control humidity with varies ventilation

[Kakanthony]

Hi ,

I am trying to control the humidity based on varying the ventilation flow rate?

is that possible to do it in apache?

try to control the humidity from 30% to 70% and with varying the Outside air rate.

thanks

[Complex Potential]

It is possible to set up a profile to try to keep the RH within those limits but fresh air alone may struggle at the low end, especially in winter.

Try this profile on the aux vent

gt(rh,50,20)

That should mean the air goes off if the RH drops below 40% and will be at maximum flow if the RH goes above 60%.

Please note that the above profile should work best in rooms with high internal latent gains where fresh air should almost always provide a drying effect.

An effective way of raising the RH is to turn the heating off at times when the RH has dropped too low, especially in winter.

[farahghanem]

Another way to control humidity would be cooling to dew point, and then reheating, or using dessicant wheel. Both methods allow for varying ventilation rate.

It is good to note, that according to your project's weather file, some dehumidification strategies work while others do not. For example in climate zone 1 the problems with humidity appear in the summer rather than winter.