Humidistat - needed?

[evluoma]

As a new house owner I have been advised to have a humidistat installed so when we are not in the area, we do not have to worry about high humidity in our home. I was thinking that by keeping the air conditioning on during the summer (while we are gone) at a setting of 80 or below, that would prevent any humidity problems. Any opinions or advice is appreciated, including who you would hire to install a humidistat. Thanks.

[FenneyGuy]

I bought a dehumidifier and keep the humidity around 45% rather than 60+ %.

[villagetinker]

Not sure of the age of your home but most(?) of the newer homes have digital thermostats that have a humidity setting. Also, you absolutely need to keep the AC on when you are not here, or you will probably have a significant mold problem. If you have an older home, contact an AC service (I understand Chuck Farrel is quite good), and have a new thermostat installed. You might also consider a home watch service while you are away.

[SIRE1]

I also thought I should have a humidistat for the summers when we go back to Michigan and had one installed. When I tried to use it, however, I found that the AC would only run if the humidity got above the set level. But the AC would NOT run if the temperature in the house got over the thermostat setting. I had thought the AC would run if either the thermostat OR humidistat settings reach, but I found out it wasn't.

So now, I just leave the humidistat to ON (i.e. not engaged), and rely on the thermostat to trigger the AC when the temp in the house is over 80 degrees. I'm sure some of the newer humidistat will turn on the AC if either condition is met, but just to let you know what to look for if you decide to have one installed.

[anothersteve]

If you have a humidistat, and you are gone for the summer, you can dial it to 60% and set the thermostat to say 76. You are really only worried about controlling the humidity in the house not trying to keep it cool. This way if the humidity goes below 60% the AC kicks on.
Steve

[evluoma]

I also thought I should have a humidistat for the summers when we go back to Michigan and had one installed. When I tried to use it, however, I found that the AC would only run if the humidity got above the set level. But the AC would NOT run if the temperature in the house got over the thermostat setting. I had thought the AC would run if either the thermostat OR humidistat settings reach, but I found out it wasn't.

So now, I just leave the humidistat to ON (i.e. not engaged), and rely on the thermostat to trigger the AC when the temp in the house is over 80 degrees. I'm sure some of the newer humidistat will turn on the AC if either condition is met, but just to let you know what to look for if you decide to have one installed.

Thanks for your reply. In my "online investigation" it appears that you can have your humidistat wired in series or in parallel. When wired in series, both your thermostat and humidistat must be asking for service for your AC to turn on. If wired in parallel, then if either ask for the AC to turn on (by either temp or humidity) then your AC will turn on. I believe it is easy to change the wiring, and it sounds like this might be what you are after. Hope this is useful to you.

[retiredguy123]

My understanding of most Carrier thermostats is that if you set the thermostat to 80 degrees, and turn OFF the humidity feature, the AC unit will run to maintain a temperature of 80 degrees and then shut off. If you set the thermostat to 80 degrees, and turn ON the humidity feature, the AC unit will still run to maintain a temperature of 80 degrees. BUT, when the humidity level in the house is higher than the humidity feature setting, the AC will continue to run and will "overcool" the house to about 3 degrees lower than the thermostat setting, or 77 degrees. So, the house will only be cooled to 77 degrees when you have a high humidity situation. When the humidity is low, the house will be maintained at 80 degrees and never go below that temperature. The humidity feature is a compromise feature that allows you to save energy by using a higher than ideal thermostat setting, while still maintaining some level of humidity control. I would only use the humidity feature when the house is going to be vacant.

[dewilson58]

There was a thread a couple years ago on this topic.


A poster, not me, said all this humidity concern was over rated. His/her point was, why is there not a lot of mold in everyone's garage??


Hmmmmmmmmm. Never thought about that.


Does someone have an answer??


Thanks.

[retiredguy123]

There was a thread a couple years ago on this topic.


A poster, not me, said all this humidity concern was over rated. His/her point was, why is there not a lot of mold in everyone's garage??


Hmmmmmmmmm. Never thought about that.


Does someone have an answer??


Thanks.
You are correct that the humidity concern is over-rated. I just checked my garage and the inside of my house. The garage temperature is 88 degrees and the humidity is 55 percent. Inside my house, the temperature is 75 degrees and the humidity is 55 percent. I would suggest that people buy a thermometer and humidity meter and monitor their house and garage. I think you can buy a combination device at Home Depot for about 10 dollars.

[Toymeister]

You are correct that the humidity concern is over-rated. I just checked my garage and the inside of my house. The garage temperature is 88 degrees and the humidity is 55 percent. Inside my house, the temperature is 75 degrees and the humidity is 55 percent.

What is wrong with this piece of logic is these are measures of RELATIVE humidity. 88 degree air can hold more water than 75 degree air. His garage and home have different levels of absolute humidity.

[Altavia]

Mold tends to start in areas that have poor air circulation such as closets or on the wall behind dressers if you don't remove humidity.

Controlling indoor mold and mildew | Florida Health (https://www.floridahealth.com/indoor-mold-and-mildew.php)

[Professor]

We have been here 10 years and still see no need for something like that. You have the right idea. Leave the air on 80-82 when you are gone and the place should be fine...at least ours has always been.

[JudyLife]

Yes we have a humidistat installed by Munns as we are a long way away & can remotely monitor house temperature & humidity by wifi.

[daca55]

When I had an inspection done on my house before the Warrenty expired the engineer who did it advised me to get a humidistat. He informed me that the humidistat will control the humidity in my house while I am gone for the summer. He said what damages a house down here is not the heat but the humidity. He said that carpets that get wrinkled is because of high humidity.I had Sun Kool install one and I set it at 55% and the AC at 82 and after 10 years have never had a problem plus there is a savings on electricity because AC doesn’t run as often. I bought a humidity gage so my house watch people can check humidity to ensure the humidity is 55 or lower. After 10 years never had a problem with mold or wrinkled carpets. It’s the way to go if you leave your house for a long period.

[Magajane]

We’ve been in The Villages 16 years and leave for about 9 weeks in the summer and set out air at 80 and it’s fine when we get back. That’s what the air conditioning does.

[Sunflower33]

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

[tuccillo]

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.

There was a thread a couple years ago on this topic.


A poster, not me, said all this humidity concern was over rated. His/her point was, why is there not a lot of mold in everyone's garage??


Hmmmmmmmmm. Never thought about that.


Does someone have an answer??


Thanks.

[dewilson58]

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)

[Bethwill]

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

[retiredguy123]

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.

[Lyn Wagner]

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.

[Dr Winston O Boogie jr]

I also thought I should have a humidistat for the summers when we go back to Michigan and had one installed. When I tried to use it, however, I found that the AC would only run if the humidity got above the set level. But the AC would NOT run if the temperature in the house got over the thermostat setting. I had thought the AC would run if either the thermostat OR humidistat settings reach, but I found out it wasn't.

So now, I just leave the humidistat to ON (i.e. not engaged), and rely on the thermostat to trigger the AC when the temp in the house is over 80 degrees. I'm sure some of the newer humidistat will turn on the AC if either condition is met, but just to let you know what to look for if you decide to have one installed.

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.

[anothersteve]

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.

That would actually be a "hygrometer"

Steve

[retiredguy123]

That would actually be a "hygrometer"

Steve
Thanks. You are correct.

[gmdds]

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.

[Dlbonivich]

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.

[willbush]

As a new house owner I have been advised to have a humidistat installed so when we are not in the area, we do not have to worry about high humidity in our home. I was thinking that by keeping the air conditioning on during the summer (while we are gone) at a setting of 80 or below, that would prevent any humidity problems. Any opinions or advice is appreciated, including who you would hire to install a humidistat. Thanks.
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.

[Parker614]

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!

[dougawhite]

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

[renpan]

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 .

[rmd2]

Have one, don't like it, don't use it. I use AC and fans when I am gone.

[sldsld]

As a new house owner I have been advised to have a humidistat installed so when we are not in the area, we do not have to worry about high humidity in our home. I was thinking that by keeping the air conditioning on during the summer (while we are gone) at a setting of 80 or below, that would prevent any humidity problems. Any opinions or advice is appreciated, including who you would hire to install a humidistat. Thanks.

Don't waste your money unless you do not have sufficient insulation. Just set the thermostat at a reasonable temperature such as 82 degrees F and all will be good. We have been doing this for 10 years with NO problems.

[coffeebean]

If you have a humidistat, and you are gone for the summer, you can dial it to 60% and set the thermostat to say 76. You are really only worried about controlling the humidity in the house not trying to keep it cool. This way if the humidity goes below 60% the AC kicks on.
Steve

We have a humidistat which was already in our pre owned home. It was explained to us by Munns that the dial should be set to 60. The air conditioning will not run unless the humidity in the house goes ABOVE 60%. The house can get hot as heck but the A/C will not kick on unless the humidity is higher than 60%. Munns said it doesn't matter how hot the house gets, it is the humidity that is the problem when leaving the house uninhabited for periods of time.

When we left our home after "the season", we kept the thermostat cool setting at 83 degrees and the humidistat at 60. We left the house with those settings for 9 months at a time. Never had a mold problem and the electric bills were minimal.

[mpalazzola]

If your home is new enough to have a Carrier brand thermostat. It most like has a humidity setting. Mold has little to do with temperature, and everything to do with humidity. There's no mold in the dessert and mold exists in glaciers. Set your factory thermostat to control humidity at 50-55%, and set the AC to 80 deg. You are all set. Now people will tell you the house needs to be cooler: Well if you set the house cold enough, the summer humidity will condense around windows and creat water.

[coffeebean]

There was a thread a couple years ago on this topic.


A poster, not me, said all this humidity concern was over rated. His/her point was, why is there not a lot of mold in everyone's garage??


Hmmmmmmmmm. Never thought about that.


Does someone have an answer??


Thanks.

Son of a gun! Never thought about that. It is true, we have lived in south and central Florida for a total of 35 years and never have had a mold problem in the garage. Good point.

[ts12755]

I've been in Central Florida for 40 years and never met anybody with a humidistat installed. I also used to do energy audits. If you're going to be gone for a while just leave the AC set at 84 degrees to keep the humidity out of the house.

[Bonsai Golfer]

As a new house owner I have been advised to have a humidistat installed so when we are not in the area, we do not have to worry about high humidity in our home. I was thinking that by keeping the air conditioning on during the summer (while we are gone) at a setting of 80 or below, that would prevent any humidity problems. Any opinions or advice is appreciated, including who you would hire to install a humidistat. Thanks.

I am gone for 5 months during the summer. i do not have a humidistat. I set my thermostat for 88 degrees but for one hour each day it drops to 74 degrees. That insures that my A/C will run for at least one hour each day to dry the air and keep the humidity under control. I have had no problems with this approach and my electric bill is only about $35/mo. for an Amarillo.

[Labanz]

I am an the owner/technician for Good Guys Air Conditioning and resident of LaBelle here in the villages with just over 40 years experience as a technician. There are many people here that have made a comment if you keep your air-conditioning on and set to 80 it will control the humidity within the home. That advice is correct.
There is also a couple comments about most carrier thermostats have a humidity setpoint that will actually over cool the space if humidity setpoint gets excited. The only comment I would add to that is that it’s not most carrier thermostats it is certain models but not all. I chose to replace mine with one that connects to the internet so I can be alerted if there is a problem.

Before moving to the villages I had a home I used for vacation in the Tampa area. For the last five years I kept the thermostat at 80° and experienced a humidity reading of between 40 and 50% all summer. The home was built in the late 70s and was notNearly as well as the homes here in the villages. If you keep the Internet on why you’re not here I would certainly recommend a thermostat that will monitor and alert you if there is an issue with either humidity or temperature exceeding your setpoint. If you have any questions you can contact me directly.

[dewilson58]

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.




Thanks.


Wondering about snowbirds who are gone and not exchanging the air.


:shrug: