Who Makes a Closeable Outside Air Supply?

Looks like we will be installing a zero clearance, wood burning, high efficiency fireplace in our new home. All of the units under consideration require outside combustion air intakes, but none of them come with CLOSEABLE intakes. I would like to be able to close my air intakes when the fireplace is not being used, but I cannot find any closeable air supplies. I have read that there are closeable intakes which are cable operated and some that are electrically operated, but hours of searching has yielded no sellers or manufacturers of these items. Does anyone know where to find a closeable outside air supply for a wood burning appliance? Thanks in advance....

Call a Kozy Heat Dealer. part #940

Hey, that's great! Thanks a lot, friend!