Service & TroubleshootingQuestion 86 of 110
When measuring the actual airflow of an installed system, which measurement helps diagnose a restrictive duct system?
a.Refrigerant subcooling
b.Gas manifold pressure
c.Total external static pressure across the air handler
d.Condenser saturation temperature
Explanation
Measuring total external static pressure and comparing it to the blower's rating reveals whether ductwork, filters, or coils are too restrictive. High static pressure indicates undersized or dirty components limiting airflow. It is a key airflow diagnostic tool.
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