1kW of electricity consumed consumed, 4.8kW of heat for the house of which all but 1kW from the ground. So you get 4.8 kW of heat for 1kW consumed. I don’t know how you want me to describe that in terms of efficiency but it’s certainly not marketing rubbish.

Has the OP even got a garden? 😆

So looking at your links, Don. If Clover wants to spend around £1000 then my suggestion of an air/air heat pump rather than gas for automatic/on-demand heat is valid, especially if it’s mainly used when the outside temperature is positive – havin g first looked at how cost effective insulating might be.

I did the assessment using my house measurements and came up with 24kw gas boiler requirement.

Passive house is beyond budget – and would need adapting for 200 year old Millstone grit laithe barn farmhouse. For which I have only just obtained planning permission for double glazing (listed).

During the winter wood fired heating is the way to go but now it’s too much hassle to raise the temperature by a few degrees for a short period. Something automatic for winter mornings would also be bliss – the frost on the inside of the windows is pretty but slightly impractical.

Following links now…

I have fields!

Yes, why not edukator? If it fits the OPs bill. With a bit more info, the problem is a problem of warming up the living space while the woodburner is warming up (too much repetition…). There are limitations on the insulations due to the nature of construction and listed status.

For which I have only just obtained planning permission for double glazing (listed).

Where are you?
You are going to be a bit restricted on what you can do, but there are solutions.
I’d also look to improving the insulation further where possible, these guys have a lot of good advice on areas to improve.
I can only look on the insulation side, heating solutions are too complicated for my simple little mind. 😉

edukator – we’ve done this before, passivhaus is all well and good, but it is completely impractical as a retro fit solution to an old building.

yes maximise insulation and draught reduction, but there’s no way you can re-fabricate a gritstone building (or an 18th C barn) to have 0 vent loss, maximum solar gain and tiny U-values.

Your 1kw of electricity produces 1kw of heat. The rest is solar energy stored in the ground. If you can make 5kw of energy from 1kw of electricity then you are the messiah!

You use 4kw of heat to heat your home. Most of that is produced by the sun the electricity is used to convert it.

Your 1kw of electricity produces 1kw of heat. The rest is solar energy stored in the ground. If you can make 5kw of energy from 1kw of electricity then you are the messiah!

You use 4kw of heat to heat your home. Most of that is produced by the sun the electricity is used to convert it.

You are being incredibly pedantic (and probably wrong as much of the electricity is used in pumping etc), where you only have to pay for 20% of the energy used, it is a perfectly reasonable claim. Only other solar and wind can make an equivalent claim.

pedantry aside, Im still not convinced of those high COPs in ideal conditions let alone for the majority of the time.

but there’s no way you can re-fabricate a gritstone building (or an 18th C barn) to have 0 vent loss, maximum solar gain and tiny U-values.

Some nice wooden shutters in keeping with the look of the building. 😀

I heard they cost an arm and a leg, and I wouldnt trust the importer 😉

pedantry aside, Im still not convinced of those high COPs in ideal conditions let alone for the majority of the time.

I have see higher audited ones, albeit taking into account cooling for modern buildings, cops of 4 are being contracted for by providers on big builds.

I don’t I’ve heard that that particular importer doesn’t do wooden shutters. 😛

No I’m a realist. I fit heat pumps too, they are massively mis sold which is one of the reasons that the RHI payments have been with held.
To even suggest fitting one in an old property with radiators is ridiculous.
They are sold as being 400% efficient etc which is a lie. You cannot create energy surely tat is a basic law of physics.
Pumping usually accounts for a fraction, modern grundfos pumps tell you the energy usage on the front. Most of the electricity will be used raising the domestic water temperature probably.

And pleased with the pedantic tag too!

I have see higher audited ones, albeit taking into account cooling for modern buildings,

thing is it should be immaterial what building it’s installed in, its a simple calculation of net energy gain. How it’s used can be maximised for the building fabric.

I just am very sceptical of what the average COP of the system would be over a day. I doubt it would be within 75% of the cited COP.

And of course it’s pegged to elec costs. big bad in my book 🙂

They use less paid for energy than they produce that is what people in the real world care about, RHI isn’t being withheld although take up across the board has been much lower than DECC anticipated mainly because both GSHP and Biomass simply do not financially stack up against gas unless you make pretty heroic inflation assumption. With the possiblilty of shale gas keeping gas prices low, it is difficult to make those assumptions.

EDIT: Cops are calculated by comparing actual metered heat to actual electricity usage so real world numbers and cover the whole day.

If mains gas were an option, Id never recommend going for an alternative energy source (except maybe solar thermal added to a tank).

Gas will be cheaper for at least the next 20 years IMO.

Its Oil and Elec which are the ones for renewable to beat. Its a smaller market than the whole UK, but its still a big enough market. And the reason Im training up to get into it in 3 years or so. Round these parts (rural worcs) Oil fired CH/Agas is the norm. Its a big market to to have crack at.

Its a big market to to have crack at.

Too small for me, but then I only finance this stuff that is why I am focussed on the commercial sector as I see very low take up in the domestic market for a few years yet.

mefty, mind if I pm you. There’s a business thang that may be of interest to discuss with my “other hat” on.

No problem

The geologist in me says that ground heat is from both solar warming and nuclear fission.

In my friends house with a heat pump the ground water is 10-12°C and the under-floor heating runs at 25°C or less. Why should he doubt the COP claimed?

If the house is millstone grit how about insulating walls on the inside. Use 90mm of recycled polyester behind 22mm pine floor boarding for R3 (with the wall) or rockwool backed plaster board or even a multi-layer insulator behind wood or plasterboard to reduce the interior space lost to 7cm.

Polyester is about £8/m2 and pine £6/m2. Not to all tastes but it looks and feels cosy. Do something with the walls, double glaze and make sure there’s 350mm of insulation in the roof and you won’t need a 24 kW boiler.

ASHP are not eligible for RHI domestically yet because the jury is still out….

Stoner – domestic Biomass will be a good field to be in I think, providing the current commercial RHI doesn’t do a solar on us……..

TBH I think in many cases biomass can be justified in spite of RHI not because of it.

Its those dammned expensive Windhagers that need it 😉

Hello, I think I am looking for a gas boiler + either a heat store or a dursley link thingy then? Where do I find someone on the Yorkshire/Lancashire border who knows about such things?

Anyone on here?

Or anyone who wants a few days of Pennine riding in the Calder Valley?

Clover – recommendations are the best way, personally I would use a store rather than the Dunsley as it will provide greater flexibility in the future. Make sure they understand the controls though.

And yes Stoner they do make sense even without RHI, especially if you look at lifecycle analysis (think that is your thing! Got a couple of spreadsheets that do it for me though!)