Performance-Based Maintenance (PBM) is servicing equipment according to measured operational parameters with procedures to diagnose suboptimal performance and improve energy efficiency.

This case study demonstrates how servicing unitary HVAC systems based on field-measured operational energy efficiency produced documented energy savings. Lessons learned offer field-proven implementation guidance for including PBM in routine maintenance for unitary HVAC to realize substantial benefits.

Results show measured energy efficiency as EER and IEER were improved by about 30 percent on average in the group of selected systems that were serviced, compared against an efficiency decrease in units that were not serviced. Cost effectiveness of Performance-Based Maintenance (PBM) was analyzed in terms of payback period and savings-to-investment ratio (SIR) of implementation cost. Annual savings from servicing the HVAC systems selected for PBM was 21 percent. Modeling indicates a PBM program will produce energy savings of $81,000 to $116,000 per year on an estimated hard implementation cost of $114,000 per service cycle of 2-years, for 60 HVAC systems of average size 12-tons at $0.10/kWh electric rate. Projected simple payback period is 6 to 8 months with an SIR of 1.5 to 2.3 across a range of climates and electric rates, meeting suitability criteria as an ECM under most UESCs and ESPCs.

A qualitative assessment indicated positive acceptance of PBM by the personnel who participated in the program, shaded by concerns about adequate resources to support proper unitary HVAC maintenance. Energy manger, HVAC technician and public works director comments are shared and discussed in this presentation by Mike West, Building Systems Scientist, Advantek Consulting Engineering.