Controlled residential ventilation with heat recovery --- a confusing maze?

Hello dear forum friends,

we are - more or less - at the selection of the general contractor and now the question arises about the installation of a controlled residential ventilation system with heat recovery, which we had actually already decided against for ourselves.

An appointment with a building expert from the Homeowners' Protection Association thoroughly shook up my views once again and raised the question of the "whether" again.

Just to preempt any possible (forum-typical) accusations: yes, I have now absorbed information like crazy for one and a half days in this forum and elsewhere. I am probably wiser, but somehow still not ready to decide. It can't be that I have to roll dice or flip a coin here.

I would really be interested in concrete arguments why one might possibly do without such a system. For a controlled residential ventilation system with heat recovery (Pedotherm / Vaillant) we would have to pay almost EUR 10,000. That is of course a chunk. The general contractor did not push here but clearly said that it is not absolutely necessary (if you really ventilate well). Now, in our case, between about 7 a.m. and 4 p.m. practically no one is at home. That would (new building) be rather unfavorable in the first years, because (shock) ventilation would of course be missing here.

man man man, it’s quite annoying when you are this uncertain. Can you contribute to the certainty?

Good morning,

Just to prevent any (forum-typical) accusations: yes, I have now spent a day and a half in this forum and, like a madman, absorbed information everywhere else as well. I am probably wiser now, but somehow still not ready to make a decision. It can’t be that I have to roll dice or flip a coin here.

Preventing didn’t help


No one can make this decision for you, just as no one can ultimately argue for or against a controlled residential ventilation system with heat recovery. In this respect, your gut feeling and your budget are required, as it is above all a very personal decision. By the way, Bauherren-Schutzbund – what the ladies and gentlemen working independently under this umbrella sometimes say should always be taken with reservations. Quite a few of them overshoot the mark, others don’t find it at all, nor do they know the way.

The general contractor did not pressure here but clearly said that it is not absolutely necessary (if one really ventilates well). Now, in our case, however, practically no one is at home between about 7 a.m. and 4 p.m. That would (new build) be rather unfavorable in the first years, since (shock) ventilation would of course fail here.

From my professional point of view, a reasonable statement, since houses are becoming (or have to become) increasingly airtight. In solid construction without ETICS "it can" work without ventilation, but it doesn’t necessarily have to; in a new building with ETICS this question, in my opinion, does not even arise. The exciting question here can also be whether it "must" actually be a controlled ventilation or whether a decentralized system "could" also be an option (attention ... now there will be controversial discussions again) – so the compromise between profession and ventilation can be met in the middle. Especially since the decentralized systems also have some advantages and require roughly half the investment.

Man man man, it’s quite annoying when you are so unsure. Can you contribute to certainty?

No

Rhineland greetings

We are going with a massive build and a brick facade, so without ETICS. This way, our house still "breathes" a bit, which was important to us. Additionally, for budget reasons, we decided against a controlled residential ventilation system, even though we are also not home during the day (at least for another year). We believe reasonable shock ventilation in the morning and evening will be sufficient. No one can make this decision for you.

The decision is one you must make entirely on your own. We are building massively without [WDVS (36.5 Poroton)] and without controlled residential ventilation. However, we have decided on decentralized ventilation with humidity control in the bathrooms and the utility room. These 3 ventilations cost us around 1000 euros.

We are still thinking about a decentralized system. : Why in the utility room? Is washing done there? I am wondering where else we would need a decentralized system.

Yes, we have separate utility room and technical room. The washing machine and dryer will also be located in the utility room, as well as occasionally the drying rack. Therefore, we have installed a decentralized system everywhere there is more moisture (or are still doing so).