ᐅ Air Too Dry! – Should I Replace My Old Ventilation System with an Enthalpy Recovery Ventilation System?
Created on: 12 Oct 2025 21:10
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Hendrik1980
Dear forum,
We have been living in our well-insulated KFW55 house with a controlled mechanical ventilation system for 2 years now. In winter, the indoor humidity sometimes drops to as low as 20%. I would like to change that!
Unfortunately, our current controlled ventilation system does not include an enthalpy heat exchanger, and it is not possible to retrofit one. Therefore, we are considering replacing the ventilation system. This would cost around 5,000 euros.
Is the effort worth it? Can we expect the indoor humidity to increase significantly after the replacement? What humidity levels can we roughly expect following the upgrade?
We have been living in our well-insulated KFW55 house with a controlled mechanical ventilation system for 2 years now. In winter, the indoor humidity sometimes drops to as low as 20%. I would like to change that!
Unfortunately, our current controlled ventilation system does not include an enthalpy heat exchanger, and it is not possible to retrofit one. Therefore, we are considering replacing the ventilation system. This would cost around 5,000 euros.
Is the effort worth it? Can we expect the indoor humidity to increase significantly after the replacement? What humidity levels can we roughly expect following the upgrade?
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wiltshire13 Oct 2025 22:38RotorMotor schrieb:
So, if someone complains about permanently dry air at 20% humidity, clay simply doesn’t help at all! I also wrote that this is NOT the solution and marked the information accordingly.
RotorMotor schrieb:
Clay can moderate humidity, yes, but nothing more. Now suddenly it can?
RotorMotor schrieb:
That means if someone soon reports fluctuating humidity here, you can feel free to apply clay somewhere... Why stay factual when it gets personal? Suddenly not interested in facts anymore?
Really bad backpedaling.
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RotorMotor13 Oct 2025 22:43It still has nothing to do with the topic.
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wiltshire13 Oct 2025 22:50RotorMotor schrieb:
It still has nothing to do with the topic. That’s what you write, and you avoid addressing the technical aspects.
Regarding the OP’s problem:
As already mentioned, I consider the idea of replacement to be reasonable, but it might not be sufficient. Additional measures could be necessary. There were plenty of suggestions—my comment was just intended to add to that list. This is a “may,” not a “must.”
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Neuer von Da14 Oct 2025 01:23I just turn off the ventilation when no one is home... or I control it using a time schedule.
This way, the humidity in the rooms is usually around 40-60%.
This way, the humidity in the rooms is usually around 40-60%.
Maybe something from practical experience: I retrofitted an enthalpy heat exchanger and am very satisfied. Before, the air was very dry; afterward, it has been consistently comfortable. The ventilation system runs 24/7. Otherwise, only drying laundry and a few plants in the house, no humidifier. So, a clear improvement in comfort, and the unit has been working well for about 9 years now.