I've got a bit of a situation with my AC ducts that I hope someone can shed some light on. I live in Northern Virginia, where winters are cold and summers are really humid. My older townhome has the AC unit on the roof, and this winter, water started pooling and dripping from my upstairs bedroom vent. I figured the exposed duct was getting cold and causing the warm air in my home to condense. After halftime of the season, I had my HVAC guy come out, and we replaced the old, crummy ducts with insulated ones, and I even replaced the roof at the same time. Things looked good until summer rolled around. Now, with the AC running, the ducts became cold again, but instead of dripping inside, I see condensation forming outside due to the warm air outside hitting the cold metal duct. I had insulation wrapped around and foam sprayed, but I'm still noticing some condensation, which concerns me about possible mold if it's on the inside. I get that moving the AC unit might be the ultimate fix, but that's just not in the cards right now. Am I destined to always have some moisture issues, or is there something more I should be doing? Any advice would be great!
3 Answers
It sounds like the main issue could be improper sealing and insulation. Condensation happens when there's an air leak allowing warm, moist air to contact cold surfaces like your ducts. Try to find any gaps or unsealed joints where air might be getting in and seal them. Ductwork is often an afterthought in homes, which means it rarely gets the insulation or sealing it really needs to perform well. Getting those seals just right should reduce condensation substantially.
Also, keeping ducts in unconditioned spaces can really mess with you. A little more insulation can go a long way!
Have you cleared the condensation line on your HVAC? Sometimes, if that line is blocked, it can cause water to back up and leak down onto your ducts. It’s worth a look, especially if the duct runs a bit away from the unit itself.
That's a good point! It might be far but worth checking just in case. A backed-up line can definitely mess things up.
Right? Could save you a headache down the line if it’s an easy fix!
If the ducts are in a humid area, you might need to consider using a dehumidifier. That's how we keep our basement dry during summer. If there's no moisture in the air, there won't be condensation forming on your ducts at all, even if they're a bit exposed.
That’s a solid idea, but it sounds tricky with your crawlspace setup. Still, if you can find a way to manage humidity, it'll help a lot.
Definitely check options for dehumidifiers! Even if it seems complex, it can be worth looking into.
Totally agree! It’s surprising how many ducts are just left exposed without proper care. If sealing the joints doesn’t help, consider checking the overall air quality and humidity in that space.