Duct Work Sweating-Clifton, VA

Wednesday, March 22nd, 2017 by Justin Dobson

Challenge

This Clifton, VA homeowner was having issues with high humidity in the basement of their home. Plus, the HVAC duct work would sweat in the summer. When duct work sweats while inside the building envelope, the cause is hot/humid air entering and hitting these ducts. The air hits dew point and condensates.

Solution

Comfenergy performed a blower door test during an in home evaluation to find out where the hot/humid air was entiering the home. The basement rim joists were allowing the hot/humid air to enter the basement and then touch the ducts and walls to then hit dew point. Comfenergy insulated and sealed the rim joists with closed cell spray foam. The walls were air sealed and insulated using Thermax foam boards.

Project Summary

Evaluator: Carl Depner

This Clifton, VA home had high humidity in the basement and the HVAC ducts would sweat in the summer.

The rim joists were found to be allowing hot/humid air to enter the home. They were sealed and insulated using closed cell spray foam.

The cutting of Thermax foam boards in a tight area with many sensitive things to work around.

Notice how good this Thermax looks on the walls. Not only functional, but looks good too.

Another shot of the finished products. Closed cell spray foam in the rim joists, and Thermax foam boards on the walls. Thermax is used because it has a fire rated thermal barrier in the product to meet fire codes.

Back to Previous Page Back to Case Studies

Duct Work Sweating-Clifton, VA

Challenge

Solution

Project Summary

our service area

We serve the following areas