AC doesn't seem to cool like it should

[Sdexte]

Hello, 2019 Montana HC 373RD with Dometic Brisk Air II w/heat pump, 15,000BTU. Was working great until we had a recent roof replacement and they removed and replaced the unit. Now it does not seem to cool the living room and kitchen down like it used to. The outside temps are running in the low to mid 90's and the best we seem to be able to get the inside temp down to is 80 degrees ( I have the thermostat set at 65 degrees). I removed the round louvered AC vent covers and there is a strong air flow coming out. I'm trying to think of what they could have done to the unit, or something that they should have done but didn't, that would have made the difference between then and now. We have been in very warm weather in the past and it kept it very cool.
The bedroom AC unit, which was also removed and replaced, seems to be working correctly and keeps the bedroom nice and cool. Any suggestions before I call a tech would be appreciated.

[DutchmenSport]

You need to put a thermometer directly at the vent where the cold air blows into the camper. If that is right at the air conditioner, or a roof vent, check the temperature there.

On mine, the current temperature blowing out of the air conditioner vent is 42 degrees. yet the cabinet doors in the kitchen are 71. The floor is 74, and the wall (in the kitchen is 76). The outside temperature at this moment is 80 degrees and the sun is going down.

There's nothing wrong with the air conditioner. It's blowing cold. The problem is with the rest of the trailer. Thin insulation, gaps in the slide seals, opening and closing doors, electronics running inside the camper, and the air conditioner is simply not able to keep up with the all heat that is intruding. Windows with sun shining in allow a lot of heat to transition in. There is simply too much heat to too much space for the air conditioners to keep the inside temperature 42 degrees. Impossible.

So, get an infared thermometer so you can "shoot" the temperature on any surface. You can shoot the infared directly into the air duct and get the temperature of air actually coming from the air conditioner. Click here. Also, these thermometers are wonderful for checking the temperature of your tires, your brakes, the water temperature at the faucet, even the temperature of the surface of the road you are driving on. I've have, like 5 of them. I keep one in the camper all the time and one in the truck all the time.

[Ram Montana High Country]

Originally Posted by DutchmenSport

You need to put a thermometer directly at the vent where the cold air blows into the camper. If that is right at the air conditioner, or a roof vent, check the temperature there.

On mine, the current temperature blowing out of the air conditioner vent is 42 degrees. yet the cabinet doors in the kitchen are 71. The floor is 74, and the wall (in the kitchen is 76). The outside temperature at this moment is 80 degrees and the sun is going down.

There's nothing wrong with the air conditioner. It's blowing cold. The problem is with the rest of the trailer. Thin insulation, gaps in the slide seals, opening and closing doors, electronics running inside the camper, and the air conditioner is simply not able to keep up with the all heat that is intruding. Windows with sun shining in allow a lot of heat to transition in. There is simply too much heat to too much space for the air conditioners to keep the inside temperature 42 degrees. Impossible.

So, get an infared thermometer so you can "shoot" the temperature on any surface. You can shoot the infared directly into the air duct and get the temperature of air actually coming from the air conditioner. Click here. Also, these thermometers are wonderful for checking the temperature of your tires, your brakes, the water temperature at the faucet, even the temperature of the surface of the road you are driving on. I've have, like 5 of them. I keep one in the camper all the time and one in the truck all the time.

The original OP indicated it worked fine before roof replacement.

[Ram Montana High Country]

ScottZ had a recent post indicating on his unit from the factory misaligned the unit to the holes thru roof. If the misalignment allows air leakage between air return and air output all kinds of issues can develop. IMHO, I'd start with pulling AC and check alignment using mounting holes as reference point. Also make sure there are no leaks around coils in unit on the foam covering them.

[MARK A]

More than likely they smashed the return ducting or the supply ductwork stomping around up there.


Mark