Remember, these tips are not from TWB, they are from my facebook page, so take them for what they are. Happy gardening:
Nathan Sweet - Depending on the grow room and budget I would go with carbon filtration or a ozone generator.
Kehaulani Whaley - These wonderful drops from Japan. One Drop Deodorizer. Made by Kobayashi. In Hawaii we call them dodo drops. They really work! It's great for everything. Just add two drops in water or even the toilet and the smell is GONE!!!!!!! I never leave home without it.
Daryle McCoy - big fans ducted up and away---stuff the vent pipe with dryer sheets--sum1's doin laundry again??lol
Adam Scriven - I'd say carbon filter, that's always worked at the grows I've been involved with.
Harry Hydro - There is a deodorizer called ONA that is suppose to be effective used correctly...
Jeremy Archer - Ozone generator or deionizer
Mike Yazzie - Ionizer
Jim Freire - Constant air exchange with charcoal filtration is usually enough. but an ionizer in the exit stream will finish whatever the charcoal doesn't.