Add supply and return static readings to get total external static pressure in inches of water column or pascals, then compare with the rated maximum.
Total external static pressure is the resistance the blower works against outside the unit. Higher than rated usually means less airflow. Check the filter, coil and dampers first; they are free or cheap to inspect.
Estimates based on your inputs. Always verify against the manufacturer's data and the codes that apply where you work.
Describe the symptom and your readings. Brixon helps you work through the free, quick checks first, then the deeper tests. It can be wrong, so confirm on the equipment.
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