Pompes à chaleur

[MAD87]

I'm seriously considering having a pompe installed after last winter's experience - €3,000 in gas bills, just for the coldest months. We installed a new boiler about 3 years ago + radiator thermostats and extra insulation, so thought all bases were covered. I'm not prepared to let it continue but OH ius balking at the cost (around €16k after grants. It'll be written down in a few years if the experts are to be believed. I'm told energy costs are roughly €3 per m², which would would work out at less than €350/year for electricity. Even if it was double that, it would be a win-win situation.
Or am I being gullible?

[niemeyjt]

You will probably need to factor in a change of all your radiators to larger ones as the circulation water is cooler.

Irrespective of the costs, though, I suspect this is the way we will all be pushed to go.

[MAD87]

I'm told they can use the same rads.

[Lori]

I can only relate our experience with a brand new pompe a chaleur in the rental home we rented from June 2021 to December 2022. The rental house was a very old village house, but it was mitoyenne on two sides (double glazed windows, heavy entry door(s). There were radiators in all rooms.

We were the first to use the new heating system. The minute we turned it on the electrical circuit breaker would cut off. The system was not usable.

The EDF line to the house was 12kwh. The owner called EDF and they came out. They said they could not bring in new, stronger electrical lines to the house (I can't remember why). So, we were forced to take an 18kwh account with EDF for 100m2 house with only basic electrics in it. All this took about 2 months. During this time, we were freezing.

Then, once we finally got the 18kw going, we'd have to set the heat to around 27 C for the house to stay barely warm (20 in the house). We complained to the owner about this and the guy that installed the system came out, checked it and said it was working normally. No explanation as to why when the heater is set to 27, the house is never warmer than 20. That cost a FORTUNE in electricity. It was really ridiculous.

From our experience, we would never ever buy one.

[L Austin France]

I've not seen a recent installation using a PAC to replace an oil/gas boiler but, as a long retired professional building services design engineer, I'd be inclined to check the credentials of the people designing your system.
I'm in the market for two more air/air systems but have yet to find a company who can convince me they are no more than rule of thumb installers. Recent experiences have shown that accepting any quotations from these 'engineers' would have been disasterous. It's not just my opinion as, just to be sure & talking the same language, I have checked out every quotation & specification with the PAC manufacturers technical dept who have without exception all agreed the proposed systems would not perform well at low outside temperatures.
It seems to me that the 'few questions asked' goverment aid available is bringing out the chancers who see quick bucks to be made from gullible punters so my advice is caveat emptor & check out any company before parting with your hard earned dosh.
Anyone with a decent newish oil/gas fired system could well find that,with the grants available, spending less money on more/better insulation would be a better way to go.

[Blaze]

Our granite former farmhouse has exposed stone in the hall which is on the north side. The house is built on sand and there are no foundations as far as we know. There's not a lot we can do about the floor but we're getting the stone walls lined an insulated in a couple of weeks and it should make quite a difference. We've already added extra insulation in the roof spaces, and the rolling shutter on the wooden front doors and the door curtains I made from thick polar fleece have made a heck of a difference. No more condensation running down the inside of the door.

[elsie]

@MAD87: You should be able to calculate how many kWh of energy your 3000€ gas bill is equal to (I assume the bills have the figures for that?)

Then, if you assume, say, you will get a coefficient of performance (COP) = 3 from your heat pump, you then know how many kWh of electricity you will need as, for a COP = 3 you would get 3kWh of heating for each 1kWh of electricity.

From a quick search and some ballpark figures, it looks as though the cost of town gas is about 0.11€/kWh (?) If electricity is 0.22€/kWh (?) then for a COP=3 your usable heating energy cost would be 0.22/3 = .073€/kWh, so you bill would reduce to 2000€ from 3000€. If it is the more expensive liquid gas then the savings would be greater.

[L Austin France]

From a quick search and some ballpark figures, it looks as though the cost of town gas is about 0.11€/kWh (?) If electricity is 0.22€/kWh (?) then for a COP=3 your usable heating energy cost would be 0.22/3 = .073€/kWh, so you bill would reduce to 2000€ from 3000€. If it is the more expensive liquid gas then the savings would be greater.

So if these figures are correct (& I've no reason to dispute them) it'll take 16 years, at present costs, to recoup the initial 16k outlay & by this time the original equipment will be worn out/obsolete but the installers mansion/s will have appreciated in value

[RobertArthur]

@ Lori, " they said they could not bring in new, stronger electrical lines to the house."

The answer is that as from April 2011 the maximum puissance souscrite in single-phase has gone down to 12 kVA. The EDF/ERDF/ENEDIS used to do their branchements monophasé also in 15 kVA and 18 kVA. Above 12 kVA the only option is a three-phase connection.

Making life not easier: our little green friend, the French smartmeter by the name of LINKY. It doesn't like overloads at all. Even the so called inrush currents of electric motors (pompe à chaleur) during several seconds are prone to trigger LINKY, everything off.

Bird's eye view: in several European countries the grid is almost overloaded. Several regions are "full": new connections almost impossible. This goes for the countrywide high-voltage network and the lower voltage regional grids. Doubling the capacity before 2030 and in 2050 the grid should be capable to cope with three times the now existing capacity. Everybody an electric vehicle and a heat pump? I doubt it.

[Quiksilver]

Hi Mad, be wary of 'miraculous' savings, especially with one of those pumps installed on an exterior wall. We've got a refrigerant gas/wet underfloor heating system and excellent insulation, and although it's good, producing a comfortable heat, it's nowhere near as cheap as it was made out to be. With electricity prices set to rise steadily, when all's said and done, it's electric heating