Air ducts?

[BonesD]

The central heat/ac on my boat is mounted in the engine room.
The duct work which is a flexible 8” or 10” corrugated hose I believe is permeated with engine room smell/diesel. This hose runs to a register in the Pilot house and another down below in the cabin. When ever I run the heater it fills the cabin with stink even though the engine room now is pretty clean. The intake for the system is in the cabin so it is not the source.

Is there a replacement hose anyone can recommend that is less permeable to odors? Maybe it’s just time to change the hose in a forty year old boat?
Thanks

[tkeithlu]

Corrugated hose in those diameters is cheap, so one answer is "Go for it." However, it is possible that the problem is engine room air leaking into the hose on the suction side of the blower. I'd check carefully before concluding that permeated hose is the source of the problem. I suggest that you look for cracks and hose clamps that don't really seal, plus cracks in the blower housing as well.