What does the equivalent length of a duct fitting mean?
What does the equivalent length of a duct fitting mean? Is is the length of straight duct that would have a pressure drop equal to the pressure drop through the fitting.
How do you calculate equivalent duct length?
Equivalent Duct Length is the sum of the straight pipe that is concealed in the wall plus any 45 or 90 degree elbow deductions.
What is the equivalent length for pipe components?
The definition of the Equivalent Length of a pipe fitting is the length of pipe of the same size as the fitting that would give rise to the same pressure drop as the fitting.
What is the equivalent length of a 90 degree elbow?
For a 90 degree elbow, the equivalent length is 30D or 30 times the diameter of the pipe in feet. Hence for a 16 inch long radius elbow, the equivalent length of this elbow is 30 x 16/12 = 40 feet. Of course, if there are 8 elbows in the system, the total equivalent length will be 320 feet.
How long can an air duct be?
“If your ductwork is over 15 years old, you probably should replace it. Ductwork has a maximum lifespan of 20-25 years. By 15 years, however, it begins to deteriorate, significantly reducing your HVAC system’s efficiency, so replacement is the prudent option.”
How long can a AC duct be?
If you choose well, you can be at 10 or 20 feet of effective length. If you choose that smooth mitered elbow, however, you end up with 75 feet.
How long should ducts be?
The lengths of straight sections of duct add up to 36 feet for the supply side and 13 feet for the return side. The fittings add up to 290 feet and 85 feet respectively. This is typical. Fittings dominate when it comes to using up the available static pressure, so you have to choose them carefully.
What is equivalent length method?
The equivalent length method (The Le/D method) allows the user to describe the pressure loss through an elbow or a fitting as a length of straight pipe. This method is based on the observation that the major losses are also proportional to the velocity head (v2/2g).
How far can I run duct work?
Question: How far can you run ductwork? Answer: You can run ductwork 10 or 20 feet of effective length if it is of good quality. However, if you go with the smooth mitered elbow, you’ll wind up 75 feet.