I have an early 1990's furnace. It takes its combustion air for the burners from the basement. I'd rather feed it some outside air using a duct that opens when it runs and closes when its off. However, I've been told not to feed cold air to the furnace burners or I'll get corrosion from the moisture. Thing is, there is less moisture in the outside air when its 15F outside than the 65F air in my basement, so how can that be? What is wrong with feeding cold outside air to the burners, as long as it stops when the furnace is off?
thx Dan G.
By the way, codecheck.com is still off line.