Ventilation system in the new building, yes or no?

I’ll join in here. We have received the first drafts for our planned single-family house. Energetically, it is supposed to be a KfW70 house. Air heat pump indoor installation, underfloor heating, 36.5 Poroton T10 without additional external insulation.

As I read here and my house builder also confirmed, a HWL is not absolutely necessary, only for KfW55 and passive houses. However, it definitely brings a significant comfort gain. In the energy saving portal, I heard of costs for our house size of 140 sqm including basement of 3-5 thousand euros, here it’s already reaching five-figure amounts. What do you think? Useful accessories? I mean, a lot can be retrofitted afterwards, but something like this is rather difficult/expensive.

How does it look with hygiene? What if mold forms somewhere in the pipelines or bad air comes through? How high are the maintenance costs and how often does such a system have to be maintained? It’s not only the acquisition costs but also the ongoing costs that matter in decision-making.

Hello,

I can read all kinds of things in the long post, especially a lot of polemics. But not your opinion on why the ventilation system would now be indispensable. What a pity...

It always depends on the point of view (professional profile) of the observer

As long as a house is built _without_ ETICS - exactly in the area of Kfw 85 or 55 (beyond that, at least a 3-layer masonry (e.g. 2 x aerated concrete masonry with appropriate insulation in between = 10 +, at least in solid construction) must be offered - any builder can _without_ disadvantages do without the installation of an air-to-air heat pump - controlled ventilation is nothing else; because mold can only develop where the exterior wall does not allow diffusion. With construction costs in the range of EUR 3,000 to infinity (depending on the house size) you can calculate yourself when the amortization starts - regardless of the benefit of the system

Best regards

Hello,

....about the installation of an air-to-air heat pump - Nothing else is controlled ventilation - ...

Well, I would think about that again. regards

Hello,

Well, I would think about that again

I am confident that you will explain yourself in more detail.

Kind regards

Well.. an air-to-air heat pump is the same as an air-to-water heat pump.. only with the difference that the heat transfer medium is not water (e.g. underfloor heating), but as the name suggests, "air".
This may make sense for a passive house with minimal demand.. coupled with a ground register.. but that has nothing to do with a [Kontrollierte-Wohnraumlüftung].
The air-to-air heat pump is a heating system... the [Kontrollierte-Wohnraumlüftung] ventilates.. and sensibly with heat recovery and the possibility of humidification.

Well.. an air-to-air heat pump is the same as an air-to-water heat pump.. only with the difference,..

If something is the same, there can be no difference!

...I am confident that you will explain yourself further.

Yes, as BauLine writes: A controlled residential ventilation ventilates and a heat pump heats or cools!

Best regards