Air Conditioning - Condensation from ducts inside ceiling making ceiling wet

Newly installed A/C at same time as basement renovation. New unit went in almost same time as basement was finished. The new sheetrock (not painted yet) on ceiling is now very wet. It has been humid here in NY but not overly so and not even that hot. (Odd summer in NY when it only gets to 90 once and humidity is manageable). I hesitate to paint this basement until I get this solved. It can only get more hot & humid here and I'm worried about a big problem with the ceiling falling apart and mold, etc. Right now I have the 2 duct openings covered with cardboard with very little venting. I would damper off this duct except that it is the only air supply to my bedroom after passing through the basement. Should I take section of ceiling down to insulate duct and how and what type? If so, can this sheetrock be reused? Any help appreciated.

Lost here Did you shut off the registers down in the basement there???? They where there to help get the humidity out of the home so the duct dont sweat. Open them up and let it all dry out. Have to hold off and see what the drywall will do after its dry.

ED :eek:

gonna have to open it up to see what is going on. possibly the drywall dust is restricting airflow, causing the suction line to freeze up or sweat on your sheetrock

this is why i do not recommend sheetrock cielings in basements

Well, I hired some "excellent" contractors. Friends & friends of friends, you know what I mean? Anyway, there still are no registers in the ceiling. There are the cutouts in the ducts where the registers will go and they are currently covered with cardboard. My contractor has abandoned the job and i am stuck to fend for myself. When it was very humid a couple of days ago the duct openings were sweating terribly and the ceiling was seemigly drenched (where the duct ran above it). Ceiling is now dry with no apparent damage but as stated previously I am worried about mold and long term damage to the sheetrock. I want to solve this before I have some tapers come in to finish the rest of the room. I'd like them to be able to redo the ceiling, if necessary, at the same time. Should the portion of ceiling be removed and insulated? Thx.

Im with Mike all basements should have drop down ceiling in them . Now the duct sweats down there cause you dont let some air out there to get the humidity out of there. When you start to tape it has to run most of the time to help dry it out there. Like said is the filter , A coil and the blower clean so air can get through.

ED ;)

Thanks for replies. Unfortunately it's too late for a drop ceiling. One other thing may or may not matter. I see no return ducts anywhere down there. I believe there used to be one right before the air handler but the A/C contractor got rid of it when the new unit went in. Do I need one there and would it contribute to my problem? Also, Ed. I didn't understand much of what you said in your last reply. Thanks

Yes you have to have a return down there. You have to let the AC air out down there to dry things up. If you dont the ducts will sweat.

Ed ;)

Can i just crack the registers open a little bit? I don't want to give too much flow to the basement since it is already cool and I want to have good flow to my bedroom. Also, can I install a return vent right on the main return duct, right near the machine? In other words, will that satisfy the return requirement down there since the unit is in the basement?

It's best to put basement returns as far away from the furnace as you can so you don't rob combustion air or pull flue gasses from it. It's best to run them to a side wall and down to the floor.

How can I keep maximum flow to my bedroom if I am opening the registers in the basement? Again, the duct runs through the basement, has two openings for registers, then continues and ends at my bedroom.

Just open them a little is all for now. Have to dry out the basement also with the AC.

ED