“Smooth” flex duct
I understand that flex duct is bad in most situations–it decreases blower efficiency and just generally impedes air flow. That said, for a longish (25ft) run of 6″ duct, I wonder if it wouldn’t be okay to use one of the ‘smooth wall’ plastic ducts on the market (see http://www.flexaust.com/product/grass-collection-vacuum-hose/) for a good example of what I’m looking at. This would be in a relatively low-pressure type of situation (Minotair hybrid HVAC system installation). The ‘problem’ with using rigid metal in this situation is that the TJI floor joists are spaced at 16″ o.c., so it’d involve a lot of mastic and short sections of rigid pipe to get this done. My thought is that if using this kind of pipe saves me X hrs of labor, that covers the add’l cost quite quickly…
Any experience/thoughts out there?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part