AC temp

TXiceman wrote:

Desert Captain wrote:
If your AC is producing 20 degrees cooler than the ambient (outside), temp it is working just fine.

:C

Wrong. It is not meaningful number compared to outside temperature.

Run the unit(s) on high fan and keep the compressors on for at least 10 minutes. Measure in inlet air temperature and the outlet air temperature as close to the unit as possible. Use a thermometer and not an infrared temperature gun. The infrared will not measure the air temperature, but it will measure the temperature of the grill.

A normally operating RV A/C will have the leaving air temperature 18 to 20 degF lower than the inlet air temperature. Much higher or lower is an indication of a malfunctioning A/C unit.

The most frequent problem with an RV A/C not cooling correctly is low air flow. This is caused by:
-running fan on low speed.
-dirty air filter(s).
-dirty evaporator coil.
-baffle between inlet and outlet not sealed and leaking.
-holes in the installation where the wires enter the RV.

In 90 degF plus weather and especially full sun, one A/C will not cool an RV over about 30'. You need two A/C units and they may not work in a typical entry level in the 90 degF plus temps.

You have to remember that n RV is not nearly as well insulated as a house.

ken

Oh lighten up,my 20 degree differential is NOT wrong, it is a "meaningful" number to me. Trust me if it is 95 outside and my rig is 75 inside my AC IS working just fine... sheesh. :R

Desert Captain wrote:
If your AC is producing 20 degrees cooler than the ambient (outside), temp it is working just fine.

:C

Wrong. It is not meaningful number compared to outside temperature.

Run the unit(s) on high fan and keep the compressors on for at least 10 minutes. Measure in inlet air temperature and the outlet air temperature as close to the unit as possible. Use a thermometer and not an infrared temperature gun. The infrared will not measure the air temperature, but it will measure the temperature of the grill.

A normally operating RV A/C will have the leaving air temperature 18 to 20 degF lower than the inlet air temperature. Much higher or lower is an indication of a malfunctioning A/C unit.

The most frequent problem with an RV A/C not cooling correctly is low air flow. This is caused by:
-running fan on low speed.
-dirty air filter(s).
-dirty evaporator coil.
-baffle between inlet and outlet not sealed and leaking.
-holes in the installation where the wires enter the RV.

In 90 degF plus weather and especially full sun, one A/C will not cool an RV over about 30'. You need two A/C units and they may not work in a typical entry level in the 90 degF plus temps.

You have to remember that n RV is not nearly as well insulated as a house.

ken

It was in the upper 90's yesterday in Prineville Oregon. The inside temp in the RV was 83, the outlet temp at the A/C unit, with the air dump open was 53 degrees measured with a digital probe thermometer.

This is a Dometic 13.5 BTU unit. Parked in full sun, hitting the RV from the passenger side with the awning out.

30' bumper pull Cougar.

CREATO wrote:
At 96 degree in full sunlight I couldn't get below 85 deg inside I am going to check the intake and exhaust numbers next time. I didn't have my infrared temp gun with but I am thinking we are going to add another unit in place of the fantastic fan in the bedroom.

I am assuming it is wired and ducted in the bedroom if so any suggestions on who as the best low profile ac unit.

Can IR Thermometers Measure Air Temperature?
No and yes. No, because air does not emit infrared, the emissivity is too low to be detected. Yes, because you can by pointing the IR thermometer at anything that has the SAME temperature as the air:
Outdoor: leaf, tree, grass (in shade) has the same temperature as the air Indoor: your desk, a piece of paper, has the same temperature as the air.
The key to get "Air temperature" is to measure "anything which should have the same temp as the air."

RoyB wrote:
Our air conditioner works alot better if we are parked under a big ole shade tree...

Roy Ken

And therein lies the answer. As most know by now its almost impossible to create a comfortable temp inside the coach while it is setting in full sun and 100 deg outside. Shade really helps big time..Ita so hot around Primm and Las Vegas Nv we had to park the coach and get a room for the night.The room was nice and cold. It was unlivable in the moho.And the a/c are in top shape.

Our air conditioner works alot better if we are parked under a big ole shade tree...

Roy Ken

20 degrees from the return air, not outside.

Pull the vent off from the ceiling and see if ice is showing on the fins.
chevman

Dometic the same as when new.

chevman

larry barnhart wrote:
The ac will freeze up if you go a lot lower that out side. 15 to 20 degrees is a guess. We did freeze ours and a new GMC when it was 105 in Atlanta and the car was set to 60 degrees. We have replaced our 15000 ac in our alpenlite 2 winters ago.

chevman

What brand did you go with