A Condo, here on Long Island where the climate is all over the place, has 2 floors. Each year around June a leak develops in basement from duct work. I can see the seam. My questions is has the humidity rises in attic is this what causes leak? If so is there a dehumidifier for attics? Or should I just seal seam and wait see what happens?
Thank you for your time
Replies
It's really hard to say what causes it. Most likely it's outside air coming in contact with a cold cooling duct, but that could happen in a number of places. Is there cooling ductwork in the attic? If so, is it well-insulated (with the seams in the insulation tightly taped)?
Somewhere hot, moist outside air and cold AC air are coming together. (Assuming that the problem isn't simply a clogged AC drain.)
Not directly relevant to your question, but a week ago we suddenly had a problem with the overhead fluorescents in our kitchen not starting. There are 3 2-tube units, and only one of them would even flicker. Had not had trouble with them since the last time I replaced the tubes probably 5 years ago. (It may be nearing time to replace them, but they never all go at once.)
Checked the voltage at the switch and it was OK (and no reason to suspect the wiring anyway). But then, while I was futzing, one of the units started.
Then (cough) a light bulb went on! The fluorecents are in a coffered area with tightly-fitting translucent panels below. Above is the attic, ventillated to the outside where dewpoints were up into the upper 70s (rare, even for here), below is the air-conditioned kitchen, where the temperature was in the lower 70s. The translucent panels are a darn good vapor barrier but a lousy insulator. (And the drywall ceiling above lacks any sort of vapor barrier.) Condensation was no doubt forming on the tubes, and condensation will prevent them from "igniting".
Opened up one of the panels a crack (until the dewpoints went down) and had no more problems.
(Another possible point of condensation is an uninsulated refrigerant line.)
Condensation, de humidifiers.
Most condensation is caused by people, cooking, washing, drying things, breathing.sweating.
The water vapor we create in our homes heads straight for the nearest cold surface to appear as condensation, or if its wood or paper the condensation forms inside the wood or paper.
A de humidifier provides a very cold surface for all the water vapor in your home (and outside) to condense on.
There is no point in running a de humidifier, if there are holes in the walls, ceilings or floors. If there are holes, then the water vapor in the outside air rushes indoors, heading for your de humidifier. You end up spending a lot of money trying to dry out all the air in your country.
The air outside is usually colder and dryer than the air indoors, that's why we open windows. But in your area it does get both hot and sticky outside, and you must seal up your home, make it water vapor proof to stop the water vapor coming in.
Then you can run a de humidifier and get. the benefit.
You don't seem to be answering his question about summertime condensation, when the air outside is warmer and moister than the air inside.