ESCO Air Conditioning Practice Exam

Fan airflow pressures are usually measured in

1. Feet of mercury

2. Inches of mercury

3. Inches of water column

4. Pounds per square inch

The correct answer is: Feet of mercury

Fan airflow pressures are typically measured in feet of mercury rather than the other options listed. Feet of mercury is a common unit of measurement for pressure in mechanical systems such as HVAC or ventilation systems. It is derived from the inches of mercury unit used to measure barometric pressure and is often used to indicate a difference in pressure between two points. Inches of mercury and inches of water column are also units for measuring pressure, but they are less commonly used in this context. Pounds per square inch is another unit for measuring pressure, but it is typically used to measure more moderate levels of pressure such as in a car tire. This unit would not accurately represent the low pressures typically associated with fan airflow.