Fixed my whole house air balance with a $20 damper and a thermometer

I was at a hardware store in Nashville last spring, complaining to a guy in the ductwork aisle about how my upstairs bedrooms were always 10 degrees hotter than the living room. He just looked at me and said 'you ever check your branch dampers?' I told him I didn't even know those existed on a residential system. He walked me over to the manual damper section and showed me how to cut one into a run. I spent that Saturday crawling through my attic, found the flex duct for the upstairs zone, cut it and installed that $20 damper. Then I used a simple meat thermometer stuck in a vent to dial it back until the airflow matched the downstairs. Total cost was less than a service call and my bedroom temps dropped from 78 to 72 on hot afternoons. Has anyone else actually messed with adjusting dampers or do most people just call a tech for that?

2 comments

2 Comments

owens.nancy10d ago

Grab a laser thermometer next time, it's way easier than crawling around with a meat probe. I found a cold spot in my ductwork that was basically a free AC leak, patched it with some foil tape and it made a bigger difference than the damper adjustment.

dianagreen10d ago

Never thought about using a laser thermometer there @owens.nancy, but you've changed my mind completely.