correctly sizing radiators for a ASHP

AIUI solar electricity panels quite like cold. The winter problem is that there's not much light, not the temperature.

Andy

So no plan B or C when the wind fails to blow in 2030?

The 10 years of gas could help substantially with our balance of payments and give us a massive energy insurance policy.

Ground source works better but only if you have enough land for shallow burial of the pipes or you don't have lots of nearby neighbours all drilling bore holes in close proximity :)

I'd far sooner prefer the money to go into home grown nuclear technology.

I might expect 150% return? say 100% heat, + 10-15% electrical power which with a COP of 3-4 to give 150%?

Heh. I have the 13kW version of that heatpump. House not particularly well insulated (quite lossy upstairs; open chimney; windows open a lot of the time for fresh air), but perfectly warm when it's running. We did replace all the rads, maybe 50% bigger in area than the old ones, which were grotty

I uprated to the 13kW for cooling purposes (an ongoing DIY project): 10kW was what the heatloss calcs came out with. There are some efficiency hits in the design - bigger than necessary heatpump; slightly higher flow temps given the radiator sizing; hot water is supposed to be 55C but I've reduced it to 44C which is fine; buffer tank because the installer was lazy and doing an install like it was a boiler (this is however helpful from a cooling perspective)

I'll post 12 month energy consumption numbers in December, but so far bills have been fine.

Theo

Are you sure that's 5C? That's not even a cold winter day. Typical 'design outside temperatures' are -5C to 1C in different parts of the country.

Being a 2000 build your heatloss to DOT should be roughly 30-50W/m2 (2006 would be 20-40) [1]. How many m2 do you have?

To buy the unit itself is £4k+VAT from a plumbing merchant, I'm sure a proper distributor will sell it for less.

Oil boilers are about £3k+VAT.

Not had that with my ASHP. We don't run it overnight, and it'll bring the house up from cold without too much trouble.

In terms of efficiency, the sub-zero days in the winter are relatively few. The days where it's single-digits positive outside are many. The heatpump efficiency is good on those days, and it's fine to pay a slight efficiency hit on a freezing day because they aren't too common. (although Scandinavia have those days a lot more and they use heatpumps everywhere).

OK, so 50W/m2 sounds reasonable. If you are trying to run it like a boiler cycling it on for an hour at a time, that's not going to be very efficient because the more output you demand from it, the higher the output flow temp, and the higher the flow temp the less the efficiency.

My official heatloss calcs: Design outside temp: -1.8C Biggest room was the living room (22.5m2) at 1529W (2.5 outside walls and a loft), 1960s, DG and cavity wall. The other rooms are smaller and less lossy.

The existing rads were about the size of those in the video, but horizontal. The replacements are roughly the same size but double convectors.

It should be OK, as long as you are keeping an even temperature and not cycling it. It won't be able to move the temperature like a boiler does, I agree. How much margin it has depends on how tightly the output is matched to the heatloss (our heatloss was 5.15kW and they suggested a heatpump specced for 9.6kW output, so plenty of margin)

UFH is a good idea, and should be standard in newbuilds IMHO.

Theo

"In the UK, results from exploratory drilling were mostly bad. The drilling triggered multiple small and several medium earthquakes."

Some spots in the USA, suffered on average, three small earthquakes every day, while fracking was actively being carried out (production). That's the reason those spots were shut down.

Others, did not have problems quite that bad, with the fracking materials injected into the ground, causing the plates to slip.

It's the injected material that causes this, rather than just drilling a hole.

Paul

I have worked in an office with air to air heat exchanger units as the only heat source. They appeared to operate quite well through the winter. There are defrost cycles, during which the mode reverses, in order to melt frost on the external heat exchanger. This means that the internal kit blows cool for a while, but not to the extent that it compromised overall heating performance, and they didn't all do this simultaneously. It might be less acceptable in a smaller space.

How does it work with your type of system?

Chris

Has anyone told you that in fact the whole point of fracking is to extract enormous amounts of methane?

..

The reason to ban it is the fear that it might be successful, profitable, completely safe, do wonders for the balance of payments, increase energy security, reduce imports of Russian and middle eats gas by undercutting them on price, generate a nice tax take, and generate jobs in red wall seats that actually create wealth.

That simply cannot be allowed to happen if Britain is to be reduced to economic ruin as a precursor to forcing it back into the EU.

No success please, We are Europeans....

I don't think anyone is denying that ASAP can work well just that the whole system needs to be designed correctly. In the original video I linked the radiator size was physically 3x that of a comparable radiator that designed to work on a 70C flow temperature. Bolt a ASHP to a typical existing system and it's likely not to work too well.

The ASHP hype is that you can get it installed for less than £10K which suggests just bolting it in as a replacement to a gas/oil boiler.

I note that building regulations (for new builds) are for central heating systems with a flow temperature designed for 55C, or less.

Probably huge, but it would make people ask the question 'why have windmills then?' which isn't allowed...

OTOH there may be 100 years.

Not if we want to actually survive as a post industrial civilisation

That's why it must be banned. A Successful Britain outside the EU is Not Allowed

Did I say otherwise? Unless you have bought into the climate change narrative completely, what makes the world warm is not CO2, its solar activity. So cold weather means low solar activity, by definition.

I assumed people would be smart enough to figure that out....

Indeed. In the limit if you go deep it tends towards geothermal energy, and you end up creating permafrost as the rate of winter heat extraction overtakes the rate of summer replenishment.

It is, as are ASHPs. And wood burning stoves :-)

Says who? John Major, Tony Bliar? I don't see anything of the sort.

If you kept up to date, the EU are suggesting reducing red tape for UK import and exports.

If only you stopped being so emotional, and actually engaged some thought before typing such tripe.

By all means provide a cite for such a claim. I know you want to but can't.

You're pretty much a lone voice, where most would say quite the opposite.