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Water coming down from vents in winter.

I have this problem every year. On my a/c system two of the room vents that are furthest away from the air handle have water dripping down in the winter. They are the plastic type that close with a screw drive in the middle. I know there isn't a complete seal on it. Once I tried to tape plastic over them but the same thing happened. The run of flex pipe is sort of straight with hardly any play to it. As of now I just go up in the attic and disconnect the flex every fall and go back in the spring and put it back together again. I have asked a few a/c techs about this but no one has the answer.
Any ideas? Thanks


  • JohnWayne
    JohnWayne Member Posts: 31
    edited September 2014
    Is your system a heat pump system? Try sealing the duct to the vent and insulating it somehow. It sounds like condensation is building there and dripping down.
  • Tony Massi
    Tony Massi Member Posts: 86
    No its just used for air conditioning. I know when warm air hits a cold surface it loses its moisture. The flex pipe is insulated I would think it would be enough. I wonder if they make flex pipe that's super insulated.
  • don_9
    don_9 Member Posts: 395
    Does your window sweat as well? Try blocking off the return instead n see if that helps.just thinking convection may need to bring in some cold fresh dry air in to the home to reduce that latent load.
  • Tony Massi
    Tony Massi Member Posts: 86
    There isn't much insulation around the ceiling boxes.
  • Tony Massi
    Tony Massi Member Posts: 86
    Don, The windows are Andersons and don't have any sweat on them. I always block off the return for the winter. One time I found water up in the return duct so I blocked it off. The problem was so bad that years ago I removed the supply to the bathrooms. Its really a puzzling situation.