Hvac Duct Area Calculation Formula

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.

Hvac duct area calculation formula.

Standard autocad drawings shows the width and height of duct at various regions where as length should be taken out using a hand scale by measuring the duct at each positions. Beauty and health engineering finance life mathematics science. To calculate the rectangular duct area we need height width and length. Then we find the area ratio using the formula diameter out squared divided by diameter in squared.

Then you have to convert the outside of that form its perimeter and length into a workable flat surface and convert the area of that flat surface to square feet. The equation assumes that the ambient barometric pressure is constant at a value of 29 15 hg since the change in wetbulb temperature is very insignificant with changes in the ambient barometric pressure. The following equations are used to calculate the wetbulb temperature of air given the drybulb temperature and relative humidity. Converting an area to square feet would seem simple unless the area is spread over a form with height width and depth.

Then to get area in meter square use the equation. It s a simple enough process as long as you remember the formula. Online calculator to calculate the area of a rectangular duct.