Recently, I have noticed water condensing on the supply ducts around the blower. I never had this problem with a CAC before. I am concerned bcs we just bought this place and I dont want water inside my walls how do I stop it. It has been rainy here and quite humid (Im in DC 'burbs). I was considering a dehumidifier but id rather solve the problem (if any). Alos please see my other post, related?
Several things. You could insulate the ducts and keep the humidity away from them. Add a supply and registers to the basement to improve airflow. But unless the AC is running a great deal you may need a dehumidifier to keep up. It sounds more like a moisture problem in the basement rather than a CAC problem. A dehumidifer running is cheaper than turning your CAC lower to remove moisture. Your CAC system may even be missized to handle this problem.
I have seen this problem before and your last reply is right. Due to the hi relative humidity, the basement is unusually humid and the cooler duct will cause condensation on your ducts. Do not worry about the interior walls. Dehumidifier in the basement is the only solution. Once the RH% comes down in the basement you can try leaving the Dehumidifier off.