Hvac Duct Area Calculation Formula

Measure the distance across the duct in inches then multiply by 3 14159 if the duct is circular to find its circumference in inches.

Hvac duct area calculation formula.

Then we find the area ratio using the formula diameter out squared divided by diameter in squared. A good quality hvac engineer needs to be familiar with complex numbers and calculations. A complete guide to hvac formulas. Work force energy exerted x distance.

To calculate the rectangular duct area we need height width and length. Width 1 height 1 width 2 height 2 x length x qty area if up down taper formula. Width height x 2 x length x qty area. Numbers play a large part in the hvac industry.

Width 1 height 1 width 2 height 2 x length offset x qty area offset formula. Hvac duct quantity weight and area calculator download hvac duct quantities weight and area calculation sheets. When the quantity take off is completed take 10 extra of duct this will resolve the quantity assumption. The numbers involved are more complex than the difference between 35 and 95 degrees.

Mercury 1 psi. Then measure the length of the duct in inches and multiply by the circumference. We take our values from our table and use 3 5m s divided by 4m s to get 0 875 for the velocity ratio and we use 0 26m squared divided by 0 33m squared to get 0 62 for the area ratio. This is the number of square inches in the duct area.

Approximately 2 inches hg. Ton of refrigeration the amount of heat required to melt a ton 2000 lbs of ice at 32 f. B height of other duct side inches equivalent round duct size for a rectangular duct equivalent round duct size for a rectangular duct can be expressed as deq 1 3 x a x b 0 625 a b 0 25. Length r w 2 x 3 14 x degree 180 taper formula.

As with any mathematical solution it is easy when you know how. Home hvac 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. The velocity in a rectangular 0 5 m x 0 5 m duct with air flow 1 m3 s can be calculated as vm 1 m3 s 0 5 m 0 5 m 4 m s air flow velocity calculator si units.