DIYbanter - View Single Post - Cold air return near the ground or ceiling?

wrote:
So it sounds like I can keep the basement air return and do some
blocking between seasons to see how this affects temperature among the
3 levels.

One last question. What is this backdraft danger for some instnaces
where air returns in teh basement can cause? Still can't wrap my head
around this yet. Any help would be greatly appreciated!

i would not block any air return. unless you enlarge another return in
some other location. you have to do calculations on returns so you don't
put strain on the blower.