Pompe à chaleur - are they any good?

[Headers]

My neighbour who is aged and on low income has been persuaded to talk to someone about installing a pompe à chaleur. She currently has a very old central heating system run on fioul. She spends 1000 euros(oil price depending) on her supply every 3 months! A large and drafty house with 15 old radiators most of which are set to frost free. She also has an old open chimney so a lot of the heat goes straight up that!
She is having roof insulation installed very shortly.
Will she have to supplement the pompe with another heating source for her shower/kitchen needs?
I’m not sure how much this will cost. She will be able to apply for some subventions.

[RobertArthur]

Your neighbour has to think twice before signing anything, see also the thread about solar panels in the building section.

First of all: using more (perhaps) cheaper energy to heat a large and drafty house is not the way forward. Insulation first.

About the technical aspects: an overview in the French magazine SystèmeD and a book by the CSTB. More advice from these government sources, also about subventions.

Old radiators: probably designed for water temperatures of around 65 C. The problem with the standard air/eau sytemes is that they have an output temperature of about 45 C. Change the rads for special low temp devices, or install a very expensive "double" pompe. Maintenance can get a problem with this high-tech technology.

[tagh]

And the running costs; round here they are not effective much below zero degrees so you start burning electricity to compensate.
The grants to install may seem generous but the personal outlay is still pretty steep and beyond the means of many folk.

[RobertArthur]

Electrics: the higher powered systems need a three-phase connection to the grid and a higher puissance-souscrite. Rewiring of the tableau elecrique necessary, expensive

[DaveW]

If you get the pre-requisites right(insulation,plumbing, wiring,etc) heat pumps can be a very good investment with a fairly quick return on that investment. I have a split unit in all living rooms/bedrooms and am very pleased with them. I have no other source of heating/cooling, though don't get many below zero temperatures.

[Spardo]

I would have said air to air heating/cooling, which is what we have, but not sure that would be suitable for a large house. But the dual purpose for summer and winter is very useful, and economic.

[Headers]

Your neighbour has to think twice before signing anything, see also the thread about solar panels in the building section.

First of all: using more (perhaps) cheaper energy to heat a large and drafty house is not the way forward. Insulation first.

About the technical aspects: an overview in the French magazine SystèmeD and a book by the CSTB. More advice from these government sources, also about subventions.

Old radiators: probably designed for water temperatures of around 65 C. The problem with the standard air/eau sytemes is that they have an output temperature of about 45 C. Change the rads for special low temp devices, or install a very expensive "double" pompe. Maintenance can get a problem with this high-tech technology.

Yes I am a little concerned, but she has relatives who will stop her signing anything under pressure and she is canny too. I did wonder about her current rads as they are likely quite furred up. It’s always really warm in the house in the winter months so this info about the running temp is very useful.

The house has old windows and there is always a howling wind going through it so I think I’m going to have to sit down with her and go through what they are proposing. Especially as we are on top of the escarpment and it can get quite cold in winter - down to minus 14

She did want to put in a wood burning stove but even that is technically very challenging because of her chimney which is the most bizarre shape at the top- built in the mid 1800’s.

[Spectrum]

Heat pumps are really designed to be used with new builds, when the insulation can be increased and the pipework easily installed, to retro fit will be very expensive, she may be better looking just to replace her boiler with a self load pellet one, don't no much about them, just a suggestion. We have air/water and UFH but in a new house and its very good.

[Spardo]

We were tempted by pellet, but they are controlled by electricity and when we realised that that would mean replacing our wood burner and that that would leave us with no heat during power cuts, we decided to leave ourselves with the back up.

[Headers]

The salesman came to see my neighbour. She said he was really nice (I no I thought to myself)
He measured everything up. He said it was the biggest house he’d ever assessed.
He thought the electrics would be ok.
Then he told her not to do it as the cost to her would be over 8000 even with all the available subsidies.
He did encourage her to get on with the insulation.
I am very relieved !