N.Y. Private School Focuses on HVAC Efficiency, Energy Conservation

NEW YORK — Vegetated roofs, waterless urinals and rainwater cisterns are just a few of the sustainable design elements that make the new Ethical Culture Fieldston School middle school a candidate for silver LEED certification.


The $75 million campus expansion project inludes a 47,000-square-foot middle school, a 38,000-square-foot gym, a 14,000-square-foot natatorium and an additional 34,000 square feet of renovated space — all designed with an eye toward sustainability.


New York architectural firm Cooper Robertson & Partners focused on water conservation and energy management to ensure an environmentally responsible school, part of Ethical Culture’s philosophy. The campus was also renovated using several recycled construction materials.


Stormwater cisterns, combined with vegetated roofs, help manage rainwater runoff for irrigation and filtration, while waterless urinals help reduce water use inside buildings. The green roof, which is also designed to provide insulation in winter and reduce heat in summer, is open to classes studying the use of natural plants with green roof systems.


To conserve energy, the school uses an energy-efficient HVAC system that recycles energy and recovers heat from classroom buildings, the gymnasium and the natatorium. As part of the HVAC assembly, a 22,000-cfm dehumidifier from Montreal-based Dectron Inc. keeps the swimming pool and spectator area in a constant 50 percent humidity, while recovering enough energy to provide free pool water heating for the school.


The system is also designed to ensure that if 100 percent pool water heating cannot be achieved during extremely cold weather, a 540,000-Btu high-efficiency backup boiler will engage to provide heating.


A 20,000-cfm outdoor air system installed by ASM Mechanical Systems, of New York, utilizes heat pipes to recover energy from the middle school and gymnasium exhaust systems to save both heating and cooling energy. Architects also specified low-E glass glazing on windows to improve thermal efficiency.