Condensation from AC

[hikerainorshine]

Window AC with powered 60 CFM exhaust

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Hi, I installed a window AC unit with the outside part hanging in my galley. I built a box over the back about 3" deep and ducted it to a 6" powered exhaust fan which turns on with a thermostat. I also have a 6" fresh air intake. Before I make it look pretty and try to hide the exhaust pipe, I want to add a drain for condensation, but so far during my test runs (4 hours in 90 degree heat direct sun) I have not seen any water. For now I have a cookie sheet pan under just in case. Is this because the unit only runs for a few minutes at a time, not giving it enough time to remove humidity? Is this a problem? Should I bother installing a condensate pan and drane? Maybe my added exhaust fan has the added benefit of sucking out any moisture/condensation? The temp inside is around 72 degrees and feels fine, very hot and humid outside(Georgia). Thanks for any help or suggestions!

[lrrowe]

That you have no condensation is interesting. I remounted my unit recently and also have no condensation. I too put an aluminum pan under it and it remains dry. It has me baffled.

[Camp4Life]

Some newer systems don't require a drain. The water is collected and then either evaporated or misted out the exhaust. If you check the inside of your exhaust system that you built, you might find the inside is damp or even a little wet. Portable AC systems (Room aircons) that just have an intake/exhaust fan that run out of a window used to have a pan that needed to be emptied, but many models now don't require emptying as the water is evaporated out the exhaust hose.

I would however be careful because a window-mounted model like yours are meant to be stationary. There could very well be a tray with water in it that gets evaporated, but when you shut off your system, some might remain in the tray. Once you start moving your trailer it'll slosh around and might get everywhere if the collection tray isn't a sealed unit.

[lrrowe]

My unit is not new. And when I used it as a "hacked"AC, with it sitting on the ground, there was water dripping from everywhere....unit itself and insulated ducts.

[steve cowan]

Depends on how humid the air is.I spent a week on the South Carolina coast with very high humidity and the unit was dripping out 4 gallons of condensate per day.Under less humid times maybe a gallon per day.









i

[jasstack]

I would be sure and allow for condensation. I would recommend a drip pan, preferably with a drain to the outside (typically under the trailer). Or, you could do a traditional installation of the AC unit as I did, letting it drain outside as if it was mounted in a window in your house. If you have no condensation, that's great, but, if there is condensation, you don't want that water running where it shouldn't. Be prepared for all possibilities. I fired up my AC the other day and the condensation was almost running out the bottom of the unit. Granted, it was very humid (I live in SW Ohio where it can be 90% humidity for days), but I was glad I provided for the condensation drainage!

I've attached a couple photos of my AC installation. The unit is mounted on full-extension drawer slides. They are mounted in reverse of the typical usage, in that I push the unit out when parked and pull it inside when we break camp and hit the road. There is a door on the outside that seals the opening.

AC unit on inside of trailer. The outside door seals it from the elements when traveling.

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AC unit pushed out from inside the trailer. There will be a top-hinged door that will close when the unit is pulled inside the trailer.

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[hikerainorshine]

funny Bob, when I installed my old window until on the garage floor with duct running in and out of the teardrop windows, there was water everywhere. Now that I have it in the galley with powered exhaust, there is no water. We probably have 60% or higher humidity. For those who have lots of water, how long is your unit running before shutting off? Mine only runs for 3-4 minutes.

[Cosmo]

Is the low condensation due to the small cubic feet of air space in the trailer has less air to dehumidify?
If its really dry and the A/C at home is dry I add water which lowers the air temp coming out of the A/C as much as 10 deg. measured at the grill.

Thanks
-Cosmo

[Shadow Catcher]

The "original" hacked Frigidaire was a slinger, condensate dispersed by the fan. a very annoying sound, so I drilled a drain hole. Camping this summer has been hot and humid and there is a good deal of drainage and condensation from the cold hose.

[bbrider]

I would be sure and allow for condensation. I would recommend a drip pan, preferably with a drain to the outside (typically under the trailer). Or, you could do a traditional installation of the AC unit as I did, letting it drain outside as if it was mounted in a window in your house. If you have no condensation, that's great, but, if there is condensation, you don't want that water running where it shouldn't. Be prepared for all possibilities. I fired up my AC the other day and the condensation was almost running out the bottom of the unit. Granted, it was very humid (I live in SW Ohio where it can be 90% humidity for days), but I was glad I provided for the condensation drainage!

I've attached a couple photos of my AC installation. The unit is mounted on full-extension drawer slides. They are mounted in reverse of the typical usage, in that I push the unit out when parked and pull it inside when we break camp and hit the road. There is a door on the outside that seals the opening.

49c small.jpg

49a small.jpg

This is what I was thinking I would do with my AC in my Wee-Go. I had planned on adding aluminum angle around the AC unit where the clips are to seal it when it is pushed out on the top and both sides. I just can't figure how to make a seal for the bottom side of the ac unit. I also thought the door would fit inside the opening when closed. How does your door seal the opening when it is closed?

[jasstack]

The door seals with D-profile-shaped door seal and stays closed with a simple lock. There are several different sizes of seal available. The seal is applied to the door stop. In addition to putting aluminum around the AC unit, I added one to the front bottom of the unit. This seal rubs lightly on the shelf. It isn't perfect and I will probably redo it a some point. I've attached a photo of a sample of a door seal.


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[bbrider]

The door seals with D-profile-shaped door seal and stays closed with a simple lock. There are several different sizes of seal available. The seal is applied to the door stop. In addition to putting aluminum around the AC unit, I added one to the front bottom of the unit. This seal rubs lightly on the shelf. It isn't perfect and I will probably redo it a some point. I've attached a photo of a sample of a door seal.


Sent from my iPad using Tapatalk

Thanks! I was thinking of making the whole shelf for the ac slide out with the ac unit so the bottom seal would be mounted to the shelf. Then I thought if I used a T aluminum around the opening the shelf could pivot down and actually sit down on the T to make the bottom seal....LOL. Decisions decisions. I would be interested in seeing a picture of the door if you have any.

[m.colley]

funny Bob, when I installed my old window until on the garage floor with duct running in and out of the teardrop windows, there was water everywhere. Now that I have it in the galley with powered exhaust, there is no water. We probably have 60% or higher humidity. For those who have lots of water, how long is your unit running before shutting off? Mine only runs for 3-4 minutes.

This might be the problem. Your unit might be doing what we in the AC industry refer to as "short cycling". On the garage floor you have a much bigger space to cool and the unit runs normally, removing moisture from the air as it reaches its thermostat temp. In small spaces (like a small 4x8 TD) the AC unit reaches its Thermostat temp before it removes the moisture in the air. In the industry we call this "satisfying sensible temp before latent temp" or short cycling. AC units are meant and designed to remove moisture and latent heat from the air before reaching there temperature set point/tstat setting.

There are cures for this problem if this is whats going on.


Martin