I have a new 1850 sf two story home. My cold air returns are are in the living room and directly abpve in the bedroom. They are so noisy when the a/c or furnace kicks on that you can't hear anything else. The noise is a wind noise, like a blowing sound that is so loud I'm ready to sell the house if I can't find a solution. Any suggestions?

Do you know what size unit you have and what size your returns are? Usually a noise like that is do to the return air grilles or duct work, being to small. Have you looked to see if there are air filters inside your return air grilles? Some returns have filters in them and if it's real dirty you'll hear the air trying to suck through it.

Also try, if possible to adjust the fins on the return air grilles, just take a pair of needle nose pliers and slightly bend each open a little more a small amount. Make sure you get each one even, this may help... if it doesn't I would agree w/ jackt in saying it may need a little more return on the system