Air Duct Elbow Pressure Drop Calculator

Restrictions or obstructions in the air stream in outlet fans dampers filters and coils.

Air duct elbow pressure drop calculator.

Minor or dynamic losses in duct systems are pressure losses caused by. Selecting a fan to operate at conditions other then standard air requires adjustment to both static pressure and brake horsepower. The weakness of the equivalent length method is that. Q air volume flow cfm cubic feet per minute.

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. Calculations are possible only if javascript is activated in your browser. Velocity pressure of 2 entering branch inches water. 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.

Sum of flows in branches 1 and 2 must equal flow rate in acfm input above. This article details the calculation of pressure losses through pipe fittings and some minor equipment using the equivalent length method. 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. Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport ohio 43125 duct system design.

Air velocity changes due to changes in duct sizes. Obtain other duct fittings pressure losses from manufacturers such as duct heaters dampers filters grilles coils etc. Pressure drop online calculator for small mobiles. Minor or dynamic pressure loss in air duct system components can be.

Elbows choose up to three different elbow types. D e equivalent duct diameter inches. Change in air direction from elbows offsets and takeoffs. δh 0 109136 q 1 9 d e 5 02 1.

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. The major loss or friction loss in a circular duct in galvanized steel with turbulent flow can for imperial units be expressed. δh friction or head loss inches water gauge 100 ft of duct.

Pressure drop any method above initially determine the index run. For rectangular ducts the equivalent diameter must be calculated. This version is usable for browsers without javascript also. 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.