It has been quite hot and humid lately and we’ve run the A/C a bit. Yesterday, I discovered wet walls and dripping condensation in the little closet where the blower unit is. Never had this before. The condenser is actually on the roof of the building. The walls are now already spotted with mold and they’re still damp even though the A/C is off and temps have cooled down and the humidity is down. Is there something I can spray/paint on the stack or the walls that will absorb or eliminate the condensation? Or am I looking at the wrong spot for a solution?
First make sure that it is condensation forming in that closet and not leaking in from somewhere else. It could be condensation forming in the ducts and dripping back in there. You can make the walls more waterproof but that’s not going to eliminate the condensation and you probably don’t want those walls absorbing moisture. Also check for a drain hose in that blower unit that may be clogged.
First of all, you said your condenser is on the roof. The condenser doesn’t cause the surrounding air to condensate. The evaporator does. That’s the part that’s typically integrated with your furnace (and uses the furnace blower). I’m assuming the evaporator is in the closet. In either case, it shouldn’t be making the walls wet. Typically, if it makes anything wet, it’s the floor because a drain line is clogged and it’s overflowing and making a mess.
Check to make sure there isn’t any cold air escaping around the duct work in the closet. Something like that could do it. If you blow cold air into a hot humid closet, I could see that causing problems.
You could also try leaving the door open for a few days and if it has anything to do with the AC, that should dry it out since the cold air (and condensing humidity) should just get blown out of the closet.
If, even with the door open, the walls continue to get wet, I’m going to say it’s coming from elsewhere. Check for leaks above or next to the room. Including making sure duct work running above the room isn’t condensating and dripping.
Mine is in my basement and the drain that the AC routes to is higher than the evaporator so there is a pump with a small tank that pumps the water up to the drain. If the pump gets clogged or stops working you may need a new one.
I agree with those who have said to check the drainage from the indoor portion. We’ve had issues with that - most recently, when the floor drain somehow got clogged (had to have a plumber out to snake it out); it was soaking all the carpet just outside that room. Before that, at our previous house, the neighbor’s drain pipe had become dislodged and was letting the condensed water trickle along the floor to the dividing wall between our townhouses (nearly ruined the sale of the house for us).
Do you have an upstairs neighbor whose closet might be just above yours? That’d be the most likely culprit, if your drainage is working OK.
Try running the A/C for a bit and make sure there is condensate coming out somewhere, and that the “somewhere” is the right place (i.e. into some sort of floor drain). That’ll rule out it being your unit that is misbehaving.
[quote=“Mama_Zappa, post:5, topic:919313”]
Do you have an upstairs neighbor whose closet might be just above yours? That’d be the most likely culprit
[/quote] Nailed it. Their drain pipe got clogged and for several days it just dripped onto their floor and then into our A/C closet. Our system is fine. But now we have to have our walls replaced. Oh, well, it’s always something.
Aha - THEIR insurance should actually cover the repairs to your place since they are at fault.
“Should” being the operative term. Given the scope of the work to be done, I anticipate their insurance company hiring the Grace L. Ferguson Airline and Interior Repair Company to slap together a cheap, half-assed job. But that’s a different thread.