ᐅ Types of Heating Systems: Underfloor Heating, Gas, Air Source Heat Pump? Any Experiences?

Hello everyone,

My boyfriend and I are about to start detailed planning for a new single-family house in the Berlin/Brandenburg area. We have already had a few discussions with different construction companies just to gather some initial experience. In many areas, we feel more confident now, but we are completely uncertain when it comes to the heating system.

It feels like every company tells us something different. Just when we think we have made up our minds, the next conversation tells us that is totally wrong.

That’s why I wanted to ask the more experienced members here for advice, since I didn’t find clearer answers in other forum posts.

The house will be one and a half stories with about 140sqm (1,507 sq ft) and a basement. We want to build to KfW 70 standard to qualify for subsidies. We do not want geothermal energy. There definitely will be underfloor heating. Currently, we are just two people. Eventually, we plan to have two children...

What we have been told so far: underfloor heating combined with a gas boiler is not sensible... underfloor heating with an air-source heat pump, on the other hand, is very sensible... why? I can't remember... probably because it would offer a better energy balance... A ventilation system with heat recovery combined with underfloor heating is also said to be not good. It supposedly causes drafts, you might easily get sick, and that wouldn’t be ideal...

We are very uncertain. Ideally, we would just go with underfloor heating and gas without much extra hassle. But apparently that is considered a bad choice... So what is correct? Can you help?

Lisa86 schrieb:
Ventilation system with heat recovery and underfloor heating is also not good. There’s a constant draft, you can easily get sick

Now that you mention it, I know why I’m always sick 🙂

Seriously though, I even have geothermal heating. Am I supposed to drop dead now? I’ve rarely read or heard such nonsense. As long as the system is properly designed, you can do whatever you want. Some salespeople either don’t know what they’re talking about or just prefer one system. Maybe they earn more from it, who knows.

Hello,

here are some possible reasons for the confusing answers:

Lisa86 schrieb:

What we have been told so far: underfloor heating and gas boiler is not practical

It takes quite a bit of expertise to achieve KfW 70 standard using only gas. Also, an air-to-water heat pump sells better – everyone wants one (although not everyone knows if it really makes sense for them).

Lisa86 schrieb:

...underfloor heating with air heat pump on the other hand is very practical... why? I don’t remember anymore

Because for the in-house structural engineer it is the easiest to calculate and the simplest way to reach KfW 70; at least on paper.

Lisa86 schrieb:

Ventilation system with heat recovery and underfloor heating is also not good. It constantly drafts, you can easily get sick and that wouldn’t really be ideal...

A good ventilation system is very expensive, and most consultants cannot convincingly explain its benefits. There may certainly be reasons against a central system; however, if planned and installed correctly, the issues mentioned above should not occur.

Lisa86 schrieb:

We are totally confused. Actually, we would just like underfloor heating and gas, without much fuss. But that is supposed to be a bad idea... so what is true? Can you help?

Then stick with that and don’t let anyone talk you out of it – whether you need a ventilation system has to be calculated by the structural engineer. In many cases, a decentralized system and additional insulation are sufficient – especially if you didn’t buy a site facing strictly north.

I can only emphasize again – even if you are a complete layperson, your gut feeling will protect you from a lot … if you listen to it 😀

Regards, Bauexperte

@ perlemann: I also didn’t find the explanation very convincing… I just can’t imagine there being drafts inside the house… otherwise, no one would build like that. I understood the main benefit to be that you lose less heat through ventilation, which means lower heating costs… regardless of where the heating energy comes from. That’s why I find this concept generally very interesting, since it also provides a good indoor climate, right?

@ Bauexperte: I will definitely trust my gut on this. It all feels too uncertain to me. How am I supposed to know what new technology will be available in 10 years that might replace the old gas boiler? Maybe it will turn out that maintenance or repairs for all the pumps will be very expensive, making the advantage disappear altogether. For now, the gas boiler is my priority, along with underfloor heating and insulating the house to meet KfW 70 standards. We are still considering the ventilation system.

We don’t have underfloor heating, but we are very satisfied with the combination of the gas boiler and the ventilation system.

You can have endless debates about which heating system is the best. We chose the most affordable option for a KFW 55 house. In our opinion, an expensive heating system doesn’t make sense when the heating demand is very low.

We didn’t want geothermal energy, and a split outdoor unit was also not an option, which already narrows the choices significantly. And definitely not radiators, as we preferred.

We also followed our intuition. We now have underfloor heating powered by gas, which will be installed throughout the house. The drilling for geothermal energy costs quite a bit, and we didn’t want to rely on ground heat. We also didn’t want an unsightly system in the front yard that constantly releases water and freezes.

The only thing that convinced us was the controlled ventilation system with heat recovery. Since modern houses are airtight, they need constant ventilation to prevent mold. We cannot manage that ourselves during work hours. We also don’t want to become daily slaves to the house.

Therefore, we opted for a solid gas plus solar setup, additional insulation, and the controlled ventilation system, meeting KfW 70 standards 🙂