A pressure sensor measures static, dynamic, or differential pressure in HVAC systems to monitor equipment performance, verify proper airflow, and control fan operation. Pressure sensors are essential for filter clogging detection, ductwork balance verification, and demand-reset strategies. Typical commercial sensors measure ranges from 0-2 inches water column (WC) with ±5% accuracy.
Sensor Types and Specifications
Diaphragm pressure sensors use capacitive or piezoelectric elements to generate 4-20 mA output signals proportional to pressure. Differential pressure sensors with dual ports measure pressure drop across filters and determine clogging conditions (typical limit: 0.5-1.0 inches WC). Industrial-grade sensors withstand -40 to 185°F and output signals over 1,000+ foot distances without degradation.
Control Applications
Duct static pressure sensors in return plenums enable proportional fan speed control to maintain constant 1.0-1.5 inches WC setpoint, reducing fan energy 20-30%. Filter differential pressure sensors trigger maintenance alerts at 0.5 inches WC. Supply air pressure measurement verifies balanced airflow to multiple zones and detects equipment failures affecting system performance.