Proper Ventilation and Dehumidification

Our construction started in autumn and has progressed well. Screed is installed, interior plaster and exterior plaster are finished. Since yesterday, the screed has been heated with a mobile heating device connected to the underfloor heating. The moisture in the house is correspondingly high. Windows are fogged up, all external corners are damp. We hear different suggestions on how to properly handle the moisture from various sources.

- Construction company: "Dehumidifiers/construction dryers are not necessary, just ventilate by opening windows fully three times a day, do not keep windows tilted open permanently"
- Painter: "Simply keep a window tilted open on each floor during the day, then there will be good airflow."
- Sanitary/heating company: "In winter, ventilate fully at most twice and maybe set up dehumidifiers"
- Engineer friend: "Set up heating devices and two high-end construction dryers and tilt open a few windows."

Currently, we do the following: Depending on how we need to work, we ventilate fully two to three times a day. On each floor (basement, ground floor, upper floor) we have set up a dehumidifier, which according to the manufacturer is sufficient for rooms up to 72m2, and we let these dryers run during the day. At night we turn them off, partly so that electricity costs do not become too high and we do not want to leave the devices unattended for 12 hours. These devices can also be used later to improve indoor climate and for drying laundry.

Do you have any further recommendations or corrections?

Instead of a dehumidifier, use a construction dryer. You rent it for 14 days and let it run 24 hours a day. Electricity costs are irrelevant because it has to be done and are also factored into the ancillary construction costs. Dehumidifiers somehow don't really do anything except remove moisture from the air. Construction dryers pull the moisture out of the walls. By the way, one per floor is enough ;) Avoid tilt ventilation, prefer shock ventilation.

Ok great thanks. We will speak with the construction company again to see if they can provide something. I think that would be better :)

You borrow it from a hardware store. If the construction company has something like that, that's good, but why should they?!

The only thing you can really do wrong is tilting the windows - so much for the painter and the "engineer". Dryers or shock ventilation, depending on how much time you have, both are okay.

Super thanks for the feedback, that already helps!