Ducting dehumidifier where to place intake and exhaust
steven765
| Posted in General Questions on
With the minisplit now up and running. Humidity runs from 45-55% in the attic and 50-60% in the basement. Considering if i put a dehumidifier in the attic or basement. First is one better than the other? On one hand the humidity rises but basement always seems more humid.
Would ducting the intake in the basement and output to basement and first floor disturb the ERV balance?
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Replies
Without knowing the temperature the humidity numbers don't mean much.
In theory the place with the higher dew point will cause the dehumidifier to remove more moisture. A practical concern is that dehumidifiers produce a fair bit of heat, you may want to put it where the heat can be handled.
I should have specified Relative Humidity. But regardless it's inside so between 67 and 74 this time of year. Both spaces are conditioned.
Relative humidity without a temperature attached means nothing.
At 60% RH at 67F the air moisture content is 60 grains per pound. At 50% RH and 74F it's 64 grains per pound, they're essentially the same.
Attics tend to be a sort of collection point for moisture, because moist air rises, basements are often a source of moisture. The usual place to put a dehumidifier is a basement. Chances are, you'll have easier access to power in the basement too, which might also be a concern. The easiest thing to do if you're not sure is to try both locations, maybe a week or so in each location, and see which spot works best. If it were me, I'd just go with the basement unless I had a specific reason to need to be concerned with the attic.
Bill
I have a dessicant dehumidifier in my encapsulated attic to remove moisture buildup. It has an exhaust port which goes out the side of the house. The set point for the controls is set to 40% RH. The operating range for equipment is 0F to 100F which works well in Zone 6A.
Note: my heated garage has diffusion ports (Passive) — and operates between 45F to 50F - which is good enough.
The way I see it the summer time attic relative humidity is irrelevant. The question is how close to the dew point is the attics temp in the winter.
Your nose will tell you if the basement is a problem in the summer. Does it small musty?
Walta