While performing a retro-commissioning process for an 870,000 ft2 outpatient hospital in the southeastern United States, dozens of Energy Conservation Measures were identified and presented to the facility managers. The facility manager had a modest budget to address these ECMs, and required that each ECM must demonstrate a payback within three years.
Early in the investigation process it was noted that the facility operated at a constant setpoint, 24/7, despite the fact that the majority of the facility was only occupied during standard business hours. This operating strategy was due to two factors:
First, the operations team assumed that by scheduling the equipment, the building would be extremely hot and humid the following morning, and they would lose control of the space conditions. The retro-commissioning team eased these concerns by describing a schedule/setback process that allows the units to shut down and only enable if space temperatures exceeds unoccupied setpoints. We then implemented a schedule on a test unit. Once the test proved successful, the full ECM was allowed to proceed.
Second, the facility was operating inadequate equipment. At the time of the initial investigation most of the AHU Variable Frequency Drives (VFDs) were not able to function properly, ultimately causing the units to continuously operate at 100% speed. Due to the high cost of installing VFDs, the operations team did not have the budget to replace the drives on their own.
However, by demonstrating the potential incredible savings that could be achieved by implementing an occupancy schedule, we were able to secure funding to cover the cost of the VFDs and to modify the operating schedules – all while demonstrating an estimated simple payback of 1.3 years.
Making better decisions and smarter investments
According to the US Energy Information Administration, the United States consumed about 97 quadrillion (1015, or one thousand trillion) Btu in 2016. Of that extraordinary amount, office buildings consume approximately 20%. That is enough energy to power 2.6 billion homes for a year.
In the Metro Washington, DC market alone, there is approximately 470 Million square feet of existing buildings (10,000 buildings) compared to the 12 Million square feet of new construction (160 buildings) built in 2016. Due to the sheer volume of existing buildings and the energy they consume, implementing an energy audit or retro-commissioning process is a smart, cost effective solution for any existing building.
No matter the size or use of your property, the knowledge that comes from an audit or retro-commissioning allows the facilities team to make better decisions and smarter investments. Whether your goal is to operate a more efficient facility, lower operating costs, or decrease your carbon footprint, an energy audit and retro-commissioning process are excellent ways to achieve your goal.