Monitoring Based Commissioning (MBCx) uses continuous sensor data and performance analytics to verify that HVAC systems operate as designed, enabling commissioning without physical tests or equipment interruption. Rather than conducting time-consuming manual tests that may require temporary operational changes, MBCx analyzes months of operational data to confirm control sequences, identify setpoint errors, and detect sensor failures. This approach reduces commissioning cost by 40-50 percent while validating real-world performance under actual occupancy conditions.
Technical Details
MBCx platforms process 1-minute interval data from 50-500 BAS points, applying statistical analysis and rule-based algorithms to verify setpoint compliance, equipment sequencing, and energy performance. Analysis typically spans 3-6 months of data collection before conclusions are drawn. Systems flag deviations from design specifications with high confidence when sensor quality meets ASHRAE accuracy standards of plus/minus 2 percent.
Applications in HVAC
MBCx verifies economizer damper logic, terminal unit reheating behavior, chiller load sharing, and boiler cycling. Programs identify missing setpoint resets, incorrectly programmed occupancy schedules, and sensor calibration drift that would escape notice during spot-check commissioning.
Practical Significance
Non-disruptive verification reduces tenant impact and eliminates scheduling conflicts common with traditional commissioning. MBCx costs $15,000-$30,000 per building versus $40,000-$60,000 for conventional comprehensive commissioning.