ᐅ East-west orientation of the roof surfaces, gas or air-source heat pump

Sorry that my air source heat pump is working so well—I guess I found a great heating installer for it, unlike the others 😉 The neighbors have the exact same house (the company I worked for built three identical houses side by side on separate plots, and I’m the only one with an air source heat pump because I wanted it for my own use. I basically bought it from my former employer. The other two, for cost reasons and since they rent out their houses, use gas/solar systems (solar only for hot water), and we have significantly lower energy costs per year. We only spent about 2000 euros more than the gas/solar system for the air source heat pump setup (all costs included, like connection fees, pipe laying, groundworks, etc.). So I can say that it is probably much more cost-effective.

@ €uro: Since when does photovoltaic generate electricity in overcast (but warm) weather? Or under cloudy skies? Or at night? Solar thermal systems can extract heat not only from the sun but also from the warm surroundings, like the air, which you can clearly see with the gas/solar setups next door. The gas burner doesn’t have to start when it’s warm and there is no sun. Just because photovoltaics are currently being criticized because of reduced feed-in tariffs doesn’t mean they are necessarily worthwhile overall. If there were an affordable way to store electricity (there are some options, but not affordable), that would be fine.

Besides, I personally don’t want any electromagnetic fields over my head in the bedroom (yes, I’ve already experienced this in an apartment where I used to rent and I have my reasons for this). Regarding fire safety, I’m not a fan of modules (no matter which type) on the roof. For firefighters, it’s often impossible to access a fire from outside if panels block the way, which can cost lives if fire suppression is needed from both inside and outside. I definitely don’t want to be crawling up on the roof to unscrew modules while the house is burning beneath me, not to mention that photovoltaic panels produce electricity regardless of whether you’re tampering with them or not, and I doubt a professional would want to go on the roof under those conditions.

Regarding electricity and gas prices, I’m confident—and so are you with Björn—that political reasons play a big role, which I’d be happy to explain if needed. These are things you only understand if you know how the strings are pulled behind the scenes 😉 I don’t want to say more (you never know who’s listening :-P). I can only say that it’s definitely possible to live without gas in a household; nobody is dependent on it. But nothing works without electricity (not even the circulation pump for a water-based fireplace).

Air source heat pumps are and have been, and probably will remain, a challenging topic because they require good, forward-looking usage behavior and careful planning. But for us, it couldn’t have worked out better...

Mörtelkännchen schrieb:
Sorry that my air-source heat pump is working so well; I guess I found an excellent heating installer for it, unlike the others 😉 The neighbors have the exact same house (the company I worked for built three identical houses side by side on separate plots, and I’m the only one with an air-source heat pump because I wanted it for my own use—I basically bought it from my then employer. The other two, for cost reasons and since they’re rental properties, have gas/solar systems (solar only for hot water), and we have significantly lower energy costs per year. We spent only 2000 euros more than the gas/solar setup (all included—connection fees, piping, earthworks, etc.). So I can say that it’s definitely more worthwhile.

@€uro: Since when does photovoltaic generate electricity in overcast (but warm) weather? Or under cloudy skies? Or at night? Solar thermal can extract heat not only from the sun but also from warm surroundings like the air, which is clearly seen in the gas/solar systems next door; the gas burner doesn’t have to run when it’s warm and there’s no sun. Just because photovoltaic systems are currently being sold off cheaply due to lower subsidies doesn’t mean they actually pay off in the end. If there was an affordable way to store electricity (there are options but not affordable), that would be fine. Also, personally, I don’t want an electromagnetic field over my head in the bedroom (yes, I’ve already experienced this in a rented apartment and have my reasons).

Regarding fire safety, I’m not enthusiastic about modules (of any kind) on the roof. For firefighters, accessing a fire from the outside becomes almost impossible, which can cost lives if they have to fight the fire from two sides (inside and outside). I don’t want to be crawling on the roof removing modules while the house is burning under me—not to mention that photovoltaic systems produce electricity whether I’m working on them or not, and I doubt a professional would go up on the roof under those conditions.

As for electricity/gas prices, I’m sure—and this is for you and Björn—that there are political reasons behind them, which I can explain if needed. But these are things you only know if you understand how the strings are pulled behind the scenes 😉 I don’t want to say more here (you never know who’s reading :-P). All I can say is it’s entirely possible to live without gas in a household; nobody depends on it. But nothing runs without electricity (not even the circulation pump for a water-based fireplace).

Air-source heat pumps are and have always been a challenging topic because they require proper, forward-looking usage patterns and good planning, but for us, it couldn’t have gone better...

Hello Mörtelkännchen, since when does a photovoltaic system generate an electromagnetic field at night—or do you just sleep during the day? I have the same east/west orientation and plan to install an air-source heat pump, photovoltaic panels, and a water-based wood stove. Heating is provided by underfloor heating via a buffer tank. If affordable storage solutions become available, I will largely disconnect from the energy supplier. For fire safety, smoke detectors will be installed, and if the house catches fire, it can be evacuated. Everything else will be covered by the building fire insurance anyway—or do you not have any?

Mörtelkännchen schrieb:
....@ €uro: Since when does photovoltaic generate electricity in hazy (but warm) weather? Or under a cloudy sky? Or at night? Solar thermal systems can extract heat not only from the sun but also from the warm surroundings like the air ...

How much is that compared to the state of charge of a comfortable storage tank (domestic hot water) ;-) Nothing! Have you ever looked into exact, real energy balances? Probably not! ;-)
HU: Which business owner would consider investing in a system that works well when there is no demand and hardly delivers when it really matters or is actually needed? They would be bankrupt in no time!
Of course, private builders are not business owners, which is why the sellers of solar thermal systems are doing so well, because the builders naively chase after various subsidies! ;-)

Mörtelkännchen schrieb:
...and this is clearly visible in the gas/solar combinations next door, where the gas burner doesn’t need to start when it’s warm and there is no sun.

Absolutely right, why should a gas burner operate when it’s warm? ;-) No heat production is needed here, regardless of the heat generator used.

Mörtelkännchen schrieb:
...Just because photovoltaic systems are currently being abandoned due to poor feed-in tariffs, that doesn’t mean they are not worthwhile overall.

One should shift from short-term views to annual balances to see this clearly!

Mörtelkännchen schrieb:
..., But nothing works without electricity (not even the circulation pump for a water-based fireplace)

Correct, that’s why I support photovoltaic and oppose solar thermal systems in detached houses!

Best regards

Mörtelkännchen schrieb:

Regarding electricity and gas prices, I am confident—and I say this for you along with Björn—that there are also political reasons behind them, which I can gladly explain if needed. These are things you only understand if you know how the strings are pulled behind the scenes 😉 I don’t want to say more (who knows who might be reading along :-P)

Share your insider knowledge with us 😉

All I can say is that it’s definitely possible to live without gas at home; no one is dependent on it. But nothing works without electricity (not even the circulation pump for a water-based fireplace).

I would agree with that for now. Short term, there would likely be problems with electricity if the 13% currently supplied by natural gas for generation suddenly disappeared. However, in the medium and long term, this could certainly be replaced.
But I have never doubted that.

What I do doubt is that an air-source heat pump still holds a significant cost advantage “TODAY.” In recent years, it was unquestionably cheaper than gas in many cases, but unfortunately electricity prices have risen much faster than gas prices recently. And due to the Renewable Energy Act surcharge and more homeowners upgrading their photovoltaic systems, I fear there will be another substantial price increase by the end of the year.

Hello,

DerBjoern schrieb:

I doubt that an air-source heat pump still has a significant cost advantage "TODAY." In recent years, it was undoubtedly cheaper than gas in many cases, but unfortunately, electricity prices have risen much faster than gas prices lately. And with the Renewable Energy Act surcharge and homeowners increasingly investing in photovoltaic systems, I fear there will be another major price increase by the end of the year.

In my opinion, your concerns are not unfounded. This is less about the increase in photovoltaic systems (and the reduction of subsidies) and more about new incentives for gas and a possible future increase in, for example, biogas plants.

Regards, Bauexperte