Hi Ryan~

Did you mean "VCP"10K ?…I'm not familiar with "PVC" models…

If you have good airflow (low airflow causes icing) then it seems you may have lost refrigerant…But where did it go ?

These units are all solder connections, and are not supposed to leak like you might expect of auto A/C with rubber hoses & compressor shaft seals…

Rotary compressors (such as in the self contained units) do normally run hot…But do need refrigerant return to keep from burning up…

Short of testing with gauges to read pressures the only test you could do is with a thermometer…Read temp at the return air grill…Then read it at the closest discharge grill…We are looking for 15 to 18 degrees difference (TD)

If less than 15 degrees I'd say get the unit serviced (and checked for leaks) don't run it low on freon as it will burn itself up…

If it's more than 18 degrees…Look for air restriction…Both return & discharge…

Steve~

Post edited 11:03 am – July 14, 2011 by Steve Pooler

Don't think I have ever shot a rotary with a temp gun…Just know that the outside can/shell is in contact with the hot discharge gas with rotary compressors (it's part of the design) So it can also change related to head pressure…

All Marine Air units till 2010 used R-22…

Also remember that infrared temp guns only sense surface temp…Not air temp…So the surface would have to be the same temp as the air passing across it, and there could be some delay in it getting there, also differing thickness/materials change temps at differing rates…

Steve~

One thermometer is better, as I can never find two that read the same…

Put em side by side where ever & they always seem a couple degrees different…

This could make you think you have a 15 degree TD when in fact it's like 13….Or vise verse 

Steve~

Post edited 11:33 pm – July 14, 2011 by biohazard

I ran some tests on the boat.  We ended up pulling the a/c unit out and cleaning it all out.  There were a few mashed fins, I straighented them best I could.  I seem to have goten a bit more air flow now but not much.  

The temp after this on the grill inlet was around 72-74.  Temp on the nearest outlet was 50-52.  Water temp is around 78-82 degrees.  Ambient temp was around 75, with 70% humidity.  

The suction line was still getting cold, the other line was getting hot.  The suction line was building condensation also, but it did not freeze.  The air fins felt cool and had good air flow in front of them.  

Tomorrow it will be 90 degrees and I will be able to give the unit a little better test.

Here is a picture of my bent fins

Hey Steve,

The duct work has multiple sized and junction boxes.  I will take measurements and get some pictures tonight.  I will also remove the unit from the ducting and re-direct it.  I will post results and pics when I get home.