AC not cool enough

[aldickerson]

I have a new 2017 Allegro 31sa and have only been in campgrounds without shade. The coach heats up quickly and with the thermostat set at 65 deg. the temp inside still climbs to 87 - 88. Is this common without shade? I have two 13,500 units in the coach.

[Indy54]

If your coach has a separate control in the bedroom for the rear A/C, make sure it's turned to "cool". Otherwise, no, what you describe is not normal. Are you getting cold air from the vents?

[hohenwald48]

Originally Posted by aldickerson

I have a new 2017 Allegro 31sa and have only been in campgrounds without shade. The coach heats up quickly and with the thermostat set at 65 deg. the temp inside still climbs to 87 - 88. Is this common without shade? I have two 13,500 units in the coach.

Short answer is "no" it's not normal. I have a 2007 32' National Surfside with (2) 13,500BTU air conditioners and I can get it about as cold as I want. Even without shade.

What kind of thermostat do you have? Might have something set improperly on that. If you could post a pic someone would be able to tell.

[aldickerson]

Yes, I am getting cold air from the vents, but only 1 vent has a good flow of air. The other 2 in the front of the coach seem to have less air flow. The bedroom a/c does a better job, but still reached about 78.

[aldickerson]

I will have to go to the s to rage lot tomorrow and take some pictures. Thanks.

[THenman]

Originally Posted by aldickerson

Yes, I am getting cold air from the vents, but only 1 vent has a good flow of air. The other 2 in the front of the coach seem to have less air flow. The bedroom a/c does a better job, but still reached about 78.

That kind of sounds like duct blockage may be your problem. Note it is just a guess but low air flow kind of points to that.

Tom

[PSOUZA]

Originally Posted by THenman

That kind of sounds like duct blockage may be your problem. Note it is just a guess but low air flow kind of points to that.

Tom

Duct blockage is a possibility, but more likely excessive friction from too small duct work cross section.

Typical air temperature drop from air input thru output coils is 18 to 20 degrees...max. Common to see 3 to 5 degrees temperature increase per 10 feet of duct length.

Temperature drop is not determined by number of Btu's. The volume of cooled air increases with Btu rating. The volume of cooled air, if it is high enough, can overcome the air leakage, and insulation heat leakage, and reduce the interior temperature.

The higher the losses, the higher the room temperature at max cool. Recirculating the air thru the coils can bring the room temperature down to any reasonable level and will be limited only by air and insulation leakage.

Time to make some temperature delta measurements. If the temp drop across the coils is 18 to 20 degrees, the air conditioner is working properly.

The numbers you give us indicates the system is working at the limit and you have too heavy a heat load.

Phil

[jbrv]

Originally Posted by PSOUZA

Typical air temperature drop from air input thru output coils is 18 to 20 degrees...max. Common to see 3 to 5 degrees temperature increase per 10 feet of duct length.


Time to make some temperature delta measurements. If the temp drop across the coils is 18 to 20 degrees, the air conditioner is working properly.

The numbers you give us indicates the system is working at the limit and you have too heavy a heat load.

Phil

This is what i have been told by more than a few well qualified ac folks.
15 degree cooler from the outside temp is about right. Dark color paint and in the sun and it is 93 outside? good luck getting and keeping it below 80. Most ac's are gonna run at least 80% of the daylight hours to get it there. They just do not have the insulation needed to keep cooler temps without running the ac into a very early death.

[luvlabs]

First off, your windshield and front glass are a giant solar heater. Get yourself an external windshield cover or get some Reflectix and make yourself an internal sun shade.

If it is humid where you are, do not set the thermostat too low. IF you set it to 65 and it is humid, you will form a large chunk of ice inside the A/C and block airflow. So set it to 75 and set the fan to ON. You will have maximum airflow and it will feel and be cooler inside. Set both A/C units the same.

[tom chelbana]

Once a year we take the AC covers off and blow all kinds of foreign items from condenser and the rest of the unit. Found a bird nest in back unit couple years ago. Have watched service working on AC units and pulling cover of and clean condenser one of the first things they do when someone having a problem.