Kat, Thanks for the dance. It must have worked. It's been raining off and on since midnight. We still can't see very far but it's hard to tell if it's smoke, mist, or both that's blocking the view.

My furnace does suck the air in from outside. There is a 6 inch diameter pipe that runs from the furnace plenum along the unfinished ceiling and exits above my laundry window. I had a good look last night. I can see no means inside the house, or on the furnace, to block it.

I don't think that the filter on the furnace would keep out the smoke. Many years ago, when my dear father would visit in winter, he'd go to the basement to smoke his cigarettes as we were non-smokers. Dad thought he was being considerate by not smoking in the living area, but he'd pace near the air intake on the side of the furnace and the smoke would be distributed throughout the house.

So far I've been able to keep the furnace from coming on. I'm hoping that the fires will soon be under control and this will become a non-issue.   

rags