Air Duct Elbow Pressure Drop Calculator

This article details the calculation of pressure losses through pipe fittings and some minor equipment using the equivalent length method.

Air duct elbow pressure drop calculator.

δh 0 109136 q 1 9 d e 5 02 1. Pressure drop any method above initially determine the index run. These charts hold a lot of information. δh friction or head loss inches water gauge 100 ft of duct.

Calculations are possible only if javascript is activated in your browser. Pressure drop online calculator for small mobiles. The layout of the chart does vary a little depending on the manufacturer but in this example the vertical lines are for pressure drop per meter of duct. The strength of the equivalent length method is that it is very simple to calculate.

We can use them to find the pressure drop per meter the air velocity the volume flow rate and also the size of the ductwork. Elbows choose up to three different elbow types. Air velocity changes due to changes in duct sizes. Velocity pressure of 2 entering branch inches water.

Minor or dynamic losses in duct systems are pressure losses caused by. D e equivalent duct diameter inches. Standard air is defined as clean dry air with a density of 0 075 pounds per cubic foot with the barometric pressure at sea level of 29 92 inches of mercury and a temperature of 70 f. Q air volume flow cfm cubic feet per minute.

Sum of flows in branches 1 and 2 must equal flow rate in acfm input above. Pressure drop online calculator calculation of pressure drops of flowing liquids and gases in pipes and pipe elements laminar and turbulent flow. Minor or dynamic pressure loss in air duct system components can be. Change in air direction from elbows offsets and takeoffs.

Obtain other duct fittings pressure losses from manufacturers such as duct heaters dampers filters grilles coils etc. Selecting a fan to operate at conditions other then standard air requires adjustment to both static pressure and brake horsepower. For rectangular ducts the equivalent diameter must be calculated. Calculate the pressure loss of the duct fitting in a 600mm w x 200mm h duct with a radius of 600mm and a 90 bend angle.

Restrictions or obstructions in the air stream in outlet fans dampers filters and coils. Fittings such as elbows tees and valves represent a significant component of the pressure loss in most pipe systems. The weakness of the equivalent length method is that. Duct design fundamentals static pressure ps measure of the static energy of air flowing air which fills a balloon is a good example of static pressure equally exerted in all directions the atmospheric pressure of air is a static pressure 14 696 psi at sea level.