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
tomtom79 schrieb:
If you’ve done something, please mention it—I can’t read minds. The problem is that people might misunderstand, that’s all I wanted to say.
No, I didn’t measure anything. The air felt stuffy, you could tell, and our ventilation system only allows 3 speed levels. I removed the nighttime setback. The ventilation runs constantly at level 2, but I would have to check the calculation to know the exact air exchange rate. If I were to build again, I would use both supply and exhaust air in the room without a transfer opening. With the condition that individual rooms can be controlled separately. You’re right. If you can only select levels 1, 2, and 3, it’s clear that you can’t fine-tune it very well with your system. My device lets me freely adjust the fan power for each level, for example: level 1 = 27%, level 2 = 40%, and level 3 = 75% of maximum power. This way, you can precisely calculate the air exchange rate and set it quite accurately. Then you can run level 3 for two hours at certain times or level 1 for five hours, etc.
In theory, yes. In practice, most people hardly adjust the preset levels. They simply switch between levels 1/2/3 and that’s it.
bernie schrieb:Most systems offer these options. It is rather unusual nowadays for the levels to be fixed and unchangeable.
With my device, I can freely set the fan speeds for each level, for example: Level 1 = 27%, Level 2 = 40%, and Level 3 = 75% of maximum power.
Yes, that sounds great. Then you can also move on to fine-tuning if you feel like it.
I believe that many systems are simply set up poorly (and maybe also poorly designed?), which often leads to problems with excessively dry air. Only when proper adjustments no longer help should further steps be taken.
I believe that many systems are simply set up poorly (and maybe also poorly designed?), which often leads to problems with excessively dry air. Only when proper adjustments no longer help should further steps be taken.
Lumpi_LE schrieb:
To properly adjust a system, you would need to control the rooms individually. Unfortunately, that’s not possible with all these single-family home mechanical ventilation units. It’s a real shame that manufacturers don’t offer anything like that.In principle, you’re absolutely right. But mechanical ventilation with heat recovery is already quite a "luxury" that comes at a higher cost. I think if the units became even more expensive because of features like that, hardly anyone would install them anymore.
PS: As someone who usually goes for cheaper options, I will still invest in this luxury of mechanical ventilation with heat recovery for a new build...
Similar topics