Any ideas from forum members? Got a convection microhood over a range. cold air pours in through both air doors,one at the back of the range hood and the other on the exterior of the wall. Both doors have springs that hold them closed when not in use but a lot of cold air gets by anyway. (poor design)So much so that the air condenses water drops on the back wall of the microwave interior. In the morning theres a puddle of water in the microwave. Possibly why the magnetron and capacitor had to be replaced after only 6 months. As the house is a 2 story air likes to chimney here that is come in on the first floor where ever and Warm air exit on the 2 nd floor from where ever. After several years of this i am considering closing up the whole thing and using the indoor vent feature.