Mike, Often times in my area as well as yours I'm sure , The 70's style "shoebox" ranch only has two gable vents. Not the best design as it only works when the wind is blowing the right direction. and as Murphy prevails it's usually not that often. As it is not always cost effective to install soffit vents or pay your local roof monkey "no offense intended, I personally am a ladder monkey myself..." to cut a bunch of holes in the rood for roof vents, it would seem that the logical and more cost effective solution would be to install a vent fan with a humidistat or thermostat. Charlie, If I'm understanding your statement correctly, by media you mean the stuff that triggers the switch like mercury in old therms? than I have no idea. what is it?