ᐅ Central ventilation system – is humidity recovery necessary?
Created on: 30 Dec 2019 16:17
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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
ludwig88sta schrieb:
I don’t know how much upgrading to an F7 filter at the next change would cost, but according to other forums, it’s supposed to work. It’s definitely worth a try. We have an F7 filter installed as standard — unfortunately, even this doesn’t fully prevent the faint odor when the neighbor lights their wood stove (sometimes you’d think a new pope is being elected over there :rolleyesL
ludwig88sta8 Jan 2020 18:07boxandroof schrieb:
We have a rotary heat exchanger.Why did you choose a rotary heat exchanger? The initial cost (and maintenance?) is probably higher than for standard plate heat exchangers.
**Edit: But the humidity recovery cannot be separately controlled or adjusted either (which is unfortunately also not possible with enthalpy heat exchangers), right?
tomtom79 schrieb:
@Lumpi_LE not with the standard type, since only the fins are exposed to the airflow. With the enthalpy heat exchanger, the air is mixed. That’s what was said in the Rosa Technik forum. Maybe it also depends on the manufacturer.
@ludwig88sta yes, controlled residential ventilation with an F5 filter matIn an enthalpy exchanger, no mixing takes place. The idea that the air is mixed is outdated technology from the 1990s.
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boxandroof8 Jan 2020 18:51ludwig88sta schrieb:
Why did you choose a rotary heat exchanger? The initial costs (and maintenance?) are probably higher than with "standard" plate heat exchangers.There were no special reasons.tomtom79 schrieb:
How is moisture removed and fresh moisture added? via a semi-permeable membrane. The air streams do not come into direct contact.
With a rotor, you always have a mixing of airflows, which is why these devices are generally not used in sensitive areas. (At least not when dealing with large volumes of air beyond the scope of controlled residential ventilation for houses.) When I think about bathroom exhaust after a spicy chili or bean stew, or after eating fish... With a plate heat exchanger, there is less or hardly any transfer of odors, although leaks can never be completely ruled out. If, for any reason (such as explosion protection or hospital requirements), odor transfer or mixing of airflows must be fully prevented, a heat recovery wheel (HRV) is usually replaced by a KVS (heat exchanger valve system), which, however, often exceeds the (financial) limits.