What do HVAC professionals typically use to measure air flow in ducts?

HVAC professionals typically use a flow hood to measure air flow in ducts because it is specifically designed to capture and measure the volume of air being delivered or exhausted through a duct system. A flow hood works by placing it over a vent or duct opening; it calculates the air flow based on the velocity of the air passing through it. This device is essential for ensuring that HVAC systems are operating efficiently and delivering the correct amount of air to each area of a building.

Other measuring tools, such as a manometer, are used to measure pressure differences in the duct system, which can indirectly indicate air flow but do not provide a direct volume measurement like a flow hood does. Amperage meters measure electrical current and are not related to air flow measurement. Thermometers are used for measuring temperature, which is also unrelated in terms of quantifying air flow in ducts. Thus, the flow hood is the most accurate and effective choice for directly measuring air flow in HVAC applications.