Germany is struggling to get people on-board with a green energy movement that involves banning high footprint 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. I’m not sure if that show is accessible… I see no download link but that could be a browser issue)
When I planned my house in 2018, my heat and water installer more or less shoved a heatpump on me, after he heard I wanted heated floors. I gave up on fighting him because I had a lot more on my plate at the time and told him “yeah, whatever, if you think that should be it…”. Cost me like, 10k€ more than the cheap gas heater I had planned, but then again, no gas tank, no chimney, it came to a point where I just didn’t give a fuck.
Last Christmas that dude got a very expensive bottle of whiskey from me.
That pricetag is just the unit and standard installation probably. Pieces are crazy high Here in Germany because the demand is crazy high. Not many heating installers have made the additional qualifications, so those who did can demand practically anything.
It’s not that the people don’t want the technology, the adoption pace is just higher then the supply chains can deliver.
And btw: you don’t need to reach 60°C with a heat pump. That would be pretty inefficient. That wouldn’t prevent installers from up selling you, but that’s a different story.
The issue is that the original radiators were sized to move the necessary n kW into the room with a water temperature of 60C. If you drop the water temperature to say 45-50C, you’re only going to get roughly two-thirds of the heat transfer. The other third needs to be made up somewhere else - additional heating or better insulation.
As you said, running continously is the ideal point for heat pumps. And for a continous load most radiators are big enough. In Germany they were scaled so they could heat up the rooms pretty quickly and then idle for time. Since thats not the goal with a heatpump we can use the idle time to even out the lower peak capabilities. You loose the ability to quickly adapt the room temperture, but with outdoor temperature probes connected to the heatpump this istn an issue. I am in the process of retrofitting my home to a heatpump and that what the engineer told me at least.
A bigger issue seems to be the single-pipe heating vs. two-pipe heating systems, but those are not the majority in germany and should be phased out anyway because they are so inefficient.
And btw: you don’t need to reach 60°C with a heat pump. That would be pretty inefficient.
Thanks for the feedback.
My boiler gives me control of the temp of the water running through the radiators which is independent of the room air temp thermostat. I set the water to ~55°C which seems to reasonably get the air to 17° without running continuously. I mentioned 60° because I figured that temp would enable someone to heat their room up quickly. I wonder why you say a heat pump would not need 60°. I would think the radiators need to reach a high temp like ~50—60° regardless of the kind of furnace. Maybe I’m doing something inefficient. Should I use a lower temp? I could lower the water temp but then there would be a point where the furnace has to run continuously which i would think is inefficient. I’m not sure how to find the efficiency sweet spot.
UPDATE
That pricetag is just the unit and standard installation probably. Pieces are crazy high Here in Germany because the demand is crazy high. Not many heating installers have made the additional qualifications, so those who did can demand practically anything.
Sounds reasonable. So if the demand has out-stripped supply on heat pumps, I wonder if geo-thermal would actually be cheaper than a heat pump ATM. IIRC the digging would be ~€10k (what I think is a typical price for digging a well… could be off). Though I don’t suppose you could use wall radiators with geothermal. Since geothermal water is only ~6° warmer in the winter, hydro-radiant flooring would have to be installed.
Running continuously is usually the ideal point. For heat pumps, it definitely is as the efficiency is highest with the lowest split between indoor and outdoor temps.
The issue is that if you suddenly want more heat, you first have to raise the water loop temperature before that can start pushing more heat into the house.
Systems are usually designed to keep up at perhaps 22-24C even on the worst days of winter; maintaining 17C is a lower target that can be met with less capacity and cooler radiators.
A big part of the cost is probably refitting the heating system. Radiators are designed for water temps that are not efficient for a heat pump.
The default for newly built heat pump systems is underfloor heating but that’s not something you’d install unless you’re ripping out all floors anyway.
The alternative would be large panel radiators or an air/air heat pump with air ducts.
The other one is that a lot of people presume a house needs state of the art insulation, which obviously costs a lot to retrofit.
However in nearly all cases the old radiators work just fine with a heat pump as does the insulation. Underfloor heating and more insulation would make it more efficient, but that is often not worth the money, unless you do plan to do it anyway. When you redo the floors you can then add underfloor heating. Same for insulation, once you redo the roof or have to do work on the walls.
My parents paid about 12k€ 10 years ago - the same heatpump now easily costs triple that. It is a heat pump gold rush over here at the moment.
Confused side note - why does the title link point to a BBC story about South Africa? :) Edit: oh, I see.
To answer the question - I don’t know.
For comparison: installing an air-to-air heat pump for a tiny house in Estonia:
- heat pump unit (smallest unit, maybe 3 KW heat output for 1 KW electrical input), bought at the deepest discount: 450 €
- physical installation (mounting on a rack on a wall) - DIY, 0 €
- electrical installation (running a cable to the outer unit and back to the inner from there) - DIY, 0 €
- insulated copper heat pump pipes, 3 meters: less than 60 € (don’t remember)
- pressing flanges on the pipes with a car brake pipe tool: DIY [note: leave to technicians, this is tricky], 0 €
- sealing and letting the working fluid into pipes - technician’s visit, 100 €
I would imagine that an air-to-water unit costs more (the cheapest are probably over 1000 €, unless you use a pool heat pump which can be crappy), that an average German family lives in a far bigger house (so maybe 3 x more wattage, making the machine cost 3000 € instead), and that they need 3 installation technicians for several hours (maybe 1500 €).
Beyond that - profit?
Tiny house = very tiny and probably new and well insulated.
Estonia also likely has very low labour costs and less difficulty finding staff.
Hydronic systems are usually in the >15kW range, and often have split indoor and outdoor units so you need to both do the refrigerant piping between indoor and outdoor, and the water piping to the radiators. Many systems also include domestic hot water heating as part of the same system, so three separate sets of plumbing.
In most of the first world, purging linesets, vacuuming, and releasing refrigerant is usually ~$500.
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.
I worked in the industry and real-estate.
These houses were never designed to be insulated or airtight, and (controversial take) IMHO often shouldn’t be fully 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.
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.
You are basically correct.
But allow me to rant, for which I apologise. Feel free to ignore, it’s not that interesting, and I’m not an expert.
The main thing is (properly installed) moisture barriers, if necessary increasing ventilation, getting rid of any moisture, choosing the right insulation for the right job, etc.
Eg. rockwool is very absorbant and is even used in hydroponics, but if you pop it in an attic, use a decent moisture barrier, but ventilate it well, it’s not a disaster if it gets a bit moist sometimes. Meanwhile, in an (almost always) damp basement, forget using rockwool. Even using PUR/PIR foam is likely to cause issues, even if you use the best and most professionally installed moisture barrier. Better off using XPS. Meanwhile, when it comes to wall insulation in older houses, spraying foam into the intrawall cavity(inner wall, space, outerwall), can also cause issues.
The problem is that people will hire a company with a load of good reviews. They’re friendly, they’re affordable, afterwards the house is nice and warm and well insulated. Everything’s covered up, so even if you were an expert, it’s not as if you can check if they didn’t half arse their job or if they aren’t well intentioned morons who installed a moisture barrier the wrong way around so it only allows moisture in rather than letting it out… But years later, when the damage starts becoming apparent, when people start falling ill from mould, or the concrete has become so weak so you have a pothole in your living room, the company likely doesn’t exist anymore. And it’s not as if you can hire a company with 50 years experience, because some of these kinds of insulation are quite new, and not everyone has experience working with older houses.
Eg. Lime mortar started being being phased out at the beginning of the 20th century, so it’s no surprise someone who’s ‘only’ 40 wouldn’t know it has different properties than portland cement.
And for professionals who do know their shit, do it properly, and charge accordingly, it’s not unlikely the homeowner will go with the cheaper offer because they don’t think it’ll make a big difference but can save thousands.
Good read and good points. Thanks for sharing/ranting!
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.
If you have a cavity, which a house from the 1920s probably doesn’t have.
He specifically stated he had a cavity. If you don’t you can do external cladding insulation and internal insulation.
They sometimes do, but some of these older brick houses use lime mortar which is far more breathable. Allows moisture in and out. Some older houses are also not that water tight anyway or often have moisture issues.
If you use the wrong foam, it absorbs that moisture. Bad. Think mouldy sponge. If you use the right foam, but don’t ensure ventilation and tackle moisture issues? Still bad. If you don’t mix the foam right or use too much? Possible structural damage. Or the foam’s flammable which is an issue in an old house with old electrics.
The person you’re responding to mentions people doing it themselves with an expanding foam gun, which as someone who worked in the industry gives me the shivers tbh. I mean, maybe they’ll get lucky, but I wouldn’t buy that house. If they used the wrong foam or did it wrong, it’s not as if you’re going to be able to remove it or start over. It’s there forever now.
