This tidbit in the manual was also interesting:
Use of 2? ducts does not count toward achieving minimum discharge
requirements. Ducting in dead air space with no return air, such as
holding tank areas, does not count toward achieving minimum discharge
requirements.
I am almost certain my ductwork in the floor is 2". In that case, I'm still not meeting the minimum requirements.
Another tidbit is this:
DO NOT install floor registers within 2 feet of return air openings
In my case, I have no floor registers anywhere near the furnace, and I cannot find anywhere else in the manual where it says not to supply hot air near the cold air return (Except when using in-floor hard ducting).
My personal opinion on the matter is that because the amount of air flowing out of a register is not very forceful, the furnace can pull that heated air directly back in to the furnace. In the case of my installation, the air coming out of the duct above the cold air return moves up and away at a rate faster than the furnace draws fresh air in.
Either way, it may be a good idea to rebuild my access panel as I mentioned above, with the cold air return vertically on the left and the supply over on the right to at least satisfy the 2' "in floor ducting" rule.
Other than ducting into the bunkhouse, which I've already stated is not an idea I'm willing to explore, where *else* would you suggest I add supply?
