What is the maximum operating pressure allowed in an air duct system?

The maximum operating pressure allowed in an air duct system is critical for ensuring safety and efficiency. In HVAC systems, static or internal pressure in ductwork is typically measured in inches of water column (iwc).

The correct answer reflects standards that ensure the structural integrity of the ductwork and prevention of failure or air leaks. An operating pressure of 10.0 iwc is generally accepted for many commercial and residential systems, allowing for a balance between performance and safety. This level of pressure is adequate to support proper airflow and system efficiency without risking damage to the duct materials, which can occur at higher pressures.

Higher pressure systems may be used in specific industrial applications, but they come with increased risks and require more robust materials and design considerations. The chosen standard helps maintain a safe and effective HVAC system that meets typical building requirements.