Germany is struggling to get people on-board with a green energy movement that involves banning inefficient domestic heating systems (e.g. gas boilers)-- thus forcing people to migrate to heat pumps. A low-income family who was interviewed said it would cost €45k to install a heat pump in their terraced home in Bremen.
That price tag sounds unreal. I am baffled. What’s going on here? I guess I would assume an old terraced German home would likely have wall radiators that circulate hot water. Is the problem that a heat pump can’t generate enough heat to bring water to ~60°C, which would then force them to add a forced-air ducting infrastructure? Any guesses?
(note the link goes to a BBC program that looks unrelated, but at the end of the show they switch to this issue in Germany)
SteefLem@lemmy.world 5 months ago
We have a house from the 1920s. The isolation in these houses are non existent or minimal. I isolated things i could access like the roof. But still i can really isolate the walls because since they are double walls (2 walls with a space between them) there is a lot of debris on the bottom which has to be cleared before they could be filled with isolation (expensive) if thats even possible if not (in our case it isnt) then i would have to put isolation on the outside which is a min of €20k. And i would have to isolate the floor another €8k and even then the house isnt 100% isolated. Then the cost of the heatpump which is about €10k to €15k in our case. And then if i really want off gas i also have to do some sort of boiler for water which i dont really have space for. So all in all it would be cheaper to build a new house then to retrofit my 100 year old house. And there are a lot of old houses here. Heatpumps in its current form are just not feasible for “normal” people.
Squizzy@lemmy.world 5 months ago
Cavity filled insulation is very common and relatively cheap. I know people who did it themselves with an expanding foam gun and multiple cases of foam.
venoft@lemmy.world 5 months ago
If you have a cavity, which a house from the 1920s probably doesn’t have.
Hyperreality@kbin.social 5 months ago
I worked in the industry and real-estate.
These houses were never designed to be insulated or airtight, and (controversial take) IMHO shouldn't be insulated. I lived in a larger old house, and we'd heat a limited amount of rooms. The rest of the house was largely unheated and not properly insulated, allowing moisture to come and go. You simply dress accordingly. That's why people were always wearing multiple layers and three piece wool suits back in the day.
Eg. some old houses use lime mortar instead of cement. Lime mortar is more porous than cement, so it absorbs and wicks moisture. If you insulate that improperly, you're asking for problems, because moisture will build up behind the insulation or get absorbed into it.
Same thing for the roof of an old property. They were designed to circulate air. Water gets under the tiles, the wooden structure get damp, but it's not a big problem, because the air and moisture can evaporate and escape. People will poorly insulate their roof, then end up with disastrous moisture/rot issues, resulting in very expensive structural damage.
TLDR: If you insulate these properties improperly, the chance of rot or moisture issues is not negligble, and arguably you should ask yourself if it's even a good idea to insulate at all, rather than simply adapting your lifestyle and heating a limited amount of rooms.
TBi@lemmy.world 5 months ago
I agree with you. But there are breathable insulation types for these older houses. So they can be used. These are more expensive so should have higher tax breaks when applied to houses that need them.
Also I agree with the wearing extra clothing part. One extra jumper never hurt anyone.