Question

In an exhaustive ventilation system an evasee is used to

• A. Reduce static head of the fan
• B. Reduce shock loss at the fan inlet
• C. Recover velocity head lost to atmosphere
• D. Improve air power of the ventilation system

Hint:

Evasee = Energy recovery from outlet air velocity in ventilation systems.

Answer 1

The Correct Option is C

An evasee is a diffuser attached to the outlet of an exhaust fan. Its primary purpose is to recover part of the kinetic energy (velocity head) of the air discharged to the atmosphere, converting it into static pressure, thereby improving system efficiency.