What can high duct static pressure indicate in a heating system?

High duct static pressure in a heating system typically indicates insufficient airflow. When there is high static pressure, it suggests that air is not flowing freely through the ducts, which may result from several factors such as clogged filters, duct obstructions, or undersized ductwork. Insufficient airflow not only hinders the efficiency of the heating system but can also cause overheating of the furnace and lead to potential system failure.

In contrast, excessive airflow would produce low static pressure since it allows air to move easily through the duct system. A balanced system would show normal static pressure levels, indicating that the airflow is appropriate for the system's design and capacity. Therefore, when encountering high duct static pressure, it is crucial to investigate the airflow dynamics and ensure the system is operating optimally.