wrote in message
ups.com...
What you will likely have is some pretty extreme stratification, where
the elevated returns are, besides reduced heating efficiency.

At least if he put the discharges near the ceiling with the returns
below, you'd have a manageable loop, just be overheating air at
ceiling.

What I've found to work very well, for heating and cooling is plastic
flow-diverters that magnetically attach to registers.

If the duct is extended, you have two outlets. Open one, close the other,
depending on season. I've seen that done with good success.