RV Airconditioner


New Member
With spring/summer coming on and our plans to travel the hot Southwest USA, I need to see if my two 13,500 DuoTherms are operating up to par. Any suggestions on self checks I can perform to test my units. Any internet sites with info? Thanks!

Gary B

Senior Member
RV Airconditioner

Hi genel, yes you can test them yourself, it easy, about all you need is a thermometer, I like the indoor/outdoor digital type you can purchase at wal-mart etc. check the themp inside the coach & record it then run one of the ac's put the temp probe in the ac' air outlet and wait to see what the final temp differnece is, a good ac will/should have a temp drop of 30*F if its more say 40*F its in excellent condition, if is less than 20*F then you may want to have it checked. Good luck. :) :laugh: :cool: :bleh: :approve:


Senior Member
RV Airconditioner

Actually, my RV service manual says that the temperature differential between inlet air and outlet should be about 18 degrees. One thing to check before you pay for service is to make sure that the coils of the A/C unit are clean and free of obstructions. Also if there are many bent fins, get a comb that is made for the job and use it to streighten them.


Senior Member
RV Airconditioner

I believe the most important check that can be made is the inside filters.......replace them before you fire the A/C up. If they are the least bit dirty/clogged you won't get good cooling. Secondly, make sure the fins on the top unit are clear and not bent. :cool:

C Nash

Senior Member
RV Airconditioner

Agree with kirk & Gary on the temp difference. Most ac's will lower around 15 degree from air entering the unit so if you are recirculating the inside air as it gets cooler with each pass through it would eventually get to the 30 or so degree below what the OUTSIDE temp is as Gary said.
RV Airconditioner

I spent over 15 years in the A/C business and what I'm about to say applies to any electric A/C unit.
The temperature difference you get across the evaporator will vary indirectly to the relative humidity. The more humid the air is, the more effort the A/C puts into drying it. Once the air is dry, the temperature will start to drop.
Let the unit run for at least 5 minutes with the indoor temperature above 75 degrees. If the evaporator coil is accessable, look for a full pattern of sweat on the coil. Ideally, it should go back to the compressor. Frost is bad. It means that the air entering the unit is too cool, the air flow is restricted (usually dirt), or a real problem.
Archer is dead on about the filters. As with any type of refrigeratoin unit the best thing you can do is to KEEP IT CLEAN.
It should go without saying, but don't put you hands mear moving parts or live electrical connections...if you're not sure, pull the plug and wail until everything has stopped first.
Check your onwer's manual to see if the fan motor needs oil. Most don't, but some may. The manual is also the best place to find out how to remove the cover for cleaning with doing damage.