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Pompe à chaleur


sueyh
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We had a gas heat pump in the United States.  It was a new system we installed in 2017.  This is the type of system typically installed in the South where winters are not normally THAT cold.  Heat Pump systems are not recommended for northern U.S. states as the winters are too cold.

However, winters in the South have changed in recent years.  It is not uncommon to get temperatures of 12 to 15 degrees (or even less) Fahrenheit several nights in a row, multiple times in any given winter.  When the temp drops to 20F or below, the heat pump system would stop working and switch to emergency auxilliary system - ELECTRIC !  This happened to us on multiple occasions. It costs a great deal of money when the system runs on auxilliary electric heat.  It isn't meant to do that on a regular basis (each winter).

I'd be very careful and do lots of research before I made such an expensive choice.

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Well, I have yet to be convinced that they can operate efficiently below, say, -5 degrees though some say -15. Whatever, the colder it is the less efficient they are and the more electricity they use to compensate.

Perhaps they might be OK for hot water only but not for heating. IMNVHO, of course.

So round here, not a lot of use.

One does see a few system installed but often, I suspect supplemented by either a wood or wood chip fire
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I assume you are asking about an air-air or air-water heat pump rather than a ground source heat pump since those are the heat pumps that are being heavily promoted?

I would agree with woolybanana and am equally unconvinced by their efficiency and possible savings in Northern France of air source heat pumps unless your property is a new build/very well insulated. Once the temperature gets too cold there is little or no heat gain over standard electric heating.

However, I do believe a well-installed ground source heat pump, probably with a vertical bore, would provide an efficient system, but at a much greater cost.

If you want to see a large selection of user reviews, there are plenty on the French equivalent of Which? Search for "site:www.60millions-mag.com pompe a chaleur forum" Of course, you will have to recognise people tend to complain more on such forums rather than posting praise. But you will find a lot of general advice, if you work through them including many reporting later expensive service/parts problems never mentioned in the sales talk.

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We have an air-air system (originally 'reversible' which has had to be partly replaced once (about 8 years ago) and entirely replaced once (4-5 years ago). I would categorize it as a disaster.

It was originally installed in 2004 and we 'inherited' it in 2006. I would never recommend it to anyone. Not least because it sucks up electricity. I'm not sure what % goes on it and what % goes on everything else, but our edf bill averages (last 6 years) €3500 (150m² South facing, thick stone walls).

We got chatting to the engineer who last serviced it; he also said he would never recommend it to anyone!
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I might have posted something about this some years ago but there was a retired engineer in Birmingham who was very attached to his old house, despite it being extremely inefficient from a heating point of view. So he challenged himself to make it as near to 100% efficient as possible.

He insulated everything to the N'th degree and almost reduced his heating costs to nil. This was without solar panels, selling power back to the grid, etc - just purely with insulation. He reckoned he could heat the house to a comfortable level with a candle in a downstairs room. Obviously there was a significant cost to the insulation material but his point was that if all properties were given this treatment - especially new ones - the average cost would plummet and the national energy saving would be enormous.

So yes. Start with the insulation.

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Our apartment was fitted with 3 electric radiators as standard when we bought it - very unsatisfactory for keeping us warm in cold weather, especially as one was positioned directly behind the kitchen door, so couldn't be used.

We had reversible aircon fitted 8+ years ago and find it excellent. We have only one unit fitted, in the bedroom, and leave doors open throughout the apartment and find it heats the whole place very well and cools it well in hot weather. Our apartment faces south, so we benefit from heat from the sun in winter too.

We chose a local company to install it, recommended by several friends who had had aircon fitted by them, and went for the quietest model at that time - Toshiba. As it’s in the bedroom it has to be quiet, and it is.

Our electricity bills went down by a lot and although summer electricity usage rose, our annual electricity bills were reduced by a significant amount.

The apartment block is double-glazed and extremely well insulated. I agree with others that insulation should be the first thought, regardless of the heating system.
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I would never install air conditioning.

It should be banned for the sake of our children and grand children.

If you can't deal with the heat, do move to hot areas. Or move away from hot areas.

I totally agree with insulation. It really is the most cost effective way of keeping warm. As well as getting used to wearing more layers of clothing inside.

PAC....I would not invest personally. Someone will nick it.
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[quote user="alittlebitfrench"]I would never install air conditioning.

It should be banned for the sake of our children and grand children.

If you can't deal with the heat, do move to hot areas. Or move away from hot areas.

I totally agree with insulation. It really is the most cost effective way of keeping warm. As well as getting used to wearing more layers of clothing inside.

PAC....I would not invest personally. Someone will nick it.[/quote]

So you don't have aircon in any of your vehicles because if it's too hot you won't drive it [:D]

So much of what is spoken about on forums relates to older tech, clearly missing that newer improved versions may surpass the performance of units 15-20 years old or more.

You cannot rely on what others say because they have a different house in a different location and fitted by a different person who may have fitted a warm climate version too small just to come in on price, too many variables.

When I worked in Sweden I was amazed to see air source heat pumps in use so close to the artic circle but those units are designed for that environment.

Whilst air conditioning isn't that efficient 20-22% heat pumps are 300-500% efficient. That said evaporative airconditioning units are under development that take aircon to around 40% and no nasty gasses being used (so far). the units are a bit larger but so much better all round.

Still agree that insulation is the first step.

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