Hello everyone, the title already describes the problem. Approximately 20% humidity in all living and sleeping rooms. We moved in about two weeks ago. That can’t be normal, right? I expected such low humidity only after 2-3 years, but not right from the start...
The first night in the house was really horrible. On top of that, we have been dealing with colds and coughing the whole time. We now have a humidifier running all night in the bedroom (starting in the evening, about 12 hours total) and wake up with around 35-40% humidity.
Could something be set incorrectly in the mechanical ventilation system with heat recovery, or is this low humidity normal in a new house?
What can we do? Apart from the bedroom, we don’t notice it being a problem in any other room. Enthalpy exchangers are supposed to increase humidity by a maximum of 5%, right?!
Thanks for your feedback and best regards
The first night in the house was really horrible. On top of that, we have been dealing with colds and coughing the whole time. We now have a humidifier running all night in the bedroom (starting in the evening, about 12 hours total) and wake up with around 35-40% humidity.
Could something be set incorrectly in the mechanical ventilation system with heat recovery, or is this low humidity normal in a new house?
What can we do? Apart from the bedroom, we don’t notice it being a problem in any other room. Enthalpy exchangers are supposed to increase humidity by a maximum of 5%, right?!
Thanks for your feedback and best regards
RotorMotor schrieb:
It’s best to refer to my calculation if you think keeping windows open is beneficial for humidity! Your calculation applies to closed containers, not a house where there is already a 1 cm (0.4 inch) gap under the doors and windows are left open at night.
Our house has 45-55% humidity without a mechanical ventilation system, and we also have many flowerpots around.
R
RotorMotor3 Mar 2023 11:05Nida35a schrieb:
Your calculation applies to closed containers and not to a house That is not correct.
The calculation is generally accurate.
Of course, there can be mixing, which on average affects the humidity.
Fundamentally, it is important to understand relative and absolute humidity.
Then it quickly becomes clear that the problem is not inherently caused by the controlled mechanical ventilation system, but by "cold, dry air."
And letting this air into the house through windows has only disadvantages and no benefits.
By the way, you cannot retrofit an enthalpy exchanger in windows, but fortunately you can with controlled mechanical ventilation.
Nida35a schrieb:
Our house has 45-55% humidity without controlled mechanical ventilation, That is probably because you have a relatively low overall air exchange rate, despite having partly open windows.
Or you might be adding a lot of moisture through plants, cooking, showering, etc.
W
WilderSueden3 Mar 2023 11:26I find the difference quite striking. We have been living here for three weeks now, and I still ventilate several times a day because the (decentralized) mechanical ventilation system on medium setting can’t fully remove the construction moisture. At first, the humidity was constantly around 60%, but it now seems to be settling at about 55%.
What kind of house do you have? Construction method, interior plaster, etc.?
What kind of house do you have? Construction method, interior plaster, etc.?
Y
Ypsi aus NI3 Mar 2023 11:39We have already turned on the underfloor heating and kept the window open all day long, but it doesn’t help with the humidity. It stays around 20%.
Now we will wait and see how things develop once all the rooms are furnished and set up. For example, I can’t really use the kitchen yet, so it’s not adding any moisture. But we do have an air conditioner that will significantly dehumidify the air during the summer. Let’s see how the indoor conditions feel then.
Now we will wait and see how things develop once all the rooms are furnished and set up. For example, I can’t really use the kitchen yet, so it’s not adding any moisture. But we do have an air conditioner that will significantly dehumidify the air during the summer. Let’s see how the indoor conditions feel then.
Newly occupied just a few days ago, 20% relative indoor humidity:
In winter (when it is cold outside!), even if it is raining outside, keep the mechanical ventilation system at the lowest setting and do NOT open windows to ventilate!
In spring/summer/autumn, when it is warmer, open windows depending on the humidity and temperature of the outdoor air; this will stabilize over the next few months. The building materials, furniture, etc. need time to reach an appropriate equilibrium moisture level.
In winter (when it is cold outside!), even if it is raining outside, keep the mechanical ventilation system at the lowest setting and do NOT open windows to ventilate!
In spring/summer/autumn, when it is warmer, open windows depending on the humidity and temperature of the outdoor air; this will stabilize over the next few months. The building materials, furniture, etc. need time to reach an appropriate equilibrium moisture level.
Ypsi aus NI schrieb:
also keep the window open for a longer timeAs mentioned, during winter or when outside temperatures are low, ventilating actually tends to lower the indoor humidity. (The air warms up inside the house -> relative humidity decreases). That’s also why drying screed and removing construction moisture from the house often works more easily in winter (if you ventilate frequently and heat the house accordingly).I don’t have specific tips; my approach currently would be to counteract with small measures (plants, a small indoor fountain, possibly a humidifier where it’s most problematic for you) and otherwise wait and keep monitoring.
Similar topics