Range hoods should be ducted to the outside of the home. While non-ducted filters trap some of the grease and odors from normal cooking, the humidity, smoke and heat will all be re-circulated back into the home. If the non-ducted filters are not regularly replaced, eventually the grease and odor catching effect will no longer protect your home from impurities.
High BTU gas cooking equipment should always be ducted to the outside of the home. If this is impossible, high performance convertible hoods and filters are available in some models. Contact the Technical Support Group.
Range hoods must be vented using metal duct. Given a choice between flexible metal duct and smooth metal duct, go with the smooth. The ridges found in flexible metal duct create turbulence and will diminish airflow.
CFM stands for Cubic Feet per Minute of exhausting air flow. The higher the number, the greater the amount of air that is exhausted using the Range Hood.
A Sone is an internationally recognized unit of loudness. Sones are a linear measure like inches. Doubling the Sone value is equivalent to doubling the loudness. To get a sense of what one Sone represents, one Sone is equivalent to the sound of a quiet refrigerator in a quiet kitchen. Typically, the Sone level is measured at maximum CFM (speed), however, some newer products are also being tested at normal CFM (speed) settings to provide consumers with typical sound level information
The term convertible refers to a hood that can be installed in different ducting modes. Typically a convertible hood can accommodate: 7" round ducted, 3 ¼" X 10" vertical or horizontal ducted and non-ducted applications available at installation.
A convertible hood has both ducted and non-duct features built-in or the appropriate parts are provided in the box at the time of purchase. Therefore you have the option to install it without the additional purchase of special parts or kits. However, the charcoal filters needed for a non-duct hood may need to be purchased separately.
A range hood that is designed to be ducted and can also be installed as non-duct with the purchase of a parts kit and charcoal filters is non-duct capable. When a hood is installed as non-duct it re-circulates the air in through the filters and out through vents near the front or top of the hood in a continuous circulating fashion.