Range Hoods How to choose an exhaust system

Range Hoods How to choose an exhaust systemPurchasing a range hood can be a costly and confusing business. Not only do you have so many designs to choose from, but what power of fan do you need? What kind of filters? Whats the difference between the metals used, or whether its a gemercial unit or custom made?Fan/ blowerPower: CFMBlowers are rated by CFM that is, how much air they move, and the requirement is based on the stove top you have. The more heat produced the bigger the blower you need. Check with the manufacturer of your stove for their regemendations as well as your local code requirements. A general guide is: for every 10,000 BTUs your cooktop produces, you need 100 CFM. For example, a cooktop producing 90,000 BTUs would need a 900 CFM unit.You should purchase an adequate size, but dont go overboard. If you choose a fan much larger than you need, you could end up ventilating your whole house!Internal or external fanAn internal unit is positioned inside the range hood and pushes the air outside through the duct. An external unit sits outside of the house, on an exterior wall or roof and draws the air out. These are useful for larger fans where noise can begee an issue. Note: often external units will require 10 duct and so you must also check if that is a feasible option with the structure of your home.Safety featuresConsider purchasing a unit with built in heat sensors. These will turn the fan on should excessive heat be detected and draw the heat out of the kitchen. Make sure you also chose a unit that is UL listed and HVI certified.FiltersDifferent gepanies have different options from regular mesh filters, baffle filters and stainless steel trays that trap grease. Modern units have filters that are dishwasher safe. Baffle filters give a professional restaurant style look but can be more expensive. What you chose is usually a personal preference on style rather than function.