"We initially installed two 2MBtuh Benchmark units to handle the 118,084-sq-ft building," said Stephen Novell, supervisor of mechanical maintenance at the Fort Wayne Community School System. "We kept one of the old boilers because a portion of the building remained on a steam system. In 2002, we pulled the last steam boiler and converted the remainder of the building to hot water. At this point, we also installed a third Benchmark unit. It provided the capacity cushion we wanted while adding to the efficiency profile of the overall heating plant."
To fully leverage the unit's overall efficiency, Novell utilized AERCO's Boiler Management System, which ensures that the three Benchmark units functioned as a single system. The system regulates the units to operate in tandem, providing them with precise firing instructions that ensure maximum efficiency. It is more efficient for the three boilers to run at 30% input than for two to run at 45%, or for one boiler to run at 90% of capacity. The system also consistently rotates the lead boiler in the plant so that each unit receives approximately the same amount of work over the course of the season. This prevents undue wear on any single unit.