ESCO Air Conditioning Practice Exam 2025 – The All-in-One Guide to Exam Success!

Fan airflow pressures are typically measured in inches of water column. This unit of measurement is appropriate for evaluating air pressure differences, especially in HVAC applications. The reason for using inches of water column is that it provides a suitable scale for the relatively low pressures encountered in air handling systems. Specifically, this measurement is effective in indicating the static pressure within ductwork and the performance of fans and blowers.

Inches of water column are particularly advantageous in HVAC because they convey the pressure exerted by airflow in a way that reflects the performance characteristics of air conditioning and ventilation systems. This is critical when assessing system efficiency, diagnosing issues, or designing duct systems to ensure optimal airflow and pressure balance.

Other units, such as feet or inches of mercury, are more commonly used in different contexts, such as measuring atmospheric pressure or in barometric applications. Pounds per square inch is a unit more suited for measuring higher pressures, like those found in hydraulic systems rather than the typical airflow pressures within HVAC systems.