Pros and Cons of Ventilation and Exhaust Systems

Hello, I think such a system is not absolutely necessary or let’s say better, the enormous advantages have not yet become apparent to me. I prefer to open the window. What speaks in favor of the ventilation system and what possibly against it?

Hello,

I had a similar problem at the beginning of our construction orientation phase. Especially in the summer, our apartment is usually open in the evenings when we are at home, which provides sufficient ventilation.

In winter, however, we regularly struggle with condensation because, for example, we cannot open our skylights when there is snow on the roof or rain and wind from the "wrong" direction.

Furthermore, our current apartment is 11 years old, so it is no longer comparable to today's insulation standards, which in our new building should lead to even more condensation in the cold season if not ventilated sufficiently.

Therefore, I was convinced to install a central ventilation system with heat recovery.

This system will also remove construction moisture from the house without much ventilation effort, and as an additional bonus, the system will distribute the heat from our wood stove throughout the entire house thanks to the heat recovery.

I still do not find the system absolutely necessary – for me, it is more a "nice to have"...

Regards,

Dirk

You are now going to start a religious war with this

Sure, you don’t need a ventilation system. BUT you should keep in mind that the likelihood of mold increases significantly if you don’t ventilate consistently.

Our house is extremely airtight, if you put it harshly, we live in a plastic bag. If I turn off the system, which often happens overnight in winter, and I forget to turn it back on, it gets extremely stuffy, at least for me. In spring, shortly after moving in, this happened to us more often. Then the whole house smelled like the diaper bin and whatever was cooked the night before. The new furniture was still off-gassing, and it was all not so great. If the system ran through the night, it had the disadvantage that the room temperature dropped overnight... from 19 to 17 degrees, but the air was clear.

Additionally, I could show you pictures, if I had any, of the exhaust filters that I change every 2-3 months (2 € each, total of 5 pieces per change).

The ventilation system has the advantage that I do not HAVE to ventilate, but I still can. Shortly after dinner, I have fresh air in the house again, and the mirrors don’t fog up. Another advantage that we often use: When many guests are in the house, our living room tends to heat up to 25 degrees, which makes it too warm for most guests. The ventilation system lowers the temperature by 1-2 degrees. You could tilt windows, but here in the countryside it has the disadvantage: with the air come moths, flies, mosquitoes, and whatever else likes to fly into the "light". Another advantage: pollen filter. My wife really appreciates this. Our consumption of antihistamines has dropped sharply.

Disadvantages still need to be named. About 50-100 € / year electricity costs, 50 € replacement filters, 50 € filter in the device itself, cleaning the filters, and in summer at night, when on level 3, you can hear the system... but you gladly accept that if it cools down by 1-2 degrees, and the high costs of acquisition...

But one of the probably greatest advantages is A the heat recovery and the regulation of humidity upwards. In winter, we had a humidity of 20% in the living area; after installing the enthalpy exchanger, this rose to about 35%. Not perfect yet, but I’m sure we’ll have plants someday, then it will get a little better.

Conclusion: I would never want to build without it, especially not after ours has been running.

The nice thing about a controlled residential ventilation system is that you can still open the windows if you want to, and when the windows are closed, the moisture also comes out and you always have fresh air in the house.

Pros:

- No excessive moisture in the house all year round
- Always fresh air at home, even when you come back from vacation
- Less heat loss in winter
- Better heat distribution in winter
- Better temperature distribution in summer
- No mold anywhere, not even behind any furniture
- Less dust in the air
- Very good for allergy sufferers, as pollen stays outside
- Quickly drying laundry on the line and also towels in the bathroom, e.g., in winter inside the building
- Bathroom/shower humidity out within minutes

Cons:

- Acquisition costs
- Operating costs (between 20W and ~200W power consumption)
- Maintenance costs (filters + rough cleaning every 6 months + complete cleaning every 10 years)
- Appearance (if disturbing), i.e., valves in ceilings/floors/walls/facades
- Noise level
- Dry air in winter

The values I have given are of course only estimated, as every manufacturer has something different, but all more or less in the same range, since the systems are all based on the same principle.

Disadvantages: - Noise level

Ok, so there are advantages after all. Although, sorry for saying this, I still prefer to throw the window wide open. I also sleep with the window open – even in winter. How loud is the system? Does it constantly hum? As loud as a notebook, for example, or rather quieter?

Ok, so there are advantages. Although, sorry for saying this, I’m still in favor of throwing the window wide open. 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?

So, in the utility room it can be heard well, and outside you can hear it too. So if you sleep right above the technical room and have the windows open, you will hear it... although you can turn it off at night. During the day, our system is not audible at all in the living areas. No matter the setting. Only in the room directly above the utility room can you hear the system. However, only at level 3; at level 2 it is almost inaudible. In general, it also depends heavily on the installed system and how well it was calibrated and installed. I think that in this one room, the sound damper used was either forgotten or installed incorrectly. But we will have it checked again. So far we only use the room as a guest room, so we haven’t noticed it until now. You should not imagine such a system like a kitchen extractor hood... much less is sucked in and blown out. If you put your ear directly to the ventilation grille, you can hear it. Maybe also if you focus strongly on the sound. But I hardly think about the system... and I’d say... the 5 wind turbines 3 km away and the highway 5 km away can be heard more, with the window open.