Keystone Sprinter Not Cooling

[cfensty]

I recently bought a Keystone Sprinter 353FWDEN. This is my first fifth wheel, although I have owned several travel trailers over the past 30 year. One problem I am experiencing is that the AC is not properly cooling the inside. During a recent camping trip, the outside temp was 85 degrees but the inside would not cool lower than 78 degrees. I took the camper back to the dealer and the dealer replaced and installed a completely new AC unit. This past weekend the temp outside soared to 95, and the inside temp was no lower than 85 degrees.

I've had some people tell me that fifth wheel trailers are harder to cool because of the higher ceiling and additional room space. Is this true or do I still have an air conditioner issue?

[wingnut60]

You have only one AC? If so, that is the problem. Too much space, too little AC capacity.
A properly operating AC unit will only cool incoming air about 20d--you need to get a temp gauge and check air coming out of the vent, should be about 18d cooler than near the intake. However, if this measurement is close to 20d, then the answer is a 2nd AC.
Fivers are not inherently 'harder to cool' but additional room space IS harder to cool--and keep cooled.
Joe