Range Hood Duct Size

Here is a breakdown of the duct size you need based on your range hood s cfm.

Range hood duct size. What is the minimum duct size for a range hood. A 0 to 400 cfm fan requires a 4 inch minimum duct size but a 6 inch duct is recommended. The size shape length turns and cap on the range hood ductwork adds resistance which reduces the amount of air the vent fan can move requiring additional cfm for the fan. The smaller the duct size the less cfm you need and the larger the duct size the more cfm you need.

The 10 size will accommodate every speed. When using smooth round 8 diameter metal pipe add one cfm per foot of pipe plus 25 cfm for each elbow and 40 cfm for a roof cap. If you have a range hood with a cfm of 0 400 you will need a minimum duct size of 4. The more cfm your range hood has and the longer you need to run it the larger duct size it requires to vent the unwanted air out of your kitchen.

If your hood is between 601 and 900 cfm you need a minimum duct size of 7. If your hood is between 401 and 600 cfm you need a minimum duct size of 6. Take note of the size and position of your kitchen range hood. The minimum recommended duct size is 6 for 0 400 cfm range hoods.

Kitchen hood exhaust duct size. The ductwork should be 12 in diameter if it extends more than 100 including the 10 reduction for each elbow. For more information on duct size click here.