Comments about Thermastor Santa Fe - 8" Supply Collar (4020623):
We assembled a standby 25 ft long 10 inch flex duct
The assembly required an 8 inch splice joint (crimped both ends) and 8 to 10 inch expander in addition to the optional collar.
We keep the flex duct assembly "at the ready" to dry out far corners of basement (only when needed)
We use a second 8 inch splice to help direct the blower exhaust away from the unit in normal operation
To change operating modes, we remove the stand alone 8 inch splice and insert the crimped end of the second 8 inch splice (integrated with the 10 inch flex duct assembly) and point the duct exhaust toward a corner that needs any extra attention