What safety mechanism is typically included in HVAC systems to prevent overheating?

The limit switch is a crucial safety mechanism in HVAC systems designed to prevent overheating, which can lead to serious damage or hazardous situations. It serves as a monitoring device that tracks the temperature within the system. If the temperature exceeds a predetermined safe level, the limit switch activates and shuts off the heating element or the system itself. This automatic disengagement helps protect both the equipment and the users by preventing excessive heat buildup that could result in system failure or fire.

While other mechanisms, such as thermostats, pressure relief valves, and fan controls, play important roles in HVAC systems, they serve different purposes. Thermostats regulate temperature by controlling the operation of the system based on the desired setpoint. Pressure relief valves are essential for managing system pressure to prevent over-pressurization but do not specifically target overheating. Fan controls adjust airflow for optimal efficiency and comfort but do not directly intervene in cases of overheating. Hence, the limit switch is the key component that directly addresses the safety concern of overheating.