# At what humidity level do you set an a/c humidistat?



## 3kids4me (Aug 5, 2009)

We just got new a/c and the thermostat also lets you set humidity.  What would a normal setting be?  We keep the thermostat set on 71. 

Thanks for any help!!


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## Htoo0 (Aug 5, 2009)

Probably 45%. Assuming the new A/C has a humidifier/dehumidifier built in. Just because a thermostat has such a function doesn't necessarily mean it can perform it but if it came with the new unit then my guess is it does have at least one or the other of not both.


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## 3kids4me (Aug 5, 2009)

It doesn't exactly, but from what I understand it sets the fan to low and continues to cool in order to remove humidity without lowering the temperature.  Although it apparently just turned itself off before it reached the 55% we had it set on....it was 62% in the house...so I don't know if it even works correctly.


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## hvacrsteve (Aug 5, 2009)

It is only going to dehumidfy until the set point is reached (temperature set point). Otherwise it would over cool the space.
If it is really hot, it will dehumidfy better than when it is mild, it also takes awhile to remove the stored humidity that is in your home, walls, furniture, carpet etc.


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## Chrisky (Aug 5, 2009)

3kids4me said:


> We just got new a/c and the thermostat also lets you set humidity.  What would a normal setting be?  We keep the thermostat set on 71.
> 
> Thanks for any help!!


Not too sure about humidity.  On our system, when the AC is on, it's the cooling that removes the humidity.  We only set the humidity when it gets cooler outside, to prevent too much moisture accumulating on our windows.
You must like it very cold in your house, we keep our AC set to 76 to keep the house cool and for energy conservation.


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## Htoo0 (Aug 5, 2009)

I have a humidity sensor and temp gauge as part of my clock. It's my understanding a home's humidity should ideally be between 30-50% with 45% as best. Our last home actually did have a humidifier built in to the central heat & air. It was to be used to add moisture in the winter months when air tends to be drier. Current home has a heat pump system and without any help it the sensor usually reads between 30-40% in the winter and 40-55% the rest of the year.


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## DeniseM (Aug 5, 2009)

3kids4me said:


> We just got new a/c and the thermostat also lets you set humidity.  What would a normal setting be?  We keep the thermostat set on 71.
> 
> Thanks for any help!!



I'm just astounded that you set your AC so low!  Is that for medical reasons?  If we set ours on 71º it would never shut off from May - September!


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## Htoo0 (Aug 6, 2009)

DW wants it set at 72. I want it at 75. We wind up bouncing it between 73 and 74.


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