ᐅ Central ventilation system – is humidity recovery necessary?
Created on: 30 Dec 2019 16:17
L
ludwig88sta
Hello everyone,
for our planned single-family house with 2 floors and a basement, we have decided on a central ventilation system for all rooms with heat recovery within the thermal envelope. The brand and model are not yet determined.
I have read here on the forum a few times about an additional moisture recovery feature (MRF?), since otherwise the indoor air tends to become too dry (of course, the ventilation system also removes the moisture that naturally occurs in the room, which usually makes the air feel comfortable). I wanted to ask if anyone can confirm these issues and whether this is more common in timber frame houses or also occurs in brick houses?
Did you install additional moisture recovery in your ventilation system? How much extra cost does it involve? I assume there are also additional maintenance costs because it involves another motor and related components.
Best regards
ludwig88sta
for our planned single-family house with 2 floors and a basement, we have decided on a central ventilation system for all rooms with heat recovery within the thermal envelope. The brand and model are not yet determined.
I have read here on the forum a few times about an additional moisture recovery feature (MRF?), since otherwise the indoor air tends to become too dry (of course, the ventilation system also removes the moisture that naturally occurs in the room, which usually makes the air feel comfortable). I wanted to ask if anyone can confirm these issues and whether this is more common in timber frame houses or also occurs in brick houses?
Did you install additional moisture recovery in your ventilation system? How much extra cost does it involve? I assume there are also additional maintenance costs because it involves another motor and related components.
Best regards
ludwig88sta
bernie schrieb:
You have to get familiar with your device a bit, just like with heating, and experiment. I can set the fan speed for three levels in percentages as I like. So, I have set the "low" and "medium" levels to lower speeds and programmed them to run at different times throughout the day. Currently, we have an air exchange rate of 0.3, which is more than sufficient—the 0.5 rate is not necessarily required. Can’t every system do that? But reducing the air exchange rate and then saying the rooms don’t dry out is basically what we’re saying. Here’s another tip: just turn it off, then you get >50% and can ventilate manually again.
tomtom79 schrieb:
Can't every system do that? But reducing the air change rate and then saying that the rooms won’t dry out is basically what we’re saying. Here’s a tip: just turn it off, then you have >50% and can ventilate manually again.Don’t exaggerate. He is right.
You don’t have to overdo ventilation either; 0.5 is high. Normally it’s 0.3. Turning it down is therefore not bad advice.
face26 schrieb:
Just to point out again, when retrofitting you can switch it out. In summer, you might even get more moisture out... Does anyone happen to know the best way or place to store an unused heat exchanger?
Why do I ask?
We replaced our enthalpy heat exchanger with a standard heat exchanger because even after 1.5 years we couldn’t reduce the indoor humidity.
The removed enthalpy heat exchanger is currently stored in its box in the garage.
Could there be any issues reinstalling it in maybe 1-2 years if we decide to switch back?
face26 schrieb:
In summer, you might even be able to get rid of moisture more easily...In summer, the bypass is activated. That means the air bypasses the heat exchanger anyway.face26 schrieb:
Yes, exactly. It’s even recommended because the structural drying is finished, and then in winter you can use enthalpy recovery and in summer you can switch it off.Isn't it more practical to bypass in summer?
Why would you run air through a heat exchanger during summer?