Can you please help me resolve this question question?An 8x12" register has the velocity of 300 FPM with the free area of 75% what's the quantity of air exiting the register?
First you determine the area of the duct, which in your case is 12" x 12" = 144 in2. Then you need to convert this to feet as we're looking for "Feet per Minute). 144 in2 / 144 in2/Ft2 = 1 Ft2. The normal formula is Velocity x Area = CFM, so we just work backwards taking the 2,000 CFM dividing it by the 1 Ft2 = 2,000 FPM of Velocity. To check your self put the values back into the original formula of 2,000 FPM x 1 Ft2 = 2,000 CFM. Hope that helps.
szoval a ventilator rpm kell megallapitanom appszolut nem tudom hogy alljak hozza jarmu sebessege 70 ml/h + korulbellul szel sebessege vagy iranya az atmero 120 vagy 127mm 10-12 lapatos turbina ki tud segiteni megkoszonom!
For air conditioning ductwork it's the same calculation. CFM in an air conditioning dict is based on the area of the duct and the velocity. CFM = Velocity x Duct Cross Sectional Area
Superb video sir, i would like to request if you can please make a same demonstration for round ducts also.
Thanks in advance 💓.
Thanks for the suggestion.
Great video ❤. Very informative
Glad it was helpful! Thanks for watching.
new on ventilation... why wouldn't we always choose the smaller diameter to get the highest velocity on the duct?
Higher velocities for the same volume CFM will cause the fan to work harder, causing an increase in energy consumption.
Can you please help me resolve this question question?An 8x12" register has the velocity of 300 FPM with the free area of 75% what's the quantity of air exiting the register?
Gross area would be 8" x 12" = 96 in2 x 75% free area = 72 in2 / 144 in2/ft2 = 0.5 ft2 x 300 FPM = 150 CFM
Great video!
Thank you
Great video! Thanks!
Glad you liked it! Thanks for watching.
Where did the 114 number come from?
144 is the equivalent square inches in a square foot. 144 Sq. Inches = 1 Sq. Ft
Where did the 144 come from
There are 144 in2 in a square foot. 12" x 12" = 144 in2
Can you help me with this 12 x12 duct 2000CFM what is the FPM ?
First you determine the area of the duct, which in your case is 12" x 12" = 144 in2. Then you need to convert this to feet as we're looking for "Feet per Minute). 144 in2 / 144 in2/Ft2 = 1 Ft2. The normal formula is Velocity x Area = CFM, so we just work backwards taking the 2,000 CFM dividing it by the 1 Ft2 = 2,000 FPM of Velocity. To check your self put the values back into the original formula of 2,000 FPM x 1 Ft2 = 2,000 CFM. Hope that helps.
szoval a ventilator rpm kell megallapitanom appszolut nem tudom hogy alljak hozza jarmu sebessege 70 ml/h + korulbellul szel sebessege vagy iranya az atmero 120 vagy 127mm 10-12 lapatos turbina ki tud segiteni megkoszonom!
Good luck. Thanks for watching.
Where 144 in2 come from?
12 inches x 12 inches = 144 in2. This is equivalent to 1 square foot.
how about aircon cfm calculate?
For air conditioning ductwork it's the same calculation. CFM in an air conditioning dict is based on the area of the duct and the velocity. CFM = Velocity x Duct Cross Sectional Area
Runolfsson Squares
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Glad you liked it. Thanks.