Quote Originally Posted by Abby Normal View Post
well meausiring at the diffusers then at the coil will tell you if you have duct losses for one.

measuring at the coil trells you what the unit is actually doing, measuring at the grilles tells you what the room is receiving.

When there is a big descrepancy (especially if ducts run in unconditioned space) there is room for big improvements to stop wasting energy


you move more air through a clean filter than a loaded one

I think you will be most accurate maesuring the air flow into the returns

Thank you guys.