Flex Duct Cfm Calculator

Cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12.

Flex duct cfm calculator.

Calculations are for 60 f dry air at sea level from 5 to 3000 cfm approximately standard air which is 0 075lb da ft. Read duct diameter inches and duct velocity fpm. Duct cross sectional area air flow rate and air speed are used in calculating the duct size. Sheet metal duct friction loss calculator.

Include fittings in the duct tel enter either. Equivalent diameter is the diameter of a circular duct with similar pressure loss as an equivalent rectangular duct. If ashrae 2013 is selected flexible roughness is 0 003 ft when straight and fully stretched tight at 0 compression adjusted at other compressions otherwise the. Select the duct type on the pull down menu.

Fpm is velocity in flex duct feet per minute. Click calculate and you will see the size of flex duct you need for that room. Based on duct diameter. Flex duct 05 on most metal duct calculator round metal pipe 06 on most metal duct calculators field duct sizing chart rectangular sheet metal duct 07 on most metal duct calculators.

Rectangular duct is rounded up to the nearest 1 4 inch. Enter duct airflow cfm duct velocity fpm duct length and the number of bends. Read round duct diameter inches and friction loss per 100 of duct inches of water. Use the online duct calculator see references and calculate the needed flex duct size.

Enter round duct diameter. Equivalent duct calculator round vs rectangular. Friction loss calculator for sheet metal ducts. Enter air flow and its velocity in air duct sizing calculator to find the diameter of duct size.

Read friction loss inches of water and duct velocity fpm. In wg duct tel. Other hart cooley mobile tools. Friction rate velocity friction rate.

This online air duct calculator is used to calculate the velocity of air flow feet per minute fpm and feet per second fps through any shaped circle square or rectangle ductulator with either diameter sides or area. Air duct also termed as ductulator is a passage that is used to provide fresh air into rooms buildings etc air ducts may be in circular square and in rectangular shapes. Input the required cfm in the box below that. Enter round duct diameter inches duct airflow cfm duct length and the number of bends.

Friction loss calculator for flexible ducts. Metal ductboard flex size by. Enter the desired length of the rectangular duct.