This document looks helpful:
http://www.sdcounty.ca.gov/deh/food/pdf/publications_ventilationguideline.pdfIf I'm reading this right, it's recommending the following for stovetop, non-grease application:
Hood should be no more than 4 ft above the cooking surface
Hood should overhang cooking surface by 12-18 inches on all sides. To me this implies a hood that's roughly 4 ft by 4 ft.
Minimum flow should therefore be 75 ft/min x 4 ft x 4 ft = 1200 cu ft/min
Duct diameter should be at least 11 inches to maintain a duct velocity of 2000 ft/min.
1200 ft/min of tempered makeup air must be provided.
This is my guess based on a smidgeon of knowledge and about 10 minutes reviewing the guidelines.
I've been curious about this since I've been wondering about brewing in my basement. It looks like quite a bit of mechanical work if you want to comply with the codes and be safe.