Britain’s earliest central heating boilers, installed between the 1960s and 1980s, typically ran at very high temperatures. This has set up an expectation that a well functioning heating system should be able to deliver strong blasts of heat on demand, Sowden says. By contrast, a heat pump gently maintains the ambient temperature of a room by using more efficient, lower-temperature top-ups through the day.
“People think a heating system isn’t ‘on’ if they touch a radiator and it doesn’t burn their hand,” he says. “But it doesn’t need to be belting out heat to keep a room at a comfortable temperature.”
So, what we’re being told is that in the European country with the most variable temperatures over the short term – which I think Britain probably is, recall George Mikes and the comment that the British talk about the weather because we’re the only people who have it, everyone else has climate – we should kill off a heating system that can deal with variable weather and adopt one best suited to climates?
What fucking joy, eh?
Presumably a system that is more efficient will also be cheaper to run.
So let those that wish to, install a heat pump and reap the benefits. After a couple of years, if those benefits are clear, then the rest of us can make our own choices.
Personally I keep my central heating on permanently and with the thermostat keeping a constant room temperature of 65 in the winter. I’ve just checked my data logs and the boiler is on for two hours total a day at most, on the coldest December and January days. I’m happy to be shown how a heat pump can do better for less cost.
But it doesn’t need to be belting out heat to keep a room at a comfortable temperature.”
True, but as it’s running at perhaps 35C instead of 55C the radiators need to be a lot bigger to give off enough heat, and its going to be slow acting too so expect it to be chilly for a bit after opening a door. Because heat pumps are low temperature difference heating even getting up to 35C is going to be a struggle on a cold winters day. Either efficiency falls and you use more electricity or you accept an even lower output temperature. Often underfloor heating is preferred to get the big area to give off the required heat at a low temperature, but even then on a cold day the heat pump efficiency plumets and contributes little to what then is essentially “simple” electric heating.
It works but it all adds up to an expensive installation that becomes inefficient to run when you need it most. The hidden problem is that drop in efficiency during a cold snap leads to a particularly high peak electricity demand that we have no way of suppling, so the lights go out across the country and of course the heating stops too.
Heat pumps operate with an output of 50C or 55C, therefore need to run continuously, and more importantly require a large heat surface area to maintain comfortable ambient temperature.
This means very large radiators, and/or lots of them. The best method is underfloor – tiled – which heats almost the entire footprint of living space – water circulates through the pipe work at around 40C. This is only practical on the ground floor, but heat rises so heating upstairs can be augmented with radiators – additionally all inside doors should be left open whenever possible.
The heat delivered by the heat pump, and electricity consumed, will vary with outside temperature, its effectiveness decreasing with fall in temperature, but a good make should maintain indoor at around 20C Dixon to -7C outside.
There is no ‘one size fits all’. Output, and therefore size, is chosen according to internal space that needs heating and the ambient temperature desired. Insulation plays its part, but it is not the decisive factor. If the heat pump is under-rated for the size of the property and number/size of the radiators, it will not provide a comfortable temperature.
Heat pumps are not good for hot water. Many are used to demand boilers, but a heat pump will need a hot water cylinder fitted with an immersion heater. They take a time to heat up a tank of water, are cannot quickly reheat the tank once water is run off. And while it is heating the water, it is not serving the central heating.
They are effective if the correct rated pump is chosen, and installed properly with adequate heating surface. Running fist is no cheaper than gas. They require outside space and are noisy. In cold weather they ice up and have automatic defrost which means they need somewhere for the water produced to flow away.
I had one installed in property in France. It was economical only because the alternative was oil or LPG, there being no piped gas available, and electricity in France (nuclear) was low cost.
If the govt is pushing heat pumps, it’s time seriously to consider installing a wood-burning stove.
INSULATION, INSULATION, INSULATION
I am involved in a heating research project. It is well understood that heat pumps are only effective (comfort and price) if the house is insulated properly. Bloke in Wales reports that his house is warm with only 2 hours heating a day. I guess that he is very well insulated and a heat pump would be fine.
My own 1930s London yellow brick terrace was actually designed to be drafty, those airbricks at the the front and back let in the cold air so the coal fires can draw well! The single brick skin lets heat out almost as fast as I can put it in.
The first step in a migration to carbon free heating is insulating the walls (roof is new and OK) with either internal (OK) or external wall insulation (preferred).
Obviously as Tim Worstall reader I believe in free markets but one has to note that the problem in London is finding a builder who is available and competent at any price. The information asymmetry and lack of alignment of incentives creates a market for lemons. To its credit the Government understands this problem and is trying to do something about it – hence the research that I am involved in.
However the normal rule that anything to do with building houses in the UK is totally f*cked still applies and there is little prospect for real change.
TMB @ 8.40. Good luck with that idea. My guess is that in the not too distant future the eco nutters will lobby to ban them due to the amount of ‘particulates’ or some other nonsense reason.
A German website I peruse had an item last week that servicing a heat pump costs around EU300 a year, considerably more than the £45 to service my gas boiler. And when I replaced my 40 year old Ideal Concorde boiler for a ‘modern, more efficient, condensing boiler’ my gas bill went up.
Instead of finding ever more ‘creative’ means to go green or net zero, tell them to fuck off.
You come back from shopping or walking the dog in the driving winter rain. Your hands are numb and your trousers have that annoying icy wet band where your jacket has dripped onto them. What you want more than anything else is a nice cup of tea and….
Well, what you don’t want is a nice ambient temperature of 17.C that will keep you alive and save the planet.
We have an oil boiler and coal, because we are normal heterosexual people.
” The best method is underfloor – tiled – which heats almost the entire footprint of living space – water circulates through the pipe work at around 40C. This is only practical on the ground floor”
My friend had a house built with a ground source heat pump installed and she has upstairs underfloor heating so it most definitely is practical. Though she says having now experienced living with the system for over 10 years she wouldn’t have bothered with the upstairs underfloor, except maybe for the bathroom, as the heat moving upwards from the ground floor is more than enough to keep the first floor warm, and the extra heat from the bedroom floors makes it too hot.
Obviously it is adequate for my comfort levels, but it was installed at least 30 years ago by the previous owner. So the usual “lets insulate everything” cowboys would no doubt tell me it needs redoing.
Your hands are numb and your trousers have that annoying icy wet band where your jacket has dripped onto them…
3rd best hiking investment I’ve made, after a Goretex jacket and top quality boots.
https://www.amazon.co.uk/gp/product/B001E5SO5S/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1&psc=1
Not cheap at £450+, but money well spent.
– a heat pump gently maintains the ambient temperature of a room by using more efficient, lower-temperature top-ups through the day.
Which will be great when they turn your power off several times a day via the smart meter because there isn’t enough electricity to run all this shit.
This has set up an expectation that a well functioning heating system should be able to deliver strong blasts of heat on demand . . .
Yes, we have an expectation that a heating system should provide us with heat ranging from hot to frost-guard, according to our desires. We don’t need some state-corporatist cunt trying to sell us the idea that “low temperature” heating is anything other than not-a-heating-system.
Fuck off.
A chap for whom I have an LPA lives in sheltered accommodation – it’s a small one-bedroom, one sitting-room, kitchen, hall and bathroom, very well insulated and double-glazed flat. His housing association refitted the place with an air-source heat pump system. Prior to the refit, the place was heated (admittedly not terribly well, but perfectly liveable) by storage radiators and his monthly electricity direct debit was £41.
His electricity supplier (OVO) has just proposed increasing his direct debit to £330 – which, as he lives on his state pension and a small occupational pension, will bankrupt him. I’ve been trying to do something about it, but OVO have the worst telephone system I’ve ever encountered.
You can count me as “very unconvinced” about the desirability of heat-pumps.
Ten years ago I lived for six months in a well-insulated new-build in the Grampian mountains which had underfloor (oil-fired) heating on the open-plan ground floor. My conclusion: never again. The open plan floor meant zero privacy, zero segregation of functioal spaces, and the most significant – to get the “living room” area comfortable you had to wait for the entire house to warm up, as it was impossible to close a door to isolate the area you were in.
Plus cold snaps. Several times over the winter it got so cold I ended up making a blanket tent over the bedroom radiator and huddling inside to stay warm.
In contrast, the flat I live in now in a 200-year-old stone house, I close the living room door and stay in there cosy at 18C most of the day, only venturing out to the kitchen for a cup of tea, or going to bed, both of which are set to about 10C. Some days the warmth from the morning sun coming through the window gets the room warm enough before the heating starts.
” OVO have the worst telephone system I’ve ever encountered.2
The senior management and owners of OVO should all be lined up against a wall and shot, their families sold into slavery and their houses razed to the ground and the land salted. A bigger pile of human excrement it would be hard to find.
“His electricity supplier (OVO) has just proposed increasing his direct debit to £330 – which, as he lives on his state pension and a small occupational pension, will bankrupt him.”
Poor sod. Your figure threw me for a moment, inasmuch as I pay same supplier £140/month for Leckie – which runs a couple of Dimplex/fan heaters, lighting, cooking and our domestic water pumps. But then LPG (heating) accounts for an additional £2k/year and my trusty wood stoves a further £1.5k/year. All of which of course pales compared to the cost of having to gut the house should I want to accommodate an air/ground-source heat pump. If I have to at some stage in the future I will grudgingly make the necessary adjustment – have always done my duty and paid my way. What really pisses me off, however, is that the same mugs will doubtless also have to subsidise the transitional cost for the two-thirds or more of our population that seemingly doesn’t have a pot to piss in. First world aspirations with a third world wallet.
@BiND – I’ve got a pair of those overtrousers, was £450 a typo, or were you including a full set of outdoor gear?
@Jim I used to work with a guy who had underfloor heating downstairs. They took the kitchen and hall floor up twice before finding the leak…
There are advantages to having pipework where it can be got at without digging you house up. Because shit happens…
Chris,
That’s for the full set of outdoor gear: includes lightweight Goretex top and Salomon boots.
I like Salomon boots, too, though I’m currently using Karrimor, as the Salomons have got quite pricy.
We now return you to our economics/central heating discussion 🙂 …
Local electricity company was running ads promoting heat pumps showing a normal family and their home talking about how great it was, turns out the guy was a heat pump installer. In fairness they did say that in the advert, but not exactly a glowing endorsement
OVO are literally the worst. Only way I’ve found of dealing with them was to cancel the Direct Debit completely and pay the actual bill as received, which was no where near their Direct Debit demands.
The sooner the electricity market gets competitive again the better and OVO will hopefully feel the wrath of those trapped within its icy bonds (being a former SSE customer moved to OVO against my wishes).