Dear forum,
My name is Markus, and we have just moved into a condominium in Dresden [built in 2016]. My question relates to this...
The apartment has a decentralized ventilation system from the company Lunos; specifically, the e² model with heat recovery. Aside from the fact that I find the fans extremely noisy, they also don’t seem to achieve their purpose. Take our bedroom, for example: 12 square meters (129 square feet). One fan is installed. This morning, after airing out the room by opening the windows, the humidity level was 55.6%. My wife worked in this room for 3 hours. Meanwhile, the humidity increased to 64%, despite the ventilation running on the highest setting.
The system’s filter is clean, so that can’t be the problem. The fan itself works; there is airflow. But this can’t be what the system was designed for: First, the fans on the highest setting are difficult to use because they are too loud at 50 decibels. And then even this highest setting can’t maintain the current humidity level? I don’t understand. In my opinion, these fans are completely ineffective.
Since our building is very well insulated, I actually have to air out the room by opening windows three times a day, otherwise the humidity quickly approaches 70%. Three times a day! This is really annoying and should not be necessary with a decentralized ventilation system.
Am I missing something here? Is this the case with all ventilation systems?
I would greatly appreciate any input. On one hand, because I would like to find a solution [different fans?]. On the other hand, because I find the situation so unbelievable. It can’t be that these "things" have no effect...
Best regards,
Markus
My name is Markus, and we have just moved into a condominium in Dresden [built in 2016]. My question relates to this...
The apartment has a decentralized ventilation system from the company Lunos; specifically, the e² model with heat recovery. Aside from the fact that I find the fans extremely noisy, they also don’t seem to achieve their purpose. Take our bedroom, for example: 12 square meters (129 square feet). One fan is installed. This morning, after airing out the room by opening the windows, the humidity level was 55.6%. My wife worked in this room for 3 hours. Meanwhile, the humidity increased to 64%, despite the ventilation running on the highest setting.
The system’s filter is clean, so that can’t be the problem. The fan itself works; there is airflow. But this can’t be what the system was designed for: First, the fans on the highest setting are difficult to use because they are too loud at 50 decibels. And then even this highest setting can’t maintain the current humidity level? I don’t understand. In my opinion, these fans are completely ineffective.
Since our building is very well insulated, I actually have to air out the room by opening windows three times a day, otherwise the humidity quickly approaches 70%. Three times a day! This is really annoying and should not be necessary with a decentralized ventilation system.
Am I missing something here? Is this the case with all ventilation systems?
I would greatly appreciate any input. On one hand, because I would like to find a solution [different fans?]. On the other hand, because I find the situation so unbelievable. It can’t be that these "things" have no effect...
Best regards,
Markus
G
Gecko192725 Oct 2022 08:33Steffi33 schrieb:
This morning, it was 12 degrees Celsius (54°F) outside with 91% humidity. Inside, it was 20.5 degrees Celsius (69°F) with 64% humidity.
Should we ventilate or not??? 🙄 If the outside air is warmed to 20.5 degrees Celsius (69°F), its relative humidity would be 54.5%, which is 10% lower than your current indoor humidity—so ventilate!
For 12 degrees Celsius (54°F) cold outside air to raise the indoor humidity (at 20.5 degrees Celsius / 69°F) above 64%, it would need to have a relative humidity of 108%, which is impossible.
At 70% relative humidity, you can always ventilate when the outside temperature is below 15 degrees Celsius (59°F) because the air will improve the indoor conditions no matter how humid it is.
The weather is currently too warm to achieve significantly lower humidity. Wait for temperatures below 5 degrees Celsius (41°F) in the morning and let us know then if you still end up around 70%.
Currently, the issue of ventilation concerning building-related problems (moisture/condensation or resulting mold) is also insignificant.
With the high outside temperatures, the surface temperature of the wall will be just below 20°C–21°C (68°F–70°F). This practically rules out any condensation. At the moment, ventilation is therefore only necessary in the bathroom and kitchen areas. It can still be done for a better feeling of fresh air, especially when working from home, but humidity does not play a role here.
With the high outside temperatures, the surface temperature of the wall will be just below 20°C–21°C (68°F–70°F). This practically rules out any condensation. At the moment, ventilation is therefore only necessary in the bathroom and kitchen areas. It can still be done for a better feeling of fresh air, especially when working from home, but humidity does not play a role here.
X
xMisterDx26 Oct 2022 23:27I find the debate a bit surprising. I’m currently not living in a newly built apartment (although after 6 years since construction/move-in, the moisture should have mostly dissipated?), but in an older building from around 193x (estimate). Still, my measuring devices show 55-60% humidity in every room except the bathroom and kitchen, even though we rarely heat or ventilate.
That level is hardly achievable at this time of year... it makes you wonder... In the bedroom, right after ventilating, I’ve even seen humidity as low as 40%+, mostly in the morning when it was about 12°C (54°F) outside.
Even on rainy days, humidity in the living spaces never reached 70%, although we tend to ventilate more during rain because I enjoy the sound of raindrops.
Could it be that apples and oranges are being compared here?
At the moment, there’s really no need to worry, as dertill has already explained. Maybe try turning off the decentralized ventilation and just use intermittent airing? The rest strikes me as more of a myth...
That level is hardly achievable at this time of year... it makes you wonder... In the bedroom, right after ventilating, I’ve even seen humidity as low as 40%+, mostly in the morning when it was about 12°C (54°F) outside.
Even on rainy days, humidity in the living spaces never reached 70%, although we tend to ventilate more during rain because I enjoy the sound of raindrops.
Could it be that apples and oranges are being compared here?
At the moment, there’s really no need to worry, as dertill has already explained. Maybe try turning off the decentralized ventilation and just use intermittent airing? The rest strikes me as more of a myth...
W
WilderSueden27 Oct 2022 10:01Physics is physics, it should be the same in your world too 😉 With certain changes to the parameters, of course, you get different values. If it’s 10 degrees Celsius (50°F) outside and 24 degrees Celsius (75°F) inside, the air will be much drier. In the current weather, the situation is quite sensitive to small changes in the parameters. Continuous ventilation through leaky windows is likely present in an unrenovated older building.
Steffi33 schrieb:
This morning outside it was 12°C (54°F) with 91% humidity. Inside it was 20.5°C (69°F) with 64% humidity.
Should we ventilate or not??? 🙄An update... now it’s cold outside (frost at night, daytime below 10°C (50°F))... our indoor humidity is now around 50–53%..Similar topics