Air conditioner drafts in winter

[daveola]

I'm starting to make my bus a little more insulated/sealed (it's getting chilly!) and I noticed that there seems to be a draft at my two rooftop A/C units.

I see that covers are available at Camping World et. al, but they seem to be more for cosmetic protection and are only usable while parked.

Is there some better insulation method for A/Cs?  I'm thinking of making some sort of insulation cover for the inside part of the unit and just taping it up for now.

[cody]

Some people make insulated covers for them that attach with velcro, seems to keep down the drafts somewhat lol.

[PCC]

One way I have found works to stop drafts from roof top vented A/C - heat systems, is to install a metal piece around the vent openings in the ceiling and use a magnetic sheet to cover the opening on the inside.

That does not release from the responsibility of making sure that moisture does not get into the coach to that point, or it will ruin the ceiling, but the magnetic sheet certainly stops drafts, or any air loss through the vents.