I live in northern Minnesota and have a microwave/hood vent over our kitchen range. It is vented directly outside through the 6 inch wall. Unfortunately in the winter the NW winds blow directly at the outside vent and overpower the spring loaded flapper. The microwave is colder than our refridgerator and moisture freezes and then melts and leaks down the wall from behind the microwave/hood. Is there any product that would make the venting system tighter and more energy efficient?? Or is there a way to make it more energy efficent considering the fact that there is only 6 inches of ducting and that is through the wall. Also would like it to be somewhat unobtrusive since it ducts into an outside area that is part of our deck.