a/c maintenance ?

[pa-traveler]

hello

this is my second question i have ever posted on this forum, the first proved to very helpfull.

is there any maintenance to be performed on my a/c unit, i have noticed 2 things.

1. a little condensation on the interior side of the of the a/c unit around the vent and also a little around the vent near the door. is this just condensation from the humidty?

2. also when the a/c unit stops running it makes a little rumble and a little thunking sound, is this normal.

thanks for your help.

 

[Karl]

pa-traveler,

2. also when the a/c unit stops running it makes a little rumble and a little thunking sound, is this normal.

There is sometimes a thud or thunking sound when the compressor stops running, and that's normal. That's when the piston loses momentum and encounters the still high pressure at the compressor output. Stops the piston dead in its' tracks.  By rumbling, do you mean gurgling? That could be the high pressure/low pressure sides of the system equalizing the pressure between themselves. Again, normal. That's the reason you can't stop an a/c and immediately restart it. There's a delay to allow the high pressure to return to normal, otherwise the compressor would not be able to start again.

 

[Gary RV_Wizard]

1. a little condensation on the interior side of the of the a/c unit around the vent and also a little around the vent near the door. is this just condensation from the humidty?

Yes, but there could be some cold air leakage around the system that exacerbates the problem. With the air intake grill removed and the system running, feel around the inner edges of the heat exchanger to see if you can detect any cold air blowing back into the intake  area from the output side. This will chill the intake side and cause extra condensation. It can even cause a freeze up on hot humid days. If there is an air leak, seal it with caulk or the spray-in, expandable urethane foam sold in osthardware stores or home centers.

 

[pa-traveler]

heat exchanger? is that the radiator/condensor looking item? where would the air be coming from that i would need to seal it, from outside correct.

thanks again!

 

[Karl]

Right. The a/c has two radiator-looking items; one on the roof (the condenser) and the one inside the coach (the evaporator). Gary wants you to remove the cover from the a/c on the roof of the coach, and feel around any area where the a/c unit meets the roof surface. This would include any copper (sometimes aluminum) piping. If it's not breezy, try using a piece of toilet tissue or othere light paper, and see if it starts to lift or flutter as you move it around. I believe most manufacturers tell you not to use caulk, but if you remove the cover inside the coach, there should be mounting screws that you can tighten up a bit to compress the gasket. If that doesn't help, a gasket replacement is needed.