ᐅ Experiences with a Central Mechanical Ventilation System for Residential Buildings

Hello everyone,

So far, I have gathered detailed information from older posts in this forum about the necessity of a central ventilation system for living spaces. Especially in well-insulated houses up to passive houses, controlled ventilation is indispensable.

Despite this, I wonder how this complex duct system can be properly maintained over the years, and of course, at what cost? Obviously, the supply air from outside must be filtered, and this filter needs to be cleaned or replaced regularly. But what about the duct system itself? How does it get affected by dirt buildup?
I find the idea quite worrying: clean air is drawn in from outside, the filter is new, but then the duct system is dirty and full of germs. In the end, poor air is continuously distributed to all rooms. Or is it impossible for such a level of contamination to occur?

Best regards,
Earl