Community Forums

Deepsea · 08-13-2017, 09:09 AM

I am living in my 2013 Canyon Star full time and I can't figure out why my A/C is at 70 degrees but my humidity level is at 84% right now. It seems like the A/C is blowing out moist air?? I have had times where it is at below 60% but this morning I can't get it it drop. I've opened the vents and turned on the fans for a while to no avail. It's 73 outside and very humid. Rained last night. I read that you should lower the A/C temp but that doesn't seem to be working.

luvlabs · 08-13-2017, 09:37 AM

It's really easy to freeze up the evaporator coil when you get conditions like you describe. Best bet is to set the fan speed on high, turn the A/C to off, and let the fan run for an hour or so. Restart the A/C, set it for normal room temp, and leave the fan on high. Oh, and stop looking at the humidity gauge - the weather will change in a few days and dry out things.

Deep Water D · 08-13-2017, 09:50 AM

Despite what you read on the internet and in RV magazines, a properly working A/C is NOT going to freeze up. An A/C uses considerably more of its cooling capacity to remove moisture than to cool the air, hence the higher the humidity in the coach, the fewer BTU's available to cool the coach. By opening your vents and running your fans, you are introducing a lot of moisture into the coach. My advice would be to close up the coach and allow the A/C to run to get the moisture out. I run a dehumidifier in the summertime to keep the humidity down, and allow the A/C's to use more of their capacity to cool rather than dehumidify. Wintertime is a different story, then you need to ventilate to remove moisture. But when the A/C is running, opening events and fans will just compound your problem.

lrsses · 08-13-2017, 09:59 AM

I also use a portable dehumidifier to help keep moisture down and I use it when the RV is parked at home.

Mudfrog · 08-13-2017, 11:05 AM

Quote:

Despite what you read on the internet and in RV magazines, a properly working A/C is NOT going to freeze up.

Under the right conditions, a properly working air conditioner's evaporator coil can freeze up. Friends and us were up in Colorado one year in two separate RVs. We took off for the day to do some 4 wheeling and made it back that afternoon only to discover that our air conditioners weren't discharging any air. Both his and mine had frozen evap coils. Thankfully, the units worked perfectly at our next destination and then, happily ever after.

To the OP, make sure the evaporator drain pan is draining properly and check for dirt/scum/algae on the coil itself.

Deep Water D · 08-13-2017, 11:25 AM

Quote:

Originally Posted by Mudfrog

Under the right conditions, a properly working air conditioner's evaporator coil can freeze up.

What conditions are those, exactly?

Mudfrog · 08-13-2017, 02:32 PM

Quote:

Originally Posted by Deep Water D

What conditions are those, exactly?

Don't remember the exact altitude, gonna say around the 5000 foot mark. But i do remember that our rigs were parked in direct sunlight, temperature close to 80°F, with low humidity.

Got to thinking about it and have to say that our coils didn't have the solid ice build up. Both coils had a layer of white frost on them, across the whole coil, that blocked air flow. Turning the compressor off and leaving the fan on dissipated the frost fairly quickly. So no, it wasn't exactly "froze up".

Deep Water D · 08-13-2017, 03:06 PM

5000 feet would only have a minimal effect on airflow, and none on the refrigeration system. If the coils and air filters were clean, there shouldn't have been any frost buildup at all. Especially if it was 80 degrees outside. My guess is either the coils or filters in both rigs were not clean. I've done HVAC since 1994, and have never seen an iced up coil in a system that didn't have a problem.

Mudfrog · 08-13-2017, 06:51 PM

Quote:

Originally Posted by Deep Water D

5000 feet would only have a minimal effect on airflow, and none on the refrigeration system. If the coils and air filters were clean, there shouldn't have been any frost buildup at all. Especially if it was 80 degrees outside. My guess is either the coils or filters in both rigs were not clean. I've done HVAC since 1994, and have never seen an iced up coil in a system that didn't have a problem.

Believe me, i know what you're saying about air flow restriction. On ours, this only happened that one time and neither of us had any problems with the units, even years afterwards.