air condition vs humidity

Actually, I purchased the AC at lowes. The salesman told me that he had just done the same thing and a 5K btu unit did not cool his van when the outside temps reached 90+ degrees. At the time I felt lucky that I ran into him. Oh well

You have a very small space and the A/C you have is made to cool a large room - in some homes more than one room. I am not sure why someone told you the 5K BTU would be too small. You may also find that the A/C that you have will start to freeze up when you still need it to be running inside. You might want to just switch to the smaller A/C.

I heard about the small heater trick and got one right away. It "did" reduce the humidity to a very comfortable 45 percent. However, the AC continued to run and the temp went down to 55 degrees (thermostat set to 72). Either sweat to death or freeze. Tried AC on high and low speed. No difference

A small 300-750 watt heater makes sense. I've also been known to run the A/C, fire up the propane furnace (the wet air exhausts outside, so it doesn't change the humidity), and alternate until the air is dry enough to be comfortable.

Does the A/C unit have a fan control?

If it does...run it on 'Low Speed'. That will allow longer cycles to cool air and help drop humidity.
BUT that is just a band-aid fix.

Your van is too small.......:B

Sounds crazy but try running a small heater on low to give some false heat and will assist with humidity removal. Opening the window just makes matters worse.

Bumpyroad wrote:
yep, you might have too big a one and it keeps shutting down. needs to be running more or less constantly to take out humidity. that is why they size them to fit houses, etc.
bumpy

X2 - sizing A/C's is another area where bigger is not always better or more is better than less.

Your A/c is probably too large for your unit and it shuts down more frequently than it should.

dsmythe wrote:
I installed an 8000 BTU window AC in a Chevy 1500 express ... The AC cooled the van just fine but the humidity was way high (over 80 percent).
Don Smythe

I got a used 7K btu LG portable to deal with temps over 90 when my roof top on my van wasnt keeping up (in direct sun). It stands in the van with the exhaust hose out one of the little sliding windows. I tried to use it as often as possible in conjunction with my overhead AC (when I had adequate amperage). The water streams out of the overhead to the outside, but the LG inside is not plumbed to get rid of water so I run it without the dehumidifying function. That, and a small clamp on fan directed right at me seemed to keep me and my dogs cool enough. I did notice that just when I stopped after driving the van would really start heating up and I eventually figured I needed to open the hood to let the engine cool off. I also put up material between the drivers compartment and the rest of the van to limit the heat from the engine and the front windows. Now all I have to do is figure out how to keep my van heated since the overhead doesnt keep up with that either when temps drop below 40. I did get some insulation and will try that.

When I installed a roof mounted ac on a sprinter I also was given wrong info and went to large.
The only cure I could find was to leave both door windows open about 4 inches so the ac could get max
airflow thru the unit. This helped but it never worked properly. Good luck

yep, you might have too big a one and it keeps shutting down. needs to be running more or less constantly to take out humidity. that is why they size them to fit houses, etc.
bumpy