VLVS includes equipment with varying load and varying hours-of-use, as depicted below. In this case, the total number of hours of operation and the number in each percentage load bin are unknown. Load curves may be developed as described above for VLTS.
Examples of equipment with VLVS operating characteristics include:
1. Variable air volume air handling unit (AHU) under thermostat control
2. Hot-water boiler serving reheat coils in zones
3. Chilled water system maintaining a chilled water supply set point reset schedule
4. Industrial compressed-air system variable frequency drive (VFD) compressor
5. VFD controls on an irrigation pump