I'm finishing up my basement bar that includes a range with a grill.
These beasts tend to generate some smoke, so a vented exhaust is a
must. I've got a nice, beefy blower, but I'm concerned that the 20'
duct that will be installed above the suspended ceiling will leak
smoke and/or grease, particularly since the blower will be installed
at the hood, meaning that there will be positive pressure along the
entire length of the duct. How can I minimize this? 4" PVC would be
nice, but I suspect that it wouldn't be well suited to this
application (and probably not code). What are my options?