Those in Humid Areas, What Summer Indoor Humidity (RH) Do You Try to Maintain?

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I shoot for 55%. We don't have a dedicated dehumidifier, but recently had a new HVAC system installed which is a communicating dual stage type and uses an advanced thermostat (Honeywell Prestige IAQ) which displays current indoor RH in smaller font just below the temperature.
 
45 in summer or less with dedicated dehumidifiers. Easier on AC too.
Winter raise humidity try to stay above 35 prefer 45 to 55.
 
When I was in hotels I learned that 40-50% was optimal - only reason I learned this was because the large well known chain I worked for had a brand standard of I think it was 45 or 48%.

I just had my 19 year old heat pump replaced, my old unit was so inefficient that it easily maintained low 40% because it had to run so long to cool. Now the new unit is cooling properly so right now I am lucky to hit the low 50's with a thermostat setting of 74, hoping it gets into 40% once we get further into the summer and it is running more often. For me mid-high 50's it starts getting too muggy inside and I end up fiddling with my ceiling fans to stay comfortable at 74 degrees, low 50's the 74 starts feeling decent and 40's the 74 is just perfect.
 
I don't try to maintain any specific level, just setting the thermostat to a comfortable level. An A/C IS a dehumidifier. It makes little sense to run a separate indoor dehumidifier in summer in the midwest US because it is essentially also an air conditioner yet a less efficient one, with a shorter effective life:cost ratio, that dumps a lot of heat into the room instead of exhausting outdoors (which is why it is called a dehumidifier instead of an air conditioner, functionally they both work pretty much the same besides this).

If you have a specific area where moisture is coming in and cannot seal it any better than it presently is, it would make more sense to put a portable air conditioner in that room except in the colder months of the year when you are running a heater instead of A/C, then a dehumidifier makes sense if you have a particular moisture problem (leaking basement/foundation/etc) instead of the more typical desire to increase humidity in winter heating months.
 
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Originally Posted by Dave9
I don't try to maintain any specific level, just setting the thermostat to a comfortable level. An A/C IS a dehumidifier.
...

This. The central air dehumidifies to whatever it is as it cools the house.

Right now it is 92°F and 73% relative humidty according to my weather gauge outside, inside is 79°F and 58% RH (A/C is set to 80°F).
 
Under 50%. If you live in a humid area alot of utility companies offer a energy audit that offers a blower door test. My coop charged $50 and gave me a box of goodies. This test they put a fan in the front door with a canvas frame that seals the fan to the door way. Adjust fan speed to a certain air pressure reading and take a cubic foot per minute reading which shows how tight your house is. Lower the cfm reading the tighter your house is.
 
Originally Posted by pezzy669
When I was in hotels I learned that 40-50% was optimal - only reason I learned this was because the large well known chain I worked for had a brand standard of I think it was 45 or 48%.

I just had my 19 year old heat pump replaced, my old unit was so inefficient that it easily maintained low 40% because it had to run so long to cool. Now the new unit is cooling properly so right now I am lucky to hit the low 50's with a thermostat setting of 74, hoping it gets into 40% once we get further into the summer and it is running more often. For me mid-high 50's it starts getting too muggy inside and I end up fiddling with my ceiling fans to stay comfortable at 74 degrees, low 50's the 74 starts feeling decent and 40's the 74 is just perfect.


See if a tech can come out and lower the blower fan speed on the new system. It might be set by default to a faster blower fan speed than is optimal for dehumidifying. If it is a dual stage or multi stage "communicating" system and has the newer ecm type blower fan motor or whatever it can likely vary the blower fan speed by the smart thermostat they installed with it (usually a Nest or a Honeywell IAQ).

You want a slower fan speed so the evap coil gets colder and condenses water out of the indoor air more effectively
 
Originally Posted by atikovi
Is humidity even adjustable on newer A/C systems? I'm still using a 29 year old unit.


Some of the newer thermostats allow you to run the ac to dehumidify. What it does is allow the temperature to drop a few degrees below the set point if needed to remove the humidity.
 
Heating, cooling homes, now adjusting the humidity. My home is set to ambient temps, and humidity as supplied by our weather system. I've spent my life doing it that way,no need to change now.
 
Originally Posted by LoneRanger
I shoot for 55%. We don't have a dedicated dehumidifier, but recently had a new HVAC system installed which is a communicating dual stage type and uses an advanced thermostat (Honeywell Prestige IAQ) which displays current indoor RH in smaller font just below the temperature.


60 with my basement. Normally not that hard to maintain and I'm smack in the middle of the Great Lakes.
 
I'll tell you what. I can deal with high and low temperatures pretty well. See previous threads where some of you guys make fun of me for keeping temps outside of our bedroom in the 50's all winter! lol

One thing I can't deal with, is high humidity. I simply can't sleep at night if the humidity is too high.

Originally Posted by Silk
Heating, cooling homes, now adjusting the humidity. My home is set to ambient temps, and humidity as supplied by our weather system. I've spent my life doing it that way,no need to change now.


Do you guys have basements there?

the previous owners of my home had a dehumidifier in the basement, but weren't using it the several times in the fall that we walked through.

There was white and yellow mold in two different parts of the basement that we had them take care of, and to check if it was active.

Anyway, the basement smelled very musty until I setup two dehumidifiers. A few months later and the musty smell is gone.

We store a decent amount of stuff downstairs, so it's nice to not worry about moisture damage, smell, and rust (to a certain degree)

//

Upstairs, we let the humidity do its thing. I usually run the window unit the large upstairs only for de-humidification, since it's too small to keep up with temps.

I honestly don't mind 80F+ and low, low humidity. We turn on the second, large window unit when the smaller one can't keep up with very high humidity days or the temps get threaten to exceed 90F.

Fans are A LOT more effective when the humidity is AZ low.
 
My 5 ton, dual compressor AC unit cools my Florida home quite nicely. However, the humidity varies quite a bit. 55% is common once it's settled down.

However, I don't care one bit for trying to maintain a specific humidity. I'd rather have the home cool when I want it cool. I don't care what others say about RH and how you feel, it's not really true. Hot is hot and cool is cool.

As far as I am concerned, a humidistat is good for maintaining low humidity when NOT in the house.
 
That's not my experience, Cujet. The other day, it was low 70's F and >70% humidity, with all of the windows open. It felt completely gross and, just doing chores around the house, I became sticky quickly.

In the middle of the summer, with the windows shut and an A/C unit maintaining low 80F+ and low humidity, my sweat evaporates much more quickly and I feel much better overall.

Conversely, we always keep our A/C running in the bedroom. Before we got the dehumidifier, the room would be clammy as heck if the A/C didn't run long enough to actually dehumidify. It could be 68F and still not feel comfortable for sleeping. After the dehumidifier, with RH maintained <50%, it's much better.
 
Originally Posted by Eddie
80 F and 68% at my home in SW FL.


That's not normal. It may be OK for you, but that's not normal, you super-human freak! :p
 
Kentucky has its humid times, and my living room/family room is built halfway into a hill. I run a dehumidifier in addition to the A/C, and in the warmer months with the A/C set to 70º I have trouble getting below 60%. With that said, I replaced the unit(heat pump/AC) back in December when both the heat pump and electric heat coil control board decided to give up at the same time. I haven't been through a summer yet with the new system, so I'll see how it does with keeping humidity under control. It replaced a system installed in 2006, when the place was built, so the old system wasn't exactly extremely old.

In the past at least I've found a separate dehumidifier in the living room beneficial as it allows me to be comfortable at a higher thermostat setting.

The new heat pump/AC did come with a fancy new thermostat that I haven't dug into yet to see what all the options are-it's been mild enough lately that I've either only turned the A/C on every few days to circulate some air, or otherwise turned it on for a few hours before bed to cool things off. I kept track and I think only turned the A/C on about 6 or 7 days in April, although I also had to turn the heat on a couple of days...
 
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