AC Undersized

[wiredgeorge]

Originally Posted by rlh1957

You’ll find that real cooling difference won't be felt to the amount you’re wanting with those air re-directors.
They can’t increase the cooling capacity .
In 95+ degrees especially high humidity even a 15K unit can't keep up. Fans around rig can help some.
Two AC’s sometime struggle to cool it down.

Bet you haven't installed one of the RV Airflow gizmos or used one. While it can't make a unit get colder than its design restrictions it does up the volume of cold airflow out the vents by quite a bit and this in turn makes the thermometer in my camper show cooler inside temps. We usually use a 2nd 14K BTU portable as an adjunct to our 15K BTU roof Brisk II in temps over 90F but this last time out the portable wasn't needed and we kept the cabin temps just over 70F in mid-90F out temps in direct sun. I attribute that to the RV Airflow. A BIG improvement over operation without the thing in place.

[mjsibe]

See attached
AIR conditioners can only do approximately 20° difference.
@90° outside air Best it can do is around 70°
@100° around 80°
And so on.

[Steveo57]

Originally Posted by mjsibe

See attached
AIR conditioners can only do approximately 20° difference.
@90° outside air Best it can do is around 70°
@100° around 80°
And so on.

That must be news to the millions of people who live in areas with 100+ degree temps during the summer who are all enjoying their 70 degree air conditioned homes and businesses.....

[rhagfo]

Sounds like you need a dehumidifier before additional AC, that much moisture you are lucky your AC hasn’t iced up.

[JRTJH]

Originally Posted by mjsibe

See attached
AIR conditioners can only do approximately 20° difference.
@90° outside air Best it can do is around 70°
@100° around 80°
And so on.

Whoever "wrote" that article for Google has no idea what they're talking about.

Air conditioners DO NOT operate on a 20 degree differential based on OUTSIDE air... They function and are measured based on AMBIENT air... Ambient air is the differential between "air going into the air conditioner return grill" and "air flowing out of the discharge vents"... In other words, the differential is based on INTERIOR air temperatures (ambient air) all measured INSIDE the RV.

If the inside of your RV is 90F, then the air going into your A/C return vent is 90F and the air flowing out of the discharge vents "should be 20 degrees cooler" (minimum). That too, is based on the length of the duct run, the insulation around the duct and the velocity of airflow.

As the trailer "cools off" the air going into the A/C return air grill will be cooler and the discharge air temperature will also be cooler. When the interior of the trailer is lowered to 80F, then the discharge air at the vents "should be" closer to 60F. Once the trailer cools to near the thermostat setting, there should be "about a 20 degree difference" between the ambient air (that's the air around the air conditioner return air filter) and the discharge air outlets in the ceiling.

If you think about what that "google expert" explained, it would be impossible for any building in Las Vegas to be cooler than 100F when the "outside air temperature" is 120F, which is a common condition in Las Vegas in July/August.....

So, don't believe everything Google tells you, they're as "full of dressing as the Thanksgiving turkey".....