How low to dehumidify?

[Charles Krug]

List:

Had some mildew problems, which I more or less fixed by adding a dehumidifier.

According to the Energy Star website, the "right" size for our basement is about half the capacity of the smallest unit made, even when choosing the next damper option than our actual condition.

Anywho . . .

I have a hygrometer set across the basement from the dehumidifier which is now reading >45% RH. Is that too agressive?

I'm a bit humidity shy after the problems we had, but I'm afraid I didn't measure the humidity before adding the dehumidifier.

Is there a Magic Number (tm) which will ensure no mildew grows, assuming nothing gets soaked from a burst pipe?

Thanx

Charles

[Choreboy]

The University of Florida says no mold will grow below 62% and not much will grow below 70%. I assume that's true of mildew.

I don't know how much power your appliance uses, but how about a timer so it will turn on and off during the day? A little fan that came on at the same time could help prevent damp corners.

[Charles Krug]

So anything below 55% would be good. I'm not gonna assume that a $5 BB&B hygrometer is gonna win any metrology awards for accuracy.

45% feels "odd" somehow, but I'm not sure whether that's real or just my skin transitioning from damper to drier air.

Our dehumidifier has a control that's calibrated in nonsense units. "4" seems to run continuous and give me this 45%.

I'll see if I can't get it to cycle and give me around 50% RH.

Thanks

[Art]

To avoid dust mites stay below 50%.