Which heating system for the 200 sqm new building?

Dear forum members,

I am new here and honestly have not yet read through all the previous forum posts, so a similar post might already be online.

We are a family with three small kids and are fortunate to be allowed to build in our hometown near Regensburg. We already built a small 145 sqm house in Tuscan style in 2011, but unfortunately it no longer fits our needs, so we will be building again now. We currently heat our home with a groundwater heat pump including cooling (which we rarely use). Overall, we are satisfied with the heating result, although on cold winter days I miss the cozy "warm feet feeling" that I know from acquaintances with pellet or gas heating. What bothers me more is that our hot water takes relatively long and only gets warm enough that I can still hold my hand under it.

We are considering a pellet heating system, but must admit that we have not dealt with the heating topic at all yet – and surely a lot has happened in the last 8 years. Our architect proposed a compact heat pump with central ventilation and hot water storage, as this would probably be cheaper than pellet with central ventilation. However, we definitely do not want an outdoor installation for the heat pump. An indoor installation would probably be possible, but we have concerns about the noise.

Is a central ventilation system necessary or even needed? At the moment we have a decentralized ventilation system, which works well, but the plastic covers inside, which have now yellowed, disturb me a lot.

What are your experiences? Ventilation – yes/no?
Heating – pellet, compact unit, or something else?

Thank you very much!
Best regards, Stefanie

Yes, there are quite a few threads on the topic here. What the architect says only makes sense in passive houses. Warm feet have nothing to do with the heating but with how poorly the house is insulated (the worse, the warmer). Gas or heat pump.

In modern houses, underfloor heating systems operate with low supply temperatures, so you won’t really feel much regardless of the system. Besides, I don’t think it’s healthy to be too warm from below. I find a central living space ventilation system very practical. We have grills made of stainless steel, so nothing discolors.

My favorite would be a brine heat pump with trench collector (some own effort) and BAFA funding. Slightly better than an air-water heat pump and not more expensive because of the subsidy. Additionally, as much photovoltaic as possible on the roof. That way you would have an economical, sustainable, and modern heating system. Through photovoltaic you produce your own electricity that (slightly) supports the heat pump and you even have some profit on top.

Plan underfloor heating well (flow temperature max 30°) and check the planning yourself.

Conceptually and structurally separate ventilation from heating and for the planning and selection of the heating system, it’s best to talk to someone other than your architect.

Ventilation is pure comfort and costs. In a single-family house, a central controlled residential ventilation system makes more sense than many decentralized devices. Please research yourself whether you want a ventilation system or not.

I would only install exotic heating systems like pellet heating if I have matching exotic reasons for it.

If the companies and planners for the heating system are either not good or too expensive or both, then a gas heating system makes sense instead of a heat pump because it tolerates planning errors better and is usually offered at a lower price.

My favorite would be a brine heat pump with a trench collector (some own work) and BAFA funding. Slightly better than an air-water heat pump and not more expensive due to the funding. Additionally, as much photovoltaic as possible on the roof. This way you would have an economical, sustainable, and modern heating system. Through photovoltaics, you produce your own electricity that (slightly) supports the heat pump and you even have some profit on top of that.

Plan underfloor heating well (supply temperature max 30°) and check the planning yourself.

Conceptually and structurally separate ventilation from heating, and for the planning and selection of the heating system, it's best to talk to someone other than your architect.

Ventilation is pure comfort and costs money. In a single-family house, a central controlled residential ventilation system makes more sense than many decentralized devices. Please research yourself whether you want a ventilation system or not.

I would only install exotic heating systems like pellet heating if I had matching exotic reasons for it.

If the companies and planners for the heating system are either not good or too expensive or both, then a gas heating system is an option instead of a heat pump because it tolerates planning errors better and is usually offered at a lower price.

Well, but your suggestion is more like the Mercedes among the solutions...
Just the cost of photovoltaics alone... and the own work on the trench collector I also find not trivial...

If gas had been available here, we would have chosen that; still the cheapest.

We have a heat pump with outdoor installation; inside I was worried about noise and outside honestly too. But it’s inverter-controlled and really mega quiet... you just must not take the cheapest split unit...

Definitely separate heating and ventilation. And I wouldn’t exchange our controlled residential ventilation system for anything anymore, best decision.

Well, but your suggestion is more like the Mercedes of solutions ... Just the costs of a photovoltaic system ....

Mercedes here probably means the costs. No, I see it quite differently. Photovoltaics not only financially pay for themselves through subsidies, but over time there is a profit of several thousand euros left. An investment is of course necessary, but currently, you will hardly find a better investment, even if financed by credit. Therefore, I cannot understand why the costs of photovoltaics deter many or are even a topic at all.

I myself overlooked it during construction and am only now getting my photovoltaic system installed on the roof. Large, expensive, and with guaranteed returns.

and the personal contribution for the trench collector is also not a piece of cake ....

Yes, that probably takes a day together with helpers. The bigger hurdle is likely the familiarization and planning of the topic. Due to subsidies, the whole thing is also not more expensive than an inexpensive air-to-water heat pump.

If, as a builder, you think about painting and plastering the house completely by yourself to save money – which quite a few do plan – then you save more money through this one day of personal contribution and can even go on vacation for a few weeks while the painter is working in the house. In that case, the argument of personal contribution does not apply either.

It will certainly be cheaper than the heating engineer’s offer if you plan and buy the heat pump yourself. It’s not rocket science either.

I myself also have only a compact air-to-water heat pump without an indoor unit. In fact, due to good planning, it runs so well in our case that a trench collector would only be insignificantly better. However, the technology is somewhat nicer, not more expensive, and with a trench collector you don’t need an outdoor unit, which was the topic here.