Does it provide more efficiency to close all HVAC return vents except for 2? And to move them to the ceiling?

Question

My A/C guy told me it was, but I've always heard the more return vents the better. He also told me to move them to the ceiling instead of the floor.

Answer 1

ideal situation would be to have high and low supplys and returns- In winter open low supplys- hot air rises, in summer open high supplys- cool air falls . gives better air circulation and more even temp. return air vent square footage should at min. be equal to supply preferably larger.

Answer 2

you have a certain amt of cfms for your unit yes the more return the better don't close any off without replacing it and yes my opinion the ceiling is better