If you are going to install a new cooker hood or replace an old one, venting outside is the best option. The most common types of venting systems are ducted and non-ducted. Ducted systems use a metal or plastic pipe to carry air from the hood to the outside of the house. Non-ducted systems use a charcoal filter to trap pollutants and recirculate air back into the kitchen.

Non-ducted systems are easier to install because they do not require a vent to the outside, but they are less effective at removing pollutants from the home. They work by trapping pollutants in a charcoal filter, which should be replaced regularly. Non-ducted systems are best used in homes with relatively clean air and low levels of pollution.

There are some situations where it may not be possible or practical to vent a cooker hood outside. For example, in apartment buildings or homes with shared walls, installing a ducted system may not be allowed due to building code restrictions or neighborhood covenants. In these cases, a non-ducted system may be the only option.

Non-ducted systems are easier to install but may not be as effective at removing pollutants. Regardless of which option is best for you, make sure to check your local building codes and follow the manufacturer's instructions for the proper installation and maintenance of your cooker hood.