Number 302, Vent Block Cover. Air leaks can occur inside the house itself. You can pick up a pair of these magnetic energy conservation products at your local hardware or building supplies retailer.
Closing the vent in an unused room or in the basement will help reduce heated air from passing through the vent’s cover, but it will not stop it.
When you place a vent block cover on the vent, it will seal the vent cover so heated air only goes through the vents in the areas you are actually using in your home. We use one in a bathroom that gets too hot and several on the ceiling vents in the basement when no one is using that part of the house.
INSTALL COST – Cheap INSTALL COMPLEXITY – Simple
FREQUENCY – One Time FINANCIAL PAYBACK – Moderate