Slightly OT, but in the last years I've built both a dust collection system for the polishing wheels in my shop, and an exhaust hood for my kitchen. Unhappy with the prices and designs of existing products, I set out do kludge something together myself. I ended up getting the hose from an Ebay shop specializing in a certain type of indoor agriculture, where the crop gives off a pungent odor which must be filtered. The hose was of decent quality, and much cheaper than what the industrial suppliers were asking. Don't know if this helps, but it's amazing what alternatives can be out there if you look hard enough.