LEED (Leadership in Energy and Environmental Design) is a voluntary, consensus-based, market-driven program that provides third-party verification of green buildings.
Among the requirements is the need for positive closure of openings between the home’s rooms and the attic.
There are several ways to accomplish this.
Airscape does it with motorized doors in some of their systems.
Invisco offers the option to use motorized doors with all of their systems. Invisco also offers optional R60 insulation for all systems.
QuietCool does not offer any positive closures in their ceiling fittings, but since they use standard duct sizes their systems could be retrofitted with the Invisco motorized doors and/or R60 insulated systems.
Tamarack offers excellent motorized doors available in both R38 and R50 rating.