HVAC Systems · Tools

Manometer

An instrument that measures pressure differential, typically in inches of water column (in. wg) for HVAC work. Used to measure duct static pressure, gas manifold pressure, draft pressure in flues, and filter pressure drop. A pro's primary diagnostic for airflow problems — total external static pressure above 0.5 in. wg on a typical residential system means the ductwork or filter is over-restricting the blower.

Related terms

• Static Pressure
• CFM
• ECM Blower
• Air Filter
• Manual D
• HVAC Multimeter

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