Pros and Cons of Ventilation and Exhaust Systems

Yes, I keep reading everywhere... two statements:

1. No, I can also open windows! - From those who don't know the systems and have never experienced them

2. Never again without! - From those who know ventilation systems or have taken the step and had one installed.

As you can see, usually people are against it without experiencing it themselves... once they've experienced it, they don't want to miss it...

As my predecessors said, the noise level strongly depends on what kind of system/location of installation/air circulation volume, etc. My system is in the utility room and you can barely hear it from "far back" starting at 200 cbm, but much quieter... at night the system runs at 50 cbm... then you can't hear anything... on the "party function," meaning full blast, you can hear the system at about laptop volume... but the system only runs at full blast rarely... and if you have a party then you don't notice it anymore...

When you open windows, environmental noises also come in...

I listed it as a disadvantage, but only for completeness... every range hood is many times louder even at the lowest setting...

Ok, so there are advantages. Although, sorry for saying this, I am still in favor of throwing open the windows. I also sleep with the window open – even in winter. How loud is the system? Does it hum constantly? As loud as a notebook, for example, or rather quieter?

I don’t know who wouldn’t have open windows at decent temperatures. Open windows in winter: invested in a great/expensive future-oriented heating system... energy costs skyrocket... and then you waste energy at night – that is what you want to avoid with a controlled residential ventilation system. Besides, as mentioned above: our houses nowadays are absolutely airtight like a plastic bag. We humans produce moisture: through showering, cooking, and sweating at night. That then eventually causes mold in combination with heating air. Your evening ventilation in your living spaces is not enough to carry out the moisture. There need to be more intervals during the day... I once read about 6 to 7 ventilation intervals. Who can manage that???? Right: the controlled residential ventilation system.

So we keep the windows closed whenever possible. In summer to keep the heat out. And at night to keep out the millions of flies and mosquitoes (the lovely rural life on the Rhine). In winter, to avoid blowing the expensive heated air outside. The only exception: When the fireplace is on, I open a window slightly... Otherwise, it gets too warm. Our ventilation system always runs on level 1, 50cbm. Only when guests are here, a lot of baking has been done, or it simply gets too warm. What is actually a myth, at least in my observation, is that the controlled residential ventilation heats the other rooms when the fireplace is burning. I checked in spring once... Outside temperature -5°C, fireplace running full blast, supply air temperature in the system 15 degrees. But the rooms upstairs had a room temperature of 18 degrees... this is not how heating works. And if it does, the effect is minimal... what helps more: opening the living room door and using a small fan to blow the warm air out. (Our fireplace is right next to the door.)

our ventilation system always runs on level 1, 50cbm. Only when guests are here, a lot of baking has been done, or it simply gets too warm.

That seems a bit low to me? You also have around 130-140sqm, right? We need 120cbm at level 1 for that. Then unfortunately you can hear the ventilation system as well.
We can't get the dry air under control here - humidifiers, wet cloths - all attempts end at max. 40 percent. Does anyone have any tips? We have an evaporator humidifier (allegedly designed for 40sqm).

That seems a bit low to me? You also have around 130-140 sqm, right? We need 120 cubic meters at level 1 for that. Then unfortunately you can also hear the ventilation system. We can't get the dry air under control here - humidifiers, wet cloths - all attempts end at a maximum of 40 percent. Does anyone have any tips? We have an evaporator humidifier (allegedly designed for 40 sqm).

You may be right. I just looked in the manual, but I just noticed that more than 3 levels are described there.... I think my 3 levels are probably somehow configured/calibrated. So I can't specify the current airflow. I would have to look into the log. Regarding humidity.... plants with large leaves help... But what's so wrong with 40%? In winter that's actually normal...

Your evening ventilation in your living spaces is not enough to carry out the moisture. There need to be more intervals during the day... I once read about 6 to 7 ventilation intervals.

Wow! Is that true? Then all new houses without controlled residential ventilation would have to mold, because who ventilates 6-7 times a day?

What I also don’t understand, the ventilation system is supposed to carry out the moisture but many people write here that the moisture in the rooms increases and that this is even desired. The next person (see above) has rooms that are too dry with controlled residential ventilation. So how is it now – does it get drier or more humid? Did I misunderstand something?