Which measurement indicates air pressure in duct systems?

Static pressure is the correct measurement that indicates air pressure in duct systems. In the context of ductwork, static pressure refers to the pressure exerted by air within the ducts on the walls of the ducts and is a key component in understanding how air flows through a system. It is crucial for ensuring that air is delivered efficiently to different areas of a building and for assessing the performance of HVAC systems.

Static pressure is significant for identifying how well the air distribution system is functioning. When static pressure is measured, it reflects the resistance to airflow caused by the ductwork, fittings, and any obstructions. Properly maintained static pressure levels are necessary for achieving optimal airflow and maintaining comfort in conditioned spaces.

In contrast, velocity pressure measures the kinetic energy of moving air and is related to the speed of the airflow in the ducts. While dynamic pressure encompasses both the static and velocity pressures, it does not specifically indicate the air pressure within the ducts. Atmospheric pressure pertains to the weight of the air surrounding the Earth and is not relevant for the internal measurement of duct systems. Understanding these distinctions helps with diagnosing issues and optimizing the airflow within HVAC systems.