How to hook up a ducting to the ceiling?

Use drywall anchors for the flange if ceiling is drywall of course and dont foget backdraft damper

Sent from my SGH-M919 using Rollitup mobile app

U need 1 flange no need to run ducting in attic unless u dont have gable vents which most attics do. U drywall anchor flange to ceiling cut hole, install backdraft damper and then duct as for the fan try to hang it close to hood flange

Sent from my SGH-M919 using Rollitup mobile app

Having a construction background............priceless!!!!