Hot take: Overdimensioning ductwork is actually better than following the manual

Last week I retrofitted a small office space in Austin and ignored the standard friction loss charts, bumped the main trunk up by 2 inches. Everyone says stick to the numbers, but I've had zero noise complaints compared to the old system that was 'perfectly spec'd'. Anyone else find manual specs don't account for actual install conditions?

2 comments

2 Comments

tessa39417d ago

Hmm, bumping the trunk by 2 inches is a pretty big jump - that's a lot more volume than you might think. In my experience, oversizing by just an inch or so can sometimes make the airflow feel uneven in the farthest rooms, especially if the branch runs are still tight. The noise complaints going away is nice, but maybe the old system had dampers that were fighting too hard against undersized runs. It's worth checking the static pressure at the farthest register - if it's real low, you might have actually made it harder for the system to push air to those corners.

wren82617d ago

More trunk volume without matching branch runs just moves the problem downstream.