Evaporative cooling

[Off Rez]

I had an idea, and since I'm usually "late to the party" many of you already know this, and my ideas are almost NEVER original, I decided to try spraying water on the roof of the TT during the hot part of the day to help the AC cool the TT. Well, the results are in but first a little more info on our science experiment.

We have a 33' TT with 1 15k AC unit, ducted through the ceiling. The outside temp at the time was about 102 with a relative humidity of about 10%. Inside temp was 84. There was no shade, full sun. I don't know what the temp of the water coming out of the hose was as I had no way to gauge it but I would call it "tepid". Ok, that's the setup.

I sprayed the roof with what I would call a good soaking until the drain spouts were pouring continuously. Then I went inside to record the results. I know, I'm a nerd.

The kids an I observed that the internal temp of the trailer as measured by a new digital thermometer dropped from 84 to 77! I was amazed! I didn't think it would be that effective. The resulting temp drop lasted for maybe 30 minutes is all, however. It would take multiple soakings to get through really hot afternoons but maybe enough to give your AC a rest.

We tried an hour later but the sun was going down and you could see that the droplets were not evaporating very quickly. No evaporation, no cooling and we saw the temp drop only 2 degrees.

Give it a try and see if it works for you! Cheers!

[Sharon455]

I cannot imagine a campground not having a problem with this as most don't allow you to wash your rig. However, we are also in Arizona and might give it a try to cool things down if we have someone using the RV as a guesthouse.

[MR.M]

Originally Posted by Off Rez

I had an idea, and since I'm usually "late to the party" many of you already know this, and my ideas are almost NEVER original, I decided to try spraying water on the roof of the TT during the hot part of the day to help the AC cool the TT. Well, the results are in but first a little more info on our science experiment.

We have a 33' TT with 1 15k AC unit, ducted through the ceiling. The outside temp at the time was about 102 with a relative humidity of about 10%. Inside temp was 84. There was no shade, full sun. I don't know what the temp of the water coming out of the hose was as I had no way to gauge it but I would call it "tepid". Ok, that's the setup.

I sprayed the roof with what I would call a good soaking until the drain spouts were pouring continuously. Then I went inside to record the results. I know, I'm a nerd.

The kids an I observed that the internal temp of the trailer as measured by a new digital thermometer dropped from 84 to 77! I was amazed! I didn't think it would be that effective. The resulting temp drop lasted for maybe 30 minutes is all, however. It would take multiple soakings to get through really hot afternoons but maybe enough to give your AC a rest.

We tried an hour later but the sun was going down and you could see that the droplets were not evaporating very quickly. No evaporation, no cooling and we saw the temp drop only 2 degrees.

Give it a try and see if it works for you! Cheers!

They have misting systems you can put together to mist water over the unit all day for a reduction in temps of about 30 degrees depending on water temp and shade . would be easy to install with an automatic timer . very common out west where there is low humidity

[Scrapper]

Originally Posted by Sharon455

I cannot imagine a campground not having a problem with this as most don't allow you to wash your rig. However, we are also in Arizona and might give it a try to cool things down if we have someone using the RV as a guesthouse.

Campgrounds with seasonal sites allow washing Monday thru Thursday only. If you are traveling and just spending two or three nights you might get away with it.

[MR.M]

I have never been at a seasonal site that does not allow washing rv or trucks from Florida to Montana to Colorado . i would think AZ would be stricter since they do not have much water to begin with. so each park , each place is different and is not the same across the board . Edited to add that a good misting system uses small amount of water few gallons a day compared to letting a hose run

[Reverse_snowbird]

10% relative humidity? You probably need a humidifier. That's why they use evaporative coolers in Arizona rather than air conditioning.