Since our attic was so hot and humid, our HVAC technician recommended installing a standalone dehumidifier in our attic; he also encouraged us to check our air filters more regularly, since dirty air filters put more pressure on the cooling system, which also contributes to condensation
A few months ago, while hanging streamers for a party, I noticed a slightly dark spot in my ceiling. It was bizarre, and I had never noticed it before; the spot was like a grease stain, or a slightly dark spot of water. I assumed that my roof was leaking, but after calling out my roofing contractor, they determined that it had nothing to do with the roof. My wife suggested that it might be duct condensation, and she turned out to be correct! An HVAC technician came out, and confirmed her suspicions. It was a very hot summer, and our air conditioning system was working overtime to cool our home. The cooling system expert told us that ducts are like a glass of water: when it’s cold inside the ducts, and hot outside the ducts, condensation forms. We live in an older home, and the insulation in the attic isn’t exactly tip-top. The temperature of the air outside is essentially the same temperature as the air in the attic, so the blazing summer heat really does a number on our ducts. Since our attic was so hot and humid, our HVAC technician recommended installing a standalone dehumidifier in our attic; he also encouraged us to check our air filters more regularly, since dirty air filters put more pressure on the cooling system, which also contributes to condensation. While the technician was up in our attic exploring our ductwork, he discovered some leaky ducts; the more air that escapes, the more likely it is that condensation will form, so his visit alone was a huge first step in solving our problem! We were very lucky to have the advice of a trained HVAC professional to solve our duct condensation issue.