As an equation this is written.
Hvac duct area calculation formula pdf.
5 cfm fpm x area given any two of these three quantities the third can be readily determined.
Sample office building space area ft2 hvac area ft2 1st floor 10 000 8 000 2nd floor 10 000 8 000 total 20 000 16 000 4 k k b n a l 5 ç.
Download hvac duct measurement excel sheet xls 11 02 2018 04 09 00 pm this excel sheet is for hvac duct measurement like duct weight duct area and all calculation related to ductwork like hanger supports and duct insulation.
Square feet air volume in cfm can be calculated by multiplying the air velocity by the cross sectional area of the duct in square feet.
The volume flow rate of air is the product of the cross sectional area of the duct through which it flows and its average velocity.
How to calculate area.
The floor input is only used to calculate the roof area which is used in the heating load calculations.
Hvac duct quantity weight and area calculator.
6 ù ß â â å æ l8 000 b p 6.
Rectangular duct round duct.
Air conditioning formulas 1 btu amount of heat required to raise or lower temperature of one pound of water 1of 1 ton refrigeration 12 000 btu h 200 btu min 1 watt 3 412 btu h 1 horsepower 2545 btu h 1 lb 7000 grains 1 ft head 0 433 psi 1 square foot.
When the quantity take off is completed take 10 extra of duct this will resolve the quantity assumption.
Fpm cfm area area cfm fpm.
Q volume flow rate cubic feet per minute or cfm a p duct cross sectional area ft2 d2 576 where d is diameter in inches.
Duct size or cross sectional area.
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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.
To calculate the rectangular duct area we need height width and length.
A l x w a 𝜋𝐷 2 4 or r2 return air grilles net free area about 75.
3 phase voltage unbalance 100 𝑥 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑑𝑒𝑔.
Single number for the hvac building area value.
