For a flexible duct with 10 inch diameter and 10% compression, what would be the effective length of the duct?

To determine the effective length of a flexible duct with a diameter of 10 inches that has been compressed by 10%, it's essential to understand how compression affects the length of the duct. When flexible ductwork is compressed, it loses some of its original length because the material folds in on itself.

The original, uncompressed length of the duct is typically assumed to be the full length indicated (in this case, 10 feet). When you apply a 10% compression to this length, you are essentially reducing it by 10% of the original measurement.

To calculate this, you take 10% of the original length of 10 feet. That means:

10% of 10 feet = 0.1 x 10 feet = 1 foot.

Now, subtract this compression from the original length:

10 feet (original length) - 1 foot (compressed length) = 9 feet.

Thus, the effective length of the duct after taking into account the 10% compression would be 9 feet. This method clearly demonstrates how duct length is affected by compression and provides the correct effective length for practical applications in HVAC systems.