Signifying Hotchkiss School’s commitment to becoming carbon-neutral, this facility is a living classroom for students that burns sustainably-harvested woodchips to heat the campus. Its undulating green roof blends into its surroundings while standing out as an iconic landmark.
Centerbrook designed this Central Heating Facility to heat all 1.2 million square feet of the 85 buildings that comprise the campus. It burns woodchips and replaces an oil-fired boiler plant, reducing greenhouse gas emissions by a third to nearly a half. The building houses two biomass boilers. Four truck bays feed wood chips into a 17,500-cubic-foot storage bin capable of supplying a week’s worth of fuel.
Two Messersmith boilers operate at 80 percent efficiency and generate 20 million BTUs per hour burning waste wood acquired from sustainably harvested local forests certified by the Forest Stewardship Council. The woodchips replace 150,000 gallons of fuel oil per year and cut emissions overall, most dramatically sulfur dioxide, by more than 90 percent. Waste ash from combustion is collected for use as fertilizer for the school’s gardens, and an electrostatic precipitator removes 95 percent of particulate matter from emissions.
Woodchips collected from managed timber stands are considered a “carbon neutral” fuel by the International Panel on Climate Change because the CO2 produced by their use is reabsorbed by the ecosystem through regrowth of the forests where they originate. Biomass heating is expected to reduce Hotchkiss’ carbon footprint by more than 6 million pounds of CO2 a year. There are currently 80 biomass facilities in 20 states.
This facility was one of only three LEED Certified power plants in the country at the time it opened. The vegetated roof combines with a bioswale/rain garden system to absorb rainwater and filter runoff before returning it to the ground.
Tours of students and community groups have access to a mezzanine balcony that overlooks and circumnavigates the boiler room. Wall-mounted displays and a series of interactive computer consoles track performance data. Outside, a nature path (below) passes by the vegetated roof on its way to a rain garden, bioswales and nearby wetland.
