Water coming down from vents in winter.

Tony Massi

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

MichaelK

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

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.

MichaelK

I would check and see if the inside of the flex gets wet and the water travels along the inside. You may need to check the seal that the main trunk and where it connects to your diffuser or vent in the room where you have the leak. Make sure the seal is as air tight as possible so the cold attic air isn't getting in. Also try turning on just the fan and let that run while you check along that flex line for any tears or breaks where air is blowing out. If air gets out in the summer, cold air may be getting in during the winter. Also make sure around the vents in the attic there is insulation where they are pressed through the ceiling. Even plastic vents will sweat, not as badly as metal vents, but it still happens. Hope some of that helps.....

Techman

They do make flex w/ thicker insulation. The existing flex might be bad. Is there lots of insulation around the "ceiling boxes" up in the attic as John Wayne said.

don_9

Does your window sweat as well? Try blocking off the return instead n see if that helps.just thinking convection currents.you may need to bring in some cold fresh dry air in to the home to reduce that latent load.

Tony Massi

There isn't much insulation around the ceiling boxes.

Tony Massi

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.