I take care of my brothers 1100 sq ft villa and keep the air on 80 and keep all shades closed. He has never had a problem. Just FYI

Mold is more likely with high relative humidity and infrequent air exchanges. I believe the current thinking is relative humidity for extended periods of time over 70% is potentially a problem. Garages most likely have frequent air exchanges since the doors are opened on a regular basis. In the summer, high temperatures in a garage make high relative humidities for extended periods of time unlikely. For example, if the temperature is 95F, relative humidity over 60% is nearly impossible. As the temperature in the garage cools in the evening the relative humidity will increase but you won't typically have high relative humidities for extended periods of time.

:coolsmiley:
(not a pun)

My dehumidifier comes on whether or not the air conditioner is ready to come on, if it is too humid. We keep our thermostat at 80 in the daytime. Our house was built in 2014

I think the answer to the OP's question is that, if you keep the AC setting on about 80 degrees, you don't need a dehumidifier to prevent mold or other humidity problems in your house. A humidistat is just a device to measure the relative humidity. You can buy one at Home Depot for about 10 dollars. It is not a dehumidifier.

The nest
 

The greatest thing is have a nest installed for you heat and air. We go to Buffalo and with the nest you can see the humidity in the house and you can change your air or heat any time you want. I go on my phone or iPad and change the temperature any time I want from Buffalo to control what is going on in the house. Love it!!! Also have a front door camera and i can see if my grass has been cut, if my sprinklers are running ok. Love it. And i had Lowes install a WiFi garage door opener and if i need to open the door for lawn guy to adjust sprinklers i can open it from Buffalo. Sure takes the worries out of what is going on at my house. Just saying.

That is actually the whole idea behind having a humidistat. If you set the AC to come on at 80 when you are away in the summer, it will run all day and much of the night. Since the humidity and not the heat is what is harmful to the inside of your home, a humidistat will only allow the AC to come on when the humidity rises above the pre set level regardless of temperature. It is not intended as a dehumidifier when you you are occupying the home. I had one back in the 80s when I was a Sarasota snowbird.

That would actually be a "hygrometer"

Steve

Thanks. You are correct.

Whole house dehumidifier
 

What you need is a whole house dehumidifier, not a small portable unit. It is all about relative humidity.

We are full timers, and it is always on (not always running), and the humidity level is set at 50%. This means that the AC runs way less. For example last summer we kept the AC at 80, with the dehumidifier at 50%, and were more than comfortable, even cool sometimes. When we leave town we leave the dehumidifier at 50%, but raise the AC to 87.

I would rather run the 110V unit to keep the moisture out vs. the 220V AC. It doesn’t make sense to run the AC just to draw moisture out...you don’t need it cooler, just dryer.

Case in point...this morning. The dehumidifier is running now because the dew point if very high. It is plenty cool enough outside...so only need it dehumidifier, not cooler.

Hope this helps.

I really never thought you needed anything besides running the air. I always kept my air set at 80 degrees when I’m not there and things are fine. My unit at the beach on the water has much higher humidity than a house here and I have never had a problem in 10 years.

Had Munns install a Honeywell Vision IAQ pro (all one unit that replaces unit on wall). All we do is push the hold button when we leave and it monitors these two points - heat 87 & humidity 60% - when we get back after summer we just hit cancel to go back to reg settings;do not get the separate unit as many individuals have problems trying to work two units;our electric drops down to 1/3 & house is comfortable & we never have to worry about mold;have had it since Mar 2011 - going on 9 yrs and love it;not one service call since installing.

Definitely worth it. We did not live here for the first 2 years we owned our house. Munn's installed ours and showed us how to use it. Very easy. It saved us so much money. Makes no sense to have the a/c run all the time when all you really need is to keep the humidity under control so you don't get mold. I would say it paid for itself in just a couple/few months. Munn's is very reliable!

Maintain good air circulation while away. Leave all interior doors open, including closets, and run all ceiling fans on low.

Our home is 14 years old. We always leave the thermostat to 80 when we leave inh May. We have seen no evidence in mold even when we had our bathroom remodeled .