ᐅ New construction with Poroton T7 MW 36.5 blocks without a mechanical ventilation system

Not having to ventilate goes even beyond the supposed ventilation efforts... both in winter and summer, I prefer to keep the windows closed because there is a reason I invested 300,000 Euros in a house: to keep the weather outside.
If I didn’t care, I would have moved into a tent – at least there it is dry.

You can look at it any way you want, but plastic bags or yogurt cups, like houses built nowadays, require air exchange.

And this can only be achieved if someone works from home or if someone is present during the day... if it is purely a "sleeping house," then nothing works without a controlled mechanical ventilation system, at least not in the city.

Because here, I cannot simply leave the windows slightly open in summer or winter. Otherwise, I risk coming home to find the house unwillingly "cleaned out" by some unwanted visitors.

If you are not familiar with a house equipped with controlled mechanical ventilation, you don’t miss it. However, my wife and I clearly notice the difference when we visit friends or neighbors without one.

I also find it hard to believe that mold could form inside the ducts... it’s not a breeding chamber. There simply isn’t any nutrient supply. I once posted pictures somewhere here showing what a system looks like after three years of continuous operation.

Exhaust air duct: light layer of dust
Supply air duct: looks like newly installed
Fans: light layer of dust
Heat exchanger: looks new

The systems are generally only audible at full capacity.

I also cannot understand where they say space is lacking for these systems. All my ductwork is suspended from the ceiling in the utility room. The unit itself is mounted on a wall just below the ceiling (with enough space underneath for a washing machine), and the ducting runs through the house under the raised floor beneath the underfloor heating insulation... so I have no loss of usable space. Everything was installed exactly where unused space was already available.

And the 50 euros (around $55) per year for electricity and 10 euros (around $11) for filters really don’t make me poor... but in return, there is always clean air in the house.

Mycraft schrieb:
No matter how you look at it, plastic bags or yogurt cups—houses built like that these days—require air exchange.

However, I find this term a bit misleading. An ETICS (external thermal insulation composite system) is not airtight. The airtight layer is the interior plaster. A Poroton T7 house is just as airtight as a sand-lime brick house with 30cm (12 inches) ETICS. The term "plastic bag" suggests that it’s about the ETICS, but that’s not the case at all.

If you only had a vapor barrier on the top and the house was open on all other sides, it wouldn’t be airtight. The goal is for the entire house to be airtight. This airtightness on the sides is achieved through the interior plaster, so there is no difference whether you use calcium silicate blocks with external thermal insulation composite system (ETICS) or brick.

I only mentioned that the term "plastic bag" can create false associations. Some might think we are building without ETICS, meaning no “plastic bag.” The “plastic bag effect” is actually achieved by the non-plastic components of the exterior wall.