Originally Posted by GaryG
Eric, i've got an issue. Ac runs blowing cool air for about 10 mins and then starts blowing warm air. Brand new unit. I thought it wasn't getting enough outside air so I stuck a 35 cfm computer fan on the intake hole. Still doing the same thing. It's 85 degrees an d 45% humidity here, so I don't think it's too hot or too humid. Also my unit is a remote control unit, but, I don't think that matters. I'm about to pull it out and stick it in a window to see if it's my installation or the unit itself. Any thoughts on this? Thanks, Gary
Gary, hopefully others will chime in with their thoughts as well. I will give a couple of my thoughts and I apologize up front if they are a little obvious, but sometimes those are the missing piece of information.
First, it could be that the AC thinks it is cool enough and turns off. I assume with the warm air you hear the compressor turn off. It could be working normally. We had this when we didn't have a fan redistributing the air in the trailer. It would get cold by the floor and then stop running even though it was hot at the top of the trailer. Your AC may have different modes as well (low, high, max, no energy saver...?) and that may effect things as well.
Second, the compressor could be overheating and shutting down. It could be due to something like the temperature sensor touching the coils, coils icing, or the AC wanting to check room temperature, but most likely it is due to lack of air flow.
Third, (similar to second) another guess is that you didn't seal well enough around the lower cabinet the AC sits in and trailer air is being sucked through the AC so hot air from the outside comes in the trailer making the AC work all the harder and causing a compressor shut down.
Before you take it out, I would try and check the amount of flow of air going in and out and the temperature of the air going in and out. (A battery
operated remote temperature sensor is best but your hand is better than nothing. While you are at it, check the actual temperature in the air flow out of the AC and at the top of the trailer. Actual numbers help people on the forum since "warm" is a pretty vague concept.) The air flow/temperature check should also catch obvious issues, like if you have the flapper valves installed backwards blocking air flow in or out. The air on the exhaust should be pretty warm/hot and feel like a lot of air. Remember you usually have a couple of square feet of air flow on the back of the AC and now we have to get the same amount of air through a small hole. Make sure your blower is on high speed.
I agree with taking it out and seeing how it runs. If it runs fine, while it is out you might cover up a good portion of the back and see if it duplicates your problem indicating lack of air flow.
I did use a 4" blower instead of 3" which is ~75% more area and a bigger fan so that is my first guess. (even though I thought a 4" fan was overkill)
Totally unrelated, while it is out, make sure water is coming out the AC only where you want it to be coming out. You can just run this in your drive way. I just put it on a couple of saw horses so I could see what the water is doing.
Good luck and let us know what you find.