Portable A/C - "Self-evaporating" question

[tomnshell]

We just returned from High Meadow Campgrounds in Hershey, PA.  Great camp and a great time!  Anyway, it was pretty hot and we had our portable A/C unit running all day.  It is a self-evaporating unit, but has a drain plug in case we need to actually drain it.  The system would blow nice cold air for a while, then warm, then cold, then warm, and so on and so on...  Does the system have to burn off the condensed humidity in the holding tank when it gets too full (run all day on really hot days), resulting in it blowing warm air for awhile?  I was going to measure the drain plug and rig a line outside the camper so it never gets too full.  I just wanted to make sure my assumptions are correct and I'm not wasting my time with this drain line.  Thanks!

 

[jjkz24]

You more than likely are experiencing the compressor of the A/C unit turning on and off, to maintain a constant temperature.  For instance, if you have it set for 70 deg., the compressor will cycle on and off to maintain that temp, hence, feeling cold and not cold air coming from it.

 

[tomnshell]

I can set the temperature via the display, then it returns to displaying the actual temperature and changes as the temperature changes.  Say I had it set to 75 degrees and it reads 80, it still cycles from cold to warm.  Therefore, I don't believe it is cycling to maintain the temperature, since it hasn't reached the desired temperature it is set to.

 

[John From Detroit]

The problem with a self evaporating model is that not only does a regular unit drop the temps, it drops the humidity (That is humidity that is drip, drip, driping onto the ground)

The self contained job.. Returns the humidity to the room, only more so, since the cooler air can not hold as much water. Just so you know (Thus the humidity goes up)

 

[Gary RV_Wizard]

I've never heard of one of those pausing to evaporate water, but ??? 

Another possibility is that it has a freeze sensor on the cooling coil. If the cooler gets near 32 degrees, the compressor shuts off until it warms up again. This is to prevent the a/c from freezing up solid in humid weather.

 

[tomnshell]

That sounds like enough info to convince me to simply run a drain line outdoors.  Thanks for the responses!

 

[Gary RV_Wizard]

If it's a freeze sensor shutting things down, a drain line won't help.  Does the cycling stop if you empty the water sump? Take a turkey baster or similar and suck out a cup of water and see if it stops.

Good luck - let us know if it works.