Pathfinder provided a study and designed replacement of existing chillers for the eight-story 186-bed Strozzi Building, which provides inpatient 24 hours a day, seven days a week. Energy savings, incentives and maintainability were key design considerations. In order to meet the 400-ton cooling load the new $1.1 million plant design included multiple air cooled chillers netting 600-tons and providing capacity redundancy chiller failure. The layout is four 150-ton chillers with all chillers using environmentally safe refrigerant in accordance with The Clean Air Act.
In order to maximize the energy efficiency of the building, Pathfinder selected high-efficiency chillers with full load and part loads that exceed the thresholds laid out for air-cooled chillers. Design specifically focused on part load efficiencies for the chiller selection, at 8% improvement over code IPLVs, as the majority of run hours will fall in part load conditions. The control system sequences the chillers and runs multiple chillers at part load in order to maximize the energy efficiency of the plant.
National Grid provided a rebate incentive for chillers that exceed the efficiencies in the New York State Technical Resources Manual (2019). These rebates were based on the type of chiller and the step improvement in the part load IPLV’s over National Grid tabulated values. The rebates for the 100% design chiller selection is approximately $19,000.