After a major retrofit that included HVAC upgrades and lighting automation, Caterpillar’s headquarters will save about $800,000 a year in energy costs.
The retrofit of its Peoria, Ill., headquarters resulted in a 46 percent drop in annual energy consumption, said Tom Gerike, Engineering Project Team Leader.
Previously, the building’s annual energy usage of electricity and natural gas was 111,591 MMBTU. Now, it uses 60,622 MMBTU, he said.
Caterpillar added direct digital controls (DDC) to 800 zones of the building, allowing for precise control of each zone, and preventing simultaneous heating and cooling of adjacent zones.
The building is saving money with variable fan volume for the HVAC system.
“With the variable volume system, this allowed the interior building zones to have their heating coils disabled,” he said. “All of the heating is done by the exterior zones.”
An upgrade to controls for the chiller plant is helping maximize pumping efficiency, he said.
Caterpillar was able to gain efficiencies by setting up a seasonal schedule for building systems, Gerike said.
“There was no night setback in place for HVAC equipment or for lights,” he said, adding that consistent setpoints were established at 70 degrees in the heating season and 76 degrees in the cooling season.
Also, Caterpillar increased training for building operators for how the DDC system was programmed and how the overall system was to function to optimize energy savings. A building operating plan was developed to ensure consistent operation of building systems. Increased maintenance of the existing building systems was performed, including the installation of new VFDs, the installation of new control valves, and the installation of new damper actuators, he said.
Air handler control algorithms were re-written to optimize energy efficiency, he added.
For lighting automation, the new system has smart breaker panels controlled by a lighting schedule with pushbutton overrides for common areas. Also, motion sensors were installed into private offices and conference rooms.
As a result of the upgrades, the building earned LEED Gold for existing buildings, according to a press release.