What is the maximum static pressure for most residential furnaces with a PSC?

For most residential furnaces utilizing a Permanent Split Capacitor (PSC) motor, the maximum static pressure typically is around 0.5 inches of water column (WC). This value is significant as it represents the limit to which a PSC motor can efficiently operate without sacrificing performance or risking overheating.

Exceeding this pressure can lead to reduced airflow, increased strain on the motor, and potential system failures. PSC motors are generally designed for low pressure applications, making this static pressure level a critical consideration in system design and operation to ensure optimal performance and longevity of the HVAC system.

In contrast, values higher than 0.5 WC might indicate systems that are more suited to other types of motors capable of handling increased pressures, such as variable speed motors. Thus, understanding the limitations of PSC motors helps technicians determine appropriate designs and troubleshoot issues effectively.