What tool is commonly used to measure air flow in duct systems?

The common tool used to measure airflow in duct systems is the anemometer. An anemometer is specifically designed to measure the speed of air in a duct or open environment, which can then be converted to determine the airflow rate in cubic feet per minute (CFM) based on the duct cross-sectional area.

This tool plays a crucial role in HVAC applications, as proper airflow is essential for system efficiency, comfort in indoor environments, and ensuring that heating and cooling systems operate effectively. By measuring airflow, technicians can diagnose issues such as blockages, improper system sizing, or imbalances in the ductwork.

In contrast, other tools listed serve different purposes: a manometer measures pressure, a thermometer measures temperature, and a hygrometer measures humidity. None of these tools provide direct measurements of airflow, illustrating the specific utility of the anemometer in HVAC systems.