Here in Florida, our brutal summer of heat and humidity is about to begin. My question is which is better, running the A/C or running a couple of dehumidifiers. I pay a flat fee for the electric hook up so cost of electricity is not an issue. I guess my concern is even if I set the a/c to 90, it still would be running 20 hours a day for the next 4-5 months. Seems like it would shorten the life of the a/c unit. If I were to use dehumidifiers I would set one in shower, the other would be placed in the kitchen to drain into the sink. I would then leave the grey water valve open to drain onto the ground. That's my idea anyway. Any thoughts. Thanks.

This question was previously addressed on the forum. My immediate thought was, a dehumidifier would generate too much heat.I was corrected by a Florida resident who said a dehumidifier takes more moisture out of the air than A/C. And, the small amount of heat generated by the dehumidifier is easily overcome by the A/C.I don't have enough experience in the Florida heat/humidity. But now, to me, it makes sense to run a dehumidifier along with the A/C.

I ran my AC all summer every year in Orlando. I also had a dehumidifier with grey tank open. Cheaper to replace an AC every 7 or 8 years than fix all the heat related damage.

I live in Florida and the only time I use a dehumidifier is during the cool months when it is too cool for the AC and not quite cool enough for heat. A properly sized AC unit will remove more moisture and not add heat to the area. A dehumidifier will only lower the humidity somewhat and, in the best case scenario, will not lower the temperature. You need to run the AC unit as much as it takes to keep you comfortable. The humidity down here can be around 80%+ and just opening one door will allow a bunch of moist air in to your coach. Run your AC and maybe a fan or two to move the air inside the coach. With air movement you can keep the temperature a little warmer.

De-humidifiers would work great, but create too much heat with no practical way to vent them directly to the outside. Running them would just cause your A/C to work that much harder. :@

my 2 cents. I have a degree in HVAC I worked a/c service for years. Its harder for your a/c unit to remove the moisture (humidity) than it is to change the air temp. Run the dehumidifiers you will find that your a/c will be able to keep up with the heat load if they're operating properly.

A/C or de-humidifier? | Good Sam Community

tropical36
Explorer
May 24, 2016
bobkatmsu wrote:
Here in Florida, our brutal summer of heat and humidity is about to begin. My question is which is better, running the A/C or running a couple of dehumidifiers. I pay a flat fee for the electric hook up so cost of electricity is not an issue. I guess my concern is even if I set the a/c to 90, it still would be running 20 hours a day for the next 4-5 months. Seems like it would shorten the life of the a/c unit. If I were to use dehumidifiers I would set one in shower, the other would be placed in the kitchen to drain into the sink. I would then leave the grey water valve open to drain onto the ground. That's my idea anyway. Any thoughts. Thanks.

The thing I do with stick houses for some of the snowbirds here in FL, is to put a Dehumidifier control, connected in series with the thermostat. with the DH set at about 65% and the thermo at 80F. This setup requires that both must be satisfied for the A/C to run and I think the best of both worlds. Just saying that if you can do a setup like that in your coach, then it should do fine.
As for our coach, it sits in the driveway when not in use, with the vents open and nothing else. Been doing this for years, with no ill effects, so no use to change things now, I don't guess.
Airstreamer67
Explorer
May 24, 2016
Here is semitropical Louisiana I use a dehumidifier when the coach is not being used. I store it under a canopy that avoids direct rays of the sun. The dehumidifier eliminates any problems with the very heavy, humid air down here which could otherwise lead to mold and other such consequences.

When the RV is in use, I run the dehumidifier and whatever else is appropriate: In the heat, the air conditioner does the cooling and the dehumidifier helps a lot with comfort. In the cold, the heater does the warming and the dehumidifier helps a lot with comfort, especially when cooking with propane which adds moisture as well.
Sez_Hoo_
Explorer
May 14, 2016
George Beggs wrote:
When I only had AC the temperature would be down but there was so much humidity that the motor home was clammy and very uncomfortable. The best thing I ever did was buy a dehumidifier. Now I stay cool and dry.

When there is more humidity than heat that will happen or if your a/c is oversized. It will lower the temp quickly but not run long enough to remove the water vapor in the air.
J-Rooster
Explorer
May 14, 2016
I'm in a cool, moist, damp climate in the Pacific Northwest and my dehumidifier is the greatest gadget that I have inside my coach, besides the DW.
wolfe10
Explorer
May 14, 2016
chuckftboy wrote:
If the OP is talking about during storage and that storage is in direct sun, then the inside of the coach can easily reach more than 120 degrees without a/c. A hot dry interior is not good for wood products and plastics in which case, a/c is the better option.

I agree-- in the sun, use the A/C.

If under cover or indoors, a small house-type dehumidifier is the way to go. Been there, done that on boats and motorhomes for several decades.
chuckftboy
Explorer
May 14, 2016
If the OP is talking about during storage and that storage is in direct sun, then the inside of the coach can easily reach more than 120 degrees without a/c. A hot dry interior is not good for wood products and plastics in which case, a/c is the better option.
fcooper
Explorer
May 14, 2016
I'm interpreting the OP's intent differently than most here. I think he is asking about what's best for the motorhome being stored instead of while he's living in it.

I have a similar situation here in coastal georgia with my motorhome stored in partial sun and it's really humid here! When we're not using the motorhome, I just run a dehumidifier sitting in the kitchen sink set as Wolfe10 suggested at 45%. I leave the valve open so it can drip outside.

When we're using the motorhome, the dehumidifier stays home and we run the roof air.

Fred
George_Beggs
Explorer
May 13, 2016
When I only had AC the temperature would be down but there was so much humidity that the motor home was clammy and very uncomfortable. The best thing I ever did was buy a dehumidifier. Now I stay cool and dry.
rockhillmanor
Explorer II
May 13, 2016
Here in Florida, our brutal summer of heat and humidity is about to begin. My question is which is better, running the A/C or running a couple of dehumidifiers.

It's not an either or issue.

When in Florida in a MH parked in the sun.....AC is a must period.

My first summer here I thought I would die and I thought my ac needed fixing because it was so warm in the MH.

Per my RV Mobile Repair guy adding a 'small' portable de-humifider will ""assist"" the AC.

I did this and WHAT A DIFFERENCE!
Where the ac alone on a hot summer Florida day it could not keep my coach cool enough to be comfortable. When I added the 'small' de-humidier it allowed the AC to drop the temp inside by almost 20 degrees.

I'm a believer, it DOES work!
fla-gypsy
Explorer
May 13, 2016
I never run a dehumidifier and never had a problem. I think this issue is overstated. A properly sized AC working correctly is plenty

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