Flex Duct Cfm Calculator

Read round duct diameter inches and friction loss per 100 of duct inches of water.

Flex duct cfm calculator.

Input the required cfm in the box below that. Equivalent duct calculator round vs rectangular. Fpm is velocity in flex duct feet per minute. Sheet metal duct friction loss calculator.

Duct cross sectional area air flow rate and air speed are used in calculating the duct size. Enter round duct diameter. Cfm is flow rate in flex duct cubic feet per minute. Other hart cooley mobile tools.

In wg duct tel. Use the online duct calculator see references and calculate the needed flex duct size. Friction loss calculator for flexible ducts. 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.

Based on duct diameter. Data is based on straight runs of quietflex non metallic flexible air ducts as tested in accordance with the air diffusion council fd 72r1 test code and in accordance with ashrae 120 1999 method of testing to determine flow resistance of hvac. Enter round duct diameter inches duct airflow cfm duct length and the number of bends. Friction loss calculator for sheet metal ducts.

Rectangular duct is rounded up to the nearest 1 4 inch. Enter the desired length of the rectangular duct. 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. Read duct diameter inches and duct velocity fpm.

Equivalent diameter is the diameter of a circular duct with similar pressure loss as an equivalent rectangular duct. Include fittings in the duct tel enter either. Enter duct airflow cfm duct velocity fpm duct length and the number of bends. Select the duct type on the pull down menu.

Enter air flow and its velocity in air duct sizing calculator to find the diameter of duct size. The flex duct size may be different than the hard duct that runs to that room. 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. 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 friction loss inches of water and duct velocity fpm. Cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12. Click calculate and you will see the size of flex duct you need for that room.