That's is a bi directional drier that came with the Acadia unit. Humidifier is not required. I'll see how it works without. I can't really figure out the benefit of one at this point.
I still don't get the gas line question when the gas has to do with the old unit. What am I missing here? I'm not even sure what before means in this case. If you look at the floor the drip leg looks to be before the gas shut off in the propane furnace.