with / without central ventilation system experiences

Hello everyone,

We are planning our house construction (timber prefabricated house) and are currently considering whether to build with or without a central ventilation system and would be happy to hear about your experiences with it. Did you build with or without it and how satisfied are you with it in everyday life? Is the air in the house pleasant or perhaps too dry due to low humidity?

We promise/hope to have constantly fresh, unpolluted air in the house through such a system and to prevent mold growth in a tightly built new building. Because airing the house 2-3 times a day by opening windows will not happen in practice. Honestly, we already find cross-ventilating once a day annoying in everyday life. Occasionally opening a window when you feel like it is more realistic. (We currently live in an old building, where air exchange is not an issue)

On the other hand, the question is to what extent frequent airing is necessary at all with diffusion-open timber construction. Excess moisture is supposed to be adequately transported away anyway. And whether the produced moisture and CO2 are already well distributed across 160 sqm of living space.

Such a system is not exactly cheap and we do not know anyone in our family or circle of friends who has had mold in their apartment, even though windows are only opened occasionally and cross-ventilation is not constant.

It is hard to judge whether it is a great thing you will be very happy to have later or an expensive matter with little added value. Therefore, we would very much appreciate your experiences and tips on this :)

Best regards Sebastian

And whether the produced humidity and CO2 distribute well enough over 160 sqm of living space anyway.

Do you have doors in the house? I bought a CO2 meter to see how much I can reduce ventilation in winter without the air becoming too bad. With the door closed and reduced ventilation (not even minimum) the CO2 level exceeds the 1000 ppm limit within 1 - 2 hours.

Is the air in the house pleasant or maybe too dry due to low humidity?

You have to decide between musty, bad, and humid air in winter, or fresh but dry air. This can be counteracted with an enthalpy heat exchanger and producing moisture.

To be honest, we already find airing crosswise once a day annoying in everyday life.

That makes you predestined for controlled residential ventilation! It’s not only about mold. The effort of manual ventilation, CO2, other pollutants that off-gas from all sorts of things, pollen, noise... And you can also open windows with controlled residential ventilation. You just don’t have to ;)

We do not have a ventilation system and do not miss it either. In the morning, I go through the house once, open the shutters, and air out. Then again during the day and once more in the evening, at which point in some rooms the shutters are immediately closed again. Overall, little effort. Humidity after almost 5 months in the house is around 50%. No musty air. However, our room doors are almost never closed. And as long as the weather allows it, windows remain open to hear the birds, enjoy the fresh air, and experience the openness.

...

We are building a prefab house with timber frame construction, without a ventilation system or air conditioning. Initially, I would have preferred windows with window rebate ventilation, which we had in our previous old building, but our house manufacturer does not install those. After some thought, I think that is also good because I remember that this rebate ventilation was annoying when cleaning the windows and never got really clean.

If you find opening the windows in your house annoying, you have no other choice but to have a ventilation system installed.

My husband and I like to approach a window, look outside, open it, smell the air, and, as Motorradsilke already wrote, hear the sounds. In addition, we will, as in our old house, always have all doors open because we appreciate this openness. If we find that ventilating in the new house is "annoying" or unpleasant, we will retrofit some or all windows with window rebate ventilation. I have not dealt with the details yet, but it seems you can "clip" it on. There are various videos on the internet about this.

And, psst, this is really a secret now, ;-) because some people would surely scold me for it. ;-) I am thinking about, if necessary, simply removing a piece of insulating rubber from the window frame or poking openings in it. I am not even allowed to tell my husband, and I probably won’t do it. ;-)

But, as mentioned above, if you don’t like ventilating, the system is the only option. I only have concrete experience with offices and public spaces, and I don’t like the ventilation systems there, nor do I appreciate the air in those rooms.

Dear Hampshire, YPG, and Pagoni2020, please come back. You are really needed and missed here.

Never again without!
Air is always fresh. Less dust in the house and also very good for allergy sufferers as you can install a pollen filter…
Thanks to heat recovery, a controlled residential ventilation system is a zero-sum game with a great gain in comfort at the same time.
Everyone who doesn’t have a ventilation system and thinks their air is good should please set up a measuring device with a display.
Then you see that it’s just not the case.
Aside from the effort. Seriously, walking through the house every morning and raising all the roller shutters?
By that time, I’ve already had my coffee. The same thing in the evening, only backwards. New construction without electric roller shutters. Is that still a thing?

Hello, until now I never had a controlled residential ventilation system in any self-occupied property. Now I have been living in my passive house (super tight) since September 2021 with a central controlled residential ventilation system from Maico. Before that, I lived for 3 years as a transition in a newly built apartment with solid construction (stone on stone): 2.5 years out of the 3 I lived there it was damp, musty, simply bad! I couldn’t ventilate more because I am usually out of the house for more than 10 hours and in the evening, more than shock ventilation in winter with a slow underfloor heating is no fun. My old house was so drafty that I didn’t have to open windows (soon ..te) to ventilate. Energetically of course a disaster.

The air in the new house (without enthalpy exchanger) feels always good. I currently only display temperature and humidity with a simple instrument and the values are at 40-55% humidity. (Nevertheless, we are thinking about retrofitting the enthalpy exchanger which is possible with the system)

Due to a configuration error two days ago (I played a bit with the Air@Home app and forgot to save) I had turned off the system and the next day (yesterday) I wondered about the bad air. But we had already ordered filters because the old ones were dirty and thought that was the reason. Today I changed the filters and saw the system was not running. Turned it on and now everything is back to how it should be. Really never again without controlled residential ventilation. It’s like heated seats, distance cruise control or keyless entry. Once you have had the comfort, you will never want to go without it again (of course here too the exception proves the rule).