Furnace Ideas / Help

Del is full of good ideas. Put your light bulb heater on a thermostat, you'd have to find an industrial one that goes down to about 35*F. If the botton of the furnace is the return, and there's enough room, the heat should rise enough to keep and condensate from freezing. The traps hold the majority of the condensate, no need to worry about the exchanger. And the relative humidity is typically lower in freezing weather anyway, so a light bulb is likely adequate. It works for chickens in the mid-Atlantic.