am I expecting too much?

Thanks for all the ideas, first thing I will measure the output and see if it is at least 16 degrees cooler than the ambient air in the coach. I am parked in the shade now, with a pillow in the fantastic fan vent and getting 11.5 degrees cooler - every little bit helps. I just have to keep it cool from the morning.

Check your ducting as mentioned and check where the air blows straight down. Mine was so poorly sealed that it was sucking cold air right back into the intake from the exhaust. Sealed everything with duct tape and insulation. It was much better after that, not perfect but better.

The difference between the air going into the AC and the air coming out should be 16~21 degree's. The outside temperature has no bearing on it.

wolfe10 wrote:
Measure temperature at the AIR RETURN and at the outlet. Tell us the delta.

That is the only measurement that evaluates A/C performance. The rest relates to insulation, cubic feet of interior,etc.

Ditto

Measure temperature at the AIR RETURN and at the outlet. Tell us the delta.

That is the only measurement that evaluates A/C performance. The rest relates to insulation, cubic feet of interior,etc.

herefishy wrote:
Our 5er will only cool to about 9 degrees less than outside - is that all the rest of you get?? Or do I need another air conditioner?

Simple things first: make sure the ducts are properly connected to the A/C and all of the A/C's output is being properly distributed.

Next realize that a RV with minimal insulation parked in direct sunlight with ambient temperatures 90 degrees plus puts a heat load that any 13,500 BTU or even 15,000 BTU A/C will not overcome. You will need 3 maybe even 4 A/C's to overcome that heat load.

Your one A/C is doing a pretty good job under those circumstances reducing the temps by 9 degrees.

I would say that 9 degrees isn't cutting it. Time for a second unit!!

First you need to discover if the ducting is even connected. Then verify the in vs out is properly separated in the inside plenum. Then get an a/c thermometer to check in vs out temperature. I believe you should have at least 20 degree drop.

Working well I would think you could get 15 to 25 lower than outdoors.

Now if you arrived with a hot RV it may not really cool until an hour after the sun goes down. The next day is the real test. Set the temp at 70 or less at sunup and see how it holds.

I would say mine does closer to 15* below outside temp if I start it early in the day and keep the blinds closed.

My 40' has a15000 BTU as its main A/C and a 13500 in the bedroom. If I run both I can freeze you out of the fiver. The main 15000 keeps up with little problems with temp set at 76°. We always try to pick a shady site, keep the shades down and have vent pillows for two of the roof vents, bath vent is kept open. Have you tried cleaning your filter and coils? If ducted check your vents to make sure to make sure your're getting good airflow. Good luck, travel on.