Ducted range hoods draw exhausted air into its ventilation system. The air is then filtered and released outside of your home. These units are premium because they are capable of keeping the air in your home clean even while you are using high-powered gas ranges and cooktops.
Non-Ducted range hoods are designed to pull the polluted air into its ventilation system where it is filtered and recirculated back into your kitchen. These units purify the air allowing for a clean and efficient recirculation of the air.