Comprehensive Energy Efficiency Treatment
Efficiency upgrades to energy management systems resulted in annual savings in excess of $500,000 with a simple payback of just 3 years.
OpTerra installed new high efficiency chillers under VFD control, modified AHU VFD, installed additional EMS controls, converted lighting fixtures to more efficient design, and modified VAV systems in an office building.
Two high efficiency 550-ton chillers replaced the existing 600-ton chillers that were approaching the end of their useful life. The new chillers operate under variable frequency drive (VFD) control. OpTerra made system and control modifications to the existing chilled water pump that allowed the pump to operate at a variable flow with reduced speed, saving energy. Additional controls and sensors for the single air handling unit (AHU) serving the twelve operating suites allows the zones to be isolated and the AHU VFD to reduce speed. The installation of additional energy management system controls allows the air handling fans serving the office areas to shut off during unoccupied periods.
Over 5,000 lighting fixtures throughout the hospital, including the parking garage, were upgraded to super T-8 technology, saving over 1.5 million kWh of lighting energy annually as well as reducing the cooling load. Installation of wall and ceiling mounted occupancy sensors, where appropriate, shut off lighting when the space was unoccupied. Lastly, the Medical Office Building, although designated as a variable air volume (VAV) system, was operating as a constant volume system due to failure of VAV boxes and controls. Through installation of VAV diffusers as well as new rooftop units with VFD fans and controls, the system was successfully converted back to VAV.
There are additional water and gas savings that result from these measures that make the total annual savings in excess of $500,000.