It won't be long until I'm ready to have my self-contained AC condenser unit installed. I will install the return air grill in the floor and the damper underneath the main trunk.

1. The manual says to install the damper forward of center of the home.
2. I will minimize the supply and return duct lines as much as possible.
3. I will keep the damper at least 3 feet from a floor register.
4. I'll not install the return air grill in a high-traffic area.

My question is this:
How far from/close to should the damper be installed from the return air grill that will be located in the floor?