Cfm Per 8 Inch Duct

Just under 500 fpm vel.

Cfm per 8 inch duct.

Is much quieter. If you double the cfm to 320 cfm. Vivosun 8 inch 720 cfm inline duct fan ideal for controlling hot and humid conditions in grow tents rooms. Looking at my chart i see 420 cfm requires a 8 inch flex duct with a velocity of 1190.

Duct system sizes and airflow quick chart created date. 09 to 10 pressure drop per 100 el cfm round no. Like regular hvac duct flex duct work needs to be sized appropriately in order to flow the air volume which is measured in cubic feet per minute cfm correctly. Imo too high a velocity for a residential branch run that we.

Ordered it and received it in a few days very quick delivery. Sl rectangular td 50 5 8 x 6 75 5 8 x 6 100 6 8 x 6 3 x 10 110 125 6 8 x 6 3 x 12 140 150 7 8 x 6 3 x 14 160 175 7 8 x 6 200 7 8 x 6 250 8 6 x 10 8 x 8 6 x 12 300 9 6 x 10 8 x 8 6 x 12 350 9 6 x 10 8 x 8 6 x 12 400 9 8 x 10 8 x 8 6 x 12. Without it there would be tons more labor and material to make that final connection. Installed it easily was doing a relocation of fan for a different renovation.

A typical 3 ton hvac system needs a metal duct about 16 inches round to deliver 1300 cfm. 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. The following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct. Design cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12 90 8x4 110 6x6 160 6x8 215 6x10 270 6x12 120 10x4 160 8x6 230 8x8 310 8x10 400 8x12 150 12x4 215 10x6 310 10x8 430 10x10 550 10x12 180 14x4 270 12x6 400 12x8 550 12x10 680 12x12 210 16x4 320 14x6 490 14x8 670 14x10 800 14x12 240 18x4 375 16x6 580 16x8 800 16x10 950 16x12 270 20x4 430 18x6 670 18x8 930 18x10 1100.

Flex duct allows easy connection from the main duct trunk to the hvac grille. Yields 0 02 friction loss. Could your information be wrong and the rating be airflow in feet per second. Over a 25 run you would get.

Good residential design usually uses velocities of 700 to 900 fpm for supply and 600 to 700 fpm for return. Fan works very well. This equal friction method of duct sizing should be adequate for normal residential furnace. Everything else the same above.

A cfm of 1220 requires a 12 inch duct flex using rigid 1350 cfm needs 16 inch duct. I usually size duct by friction rate loss velocity per cfm on a duct run not by esp. Equivalent length at a velocity of 925 feet per minute. 320 cfm in 8 duct yields 19in.