make a GSHP work (it needs like 1000m of pipe...!), and the cost is likely to remain prohibitive for a long time to come. Much better solution if you can manage it than an ASHP which suffers from low COP when the air is cold (just when you need it most)

As you've got mains gas, just get a new combi in Jim, lowest cost at present both for install and running. In my mind very unlikely that gas boilers will be mandated out any time soon - and even if they are stupid enough to do it, then an industry in fixing old ones rather than just sticking a new one in will spring up. It will suddenly be worth forking out £500 on a new heat exchanger say, when the alternative is £10-15k worth of ASHP.

[Peter.N.]

That is still only viable if the cost of electricity goes back to something like it was. Gas is without doubt the cheapest fuel - at the moment. Where are they going to get all this green hydrogen from for a cost that makes it viable?

Peter

[myglaren]

That is still only viable if the cost of electricity goes back to something like it was. Gas is without doubt the cheapest fuel - at the moment. Where are they going to get all this green hydrogen from for a cost that makes it viable?

Peter

Indeed. Although I hope they can make it all work I fear that there is still a great deal of work to be done on Solar, Wind, Heat pumps and Hydrogen - see the Hydrogen Thread, particularly this ladies findings.



She is as sceptical as I am.

[Dormouse]

Do research whether you'll need bigger radiators though as the heat output from the heat pump may not match that from a traditional boiler.

Totally agree. I oversized all of the ground floor radiators, not with Heat Pumps in mind specifically but with lowering the Boiler Output Temperature to aid boiler efficiency. It took several years but I finally developed a Boiler Economiser that I fitted 2 years ago that has made great improvements in gas consumption and I won't be changing from Gas anytime soon after a disastrous attempt at All Electric in our last house (new build and completely designed around Insulation and Electric Heating).

[CitroJim]

Thanks all, that's hugely helpful and really appreciated... Especially the advice to oversize the new radiators

GSHP is not an option for me as my garden is smaller than the average window box... One scrap TU engine and an old Xantia rear subframe has filled it almost to capacity After the garage, that my house had nearly no garden was a big reason for buying this particular one... I'm no gardener and never will be...

[mickthemaverick]

I'm no gardener and never will be...

I thought you were rather good at sewing seeds Jim...

[Hell Razor5543]

I'm no gardener and never will be...

No, but I would not be surprised if you knew how to sort out a Gardner or two!

[Stickyfinger]

Cast iron radiators are ideal for heat pump systems.....funny how things go around....

[CitroJim]

I'm no gardener and never will be...

I thought you were rather good at sewing seeds Jim...

But never wild oats

I'm no gardener and never will be...

No, but I would not be surprised if you knew how to sort out a Gardner or two!

Yep, reckon I could James, especially if it runs on diesel

Cast iron radiators are ideal for heat pump systems.....funny how things go around....

I'd love a houseful of cast iron radiators but alas in my IKEA-themed house I don't think they'd blend in very well and I doubt my upstairs floors could carry their weight...

Am I correct in thinking they act as a sort of storage heater and hold on to a lot of heat long after the source of that heat has ceased?