Gas and Oil Home Heating Furnaces - Condensation around ceiling vents

I live in north central Texas. My AC runs May thru Sept. This last year I noticed condensation around the vents in my Living Ceiling causing water spots in the ceiling. What is causing the condensation? How can I stop it?

What is probably happening is the register box in your ceiling isn't insulated, or isn't insulated well enough. We put vinyl faced insulation around the entire register box and strap it with duct tape. Then we put the house insulation back around it as toght as possible.

The reason for the condensation is the hot humid air in the attic is contacting the metal register box and being cooled below the dewpoint. The moisture forms on the box and runs down into the ceiling.

Hopefully you can gain access to the area and insulate around the boxes.

Thanks. We have been in the house for 4 yrs. This is the first yr I've noticed this. I will have to check the register boxes.