Static pressure controller(s) sense what type of pressure?

The correct choice indicates that static pressure controllers sense the static pressure exerted against the duct in all directions. Static pressure is defined as the pressure in a fluid caused by its weight and is measured in a system that is at rest or in a steady state. This type of pressure does not change when the fluid is moving, as it represents the potential energy in the system.

In HVAC systems, static pressure is crucial for maintaining proper air distribution and balanced airflow. Controllers that sense this type of pressure can help regulate fan speeds or dampers based on real-time readings, ensuring that air is delivered efficiently throughout the system. By monitoring static pressure, these controllers also help prevent issues such as over- or under-pressurization within ductwork, which can lead to inefficiencies and comfort issues in the conditioned space.

Understanding the role of static pressure controllers is essential for effectively designing and maintaining HVAC systems, as they directly influence both energy efficiency and indoor air quality.