Are my A/C's working correctly?

[rickydennis01]

I have a 2018 Fleetwood Pace Arrow 38N with 2 13,500 BTU A/C's. The RV is a little over 39 ft. I am new to RV'ing and don't really know what to expect concerning the cooling capacity of these units. I have heard they should be able to keep the coach 20 degrees cooler than the outside temperature. Back in July, we were at the Outer Banks and it was hot. The outside temperature was 91 degrees. The inside temperature according to the display reading was Zone 1 95 degrees and Zone 2 88 degrees. I know that these readings were incorrect and that the interior of the coach though uncomfortable was not that hot, but I did not have separate thermometers to verify the actual coach temperature.
A few weeks later during a service call, I had the dealer check the A/C units and they said they were working fine.
I was not convinced, so this past week I decided to run a test. I had the thermostat set at 75 degrees for both Zone 1 and Zone 2. Over the last few days, I have registered the following results with the RV closed (entered only to check temp) and all shades pulled. I was using separate thermometers for each zone as I know for sure I can't trust the temp reading on the display panel.
1) Outside temp 84; Zone 1 77; Zone 2 75
2) Outside temp 88; Zone 1 77; Zone 2 75
3) Outside temp 83; Zone 1 75; Zone 2 75
4) Outside temp 87; Zone 1 80; Zone 2 79
5) Outside temp 85; Zone 1 76; Zone 2 76
6) Outside temp 90; Zone 1 82; Zone 2 80
7) Outside temp 89; Zone 1 79; Zone 2 78
😎 Outside temp 90; Zone 1 81; Zone 2 75
I am concerned that there were several instances where the A/C's were not able to maintain the 75 degree setting even with the RV completely closed up and no one going in and out the door. I have, again had the dealer check the A/C's and am being told that they are functioning correctly. I contacted Fleetwood with questions about the cooling capacity and they were absolutely no help.
My question,am I expecting too much from these A/C's and is this pretty typical or do I have an A/C issue that is going to make camping unpleasant when the weather turns hot again?
Thank you all in advance for any comments you may have.

[Old-Biscuit]

18-20*F DIFFERENCE between Air Return (at filter) and AIr DIscharge (at plenum) is best that an A/C Unit can do

TWO 13.5K btu units and 39' RV is going to be marginal ....should be Two 15K btu

[DutchmenSport]

You need to check the temperature right where it blows out of the air conditioner, NOT where the thermostat is. You may find the air blowing at the air conditioner is 65 degrees, but 5 feet away it could be 75 degrees and 10 feet away it could be 85 degrees.

There are many factors that would cause the camper to be so hot and why it appears the air conditioner is not keeping up: the size of the room, the insulation value in the walls and ceiling, single pane windows, how well the slide out seal, and outside temperature. It's not that the air conditioner isn't blowing cold, it's just trying to cool too much hot.

So, check the temperature right at the closest place the air blows out of the air conditioner.

There could be other factors too why it's not keeping up with the space to cool. Sometimes air ducts are not installed properly in the trailer roof. Sometimes there is an ice build up on the coils on the roof. Sometimes there is a blockage of dust and dirt on the coils.

[Cocky_Camper]

We have a 35ft class A with a 15k and 13.5k btu. Both can keep it 69* with no problem when it was close to 100 outside and humid during July. We do use reflectix material in the windows and added a thermal curtain behind the front curtain. But it cools without a problem.

Now it may take it all day into the night to get to that temperature when we first set up, but it maintains it once it gets there.

And I was told by our A/C guy that the A/C should cool the air 20* cooler than the return air, not the exterior air temperature.