Gas heating + solar & controlled residential ventilation or air-water heat pump Energy Saving Ordinance 2016

Then just do it the way I did now. I have scheduled an appointment next week at a local energy agency of the district. Yes, such things do exist, and it’s all non-binding, free of charge, and you have a competent and neutral energy consultant who can certainly answer such questions.

Because getting thousands of opinions and preferences in the forum and reading everything meticulously didn’t get me any further at all, especially since no one has even remotely said which offer would be the more sensible one!

However, the facts I can definitely tell you are:

- In recent years, electricity prices have continued to rise, while gas prices have stayed almost at the same level; whether that will ever change, no one knows, especially not here in Germany!

- The annual performance factor of the air-to-water heat pump depends heavily on the weather, and no one knows how the next 5/10/15 winters will be. Moreover, the actual annual performance factor of the air-to-water heat pump is on average "about" 3, but most are advertised with COP values of 3.4-3.6. It’s just like with cars, all laboratory values.

- But, thanks to the mighty beautiful (irony) Energy Saving Ordinance 2016 regulation, the gas heating system doesn’t only have to be combined with solar thermal, no, if you want to build solidly, it must also have a ventilation system with heat recovery. Therefore, an air-to-water heat pump with underfloor heating is just as expensive if not already cheaper than the gas heating system with all the extras.

These are my thoughts at the moment, let’s see what comes out after the consultation next week.

I agree with you on everything, I also had individual advice. Individual here means especially in relation to my property, my soil conditions, and my floor plan. In the forum, one quickly runs the risk of simply ignoring certain framework conditions. For example, we also considered gas versus air-water heat pump/ground-water heat pump. Some in the forum get the drillings at a very low price, manage with just one drill hole, and possibly have well-regenerable soil. For us, you can only go down 40m, so that means about 4 to 6 drillings, totaling 15k just for the drillings. Then the soil is quite clayey, meaning limited regenerative capacity must be expected. The problem here in NBG is that 2 to 3 people have the issue that the probe extracts too much energy from the soil, meaning the precipitation is not enough to supply energy back to the soil. Highly impervious soil does not improve the situation either. So, the COP goes down. Then gas vs. air-water heat pump. The gas connection was already paid for with the property, so it would be attractive. Nevertheless, it does not really pay off because the replacement measures (more insulation, even better windows) would be nonsensical and expensive. Photovoltaics are still too expensive and on a shed roof with a 7-degree pitch, an aesthetic complete disaster or compromises in efficiency. In addition, the exhaust gas routing must be considered for gas. Our technical room is in the basement (southeast) and the chimney in the living room (west) is some distance away. Therefore, the exhaust gas routing does not work via the existing chimney – it would only partly work so. So, another "chimney" would be needed, which is not possible from a floor plan perspective or only with major restrictions. That leaves air-water heat pump, with outdoor installation, unfortunately in the front yard. Indoor installation does not work due to clay soil, accumulating seepage water, and corner installation is not possible because the sun deck is adjacent on the south side. This can simply not be sealed well enough. What I want to say: here the "tax declaration on a beer mat" is quickly done and "calculated" that xyz is much cheaper (especially often the case with gas). That may even be true for one or the other, but in my opinion the individual conditions have too much influence for general statements to make any sense. At least that is my "insight" [emoji6]

My thoughts on gas prices/temperatures. Gas means dependence on the Russian tsar, which I certainly don't want, but this is more of an emotional topic, less numerical. Yes, the air-water heat pump is an electric heater, true. As bad as that is for the global climate, the winters tend to be warmer here, so the use of the heating element should tend to decrease. At least I like to tell myself that [emoji6] The biggest risk still lies with the installer, the economics rise and fall with that. We try to reduce the risk by having the installation/detailed design done by HLB, the rough design and acceptance by the manufacturer. But a residual risk remains...

As stupid as that is for the global climate, the winters here tend to be warmer, so the use of the heating element should tend to decrease. At least, that's how I convince myself.

The heating element actually plays no role in reality. The great fear of it is quite unfounded. For us, it was only activated at temperatures below -10 degrees and was only active for a few hours. At such temperatures, the difference with/without it is not that significant anyway. But how often do such temperatures really occur? This winter, with at least 6 such nights, was colder than usual for us.

What I want to say: here the “tax return on a beer coaster” is quickly done and “calculated” that xyz is so much cheaper (especially often the case with gas). That may even be true for some, but in my opinion the individual circumstances have too much influence for general statements to make any sense.

In a few years, you will get nice houses cheaply, which only lie around like lead on the shelf because a technically still young and flawless heating-climate system would have to be thrown out for economic reasons – simply because the gap between theory and practice in the wallet is then too painfully real. My motto in such matters is “when in doubt, go against flashy new junk.”
On paper, every new technology always initially flies to the moon, and in reality, it is sometimes just a Berlin airport.

Heat pump consumption database.... Real values, not calculated. It doesn't get more objective than this. Publicly accessible, anyone can take a look.

Heat pump technology has existed for many decades, it has nothing to do with new technology. Will many current cars also soon become unsellable because new technology is always being installed? Hardly.

Can only agree: it always depends on the individual framework conditions. If you can get a ground collector cheaply, geothermal energy is usually unbeatable. If the gas connection is already included in the price... gas is unbeatable..., etc.

haha exactly, houses like lead because of out-of-control heat pumps. And then something about Berlin airport. Whoever wants to understand that, 11ant has put the turbo on again today.