Achieving good indoor climate values

Hello

Who among you, like us, will soon be building a house that has very good or high values regarding window insulation and also facade insulation (so a very tight building envelope).

Now we have read that houses that are too well insulated tend to have rather low air exchange because hardly any natural air circulation takes place. In Minergie-certified buildings, this problem is supposed to be solved with a controlled residential ventilation system. However, such a system is not planned as standard for us and we actually wanted to forego it for cost reasons and other considerations!

Since we are both employed, the windows will probably remain completely closed for long periods during the day. My question now: do we have to risk permanently having poor air quality and an unpleasant indoor climate or even moisture problems (wet windows in winter) in our own home?

Does anyone among you have concrete experience with this or is an "expert"?

hi pat

In your report, I cannot tell whether you are building massively or with wood. I have a wooden house. That is actually not a problem, because the air is exchanged through the walls. Or rather, wood breaks down toxic substances and renews the used air. You don't live there like in a plastic bag :) The moisture actually goes somewhat through the walls – so it can't really become decisively too humid. I have been living here in my house for over 5 years and am still completely enthusiastic about the living climate!

regards

hello So it is solid construction - bricks of course. Exterior thermal insulation 160mm (actually already Minergie standard). regards

Hello everyone The ventilation losses of every house should be around one third or more. What does that tell us? - That corresponding energy must then come into the house! Anyone can then calculate how much energy is actually blown out the window. It is indeed the case that especially in tight and very tight houses, sufficient air exchange must be ensured. Otherwise, moisture can potentially lead to mold formation, for example on walls! The indoor climate then is also no longer particularly pleasant... We have a controlled residential ventilation system and would never want to do without it! Although we have a wooden house where the whole "construction" is diffusion-capable. Because wood can absorb a lot of moisture. And as already mentioned, wood has a cleaning effect. Toxins in the air are broken down by wood (not stored). Wood lives...! @Patrik According to your information, the insulation of your house is in the Minergie range. With only 16 cm, however, it is quite tight. Still, I wonder why not Minergie from the start? That step would have only been a small one. In 4-5 years, it will be prescribed anyway. No one will be able to avoid Minergie then! In addition, a Minergie house also has a higher resale value - ok, who wants to sell their newly built house again :) - but it has all happened before... Best regards

Thank you for your assessment.
Your prediction that Minergie houses will be mandatory in about 4-5 years is quite a claim... but of course you're right that energy-efficient houses will probably soon have a market advantage. However, I believe one shouldn't be too trusting of labels. I know the Minergie criteria quite well, and I find that they only partially say something about the energy or ecological balance, since a Minergie-certified house can indeed have an oil heating system or many inefficient electrical consumers and no one cares about that. In other words: I think our house is certainly energy-efficient and ecologically built. But without this ventilation, you simply won't get the label. Besides, the question arises whether the ventilation ducts can/need to actually be integrated into the concrete ceiling. Because that would be the only possibility; otherwise, we would have to sacrifice about 8cm of room height, and of course we don't want that (with 2.40m).

Regards and thanks

First of all,

We also don't have ventilation because we don't want such a system! But the idea that with a comfort or mechanical ventilation system you should/must/can't open the windows is a misconception, because it is simply not necessary!

We are also building a wooden house for ourselves, which is therefore also diffusion-permeable. That's why I think ventilating twice a day by briefly opening the windows is enough, which we are already doing... (rental apartment)