Kroon Hall, the LEED® Platinum-certified home of Yale University's School of Forestry and Environmental Studies, was designed to be a model for sustainability, in support of the school's mission. Arup's scope for this non-laboratory academic facility included structural, mechanical, electrical and plumbing engineering; acoustic consulting; and lighting design.
The building's form was designed to take full advantage of passive, low-energy systems. Oriented east-west along the sun's path, Kroon Hall's exposed thermal mass, deep-set windows, and external shading control solar heat gain. Concrete was used throughout the building to provide thermal mass, minimizing temperature swings. When external conditions are suitable for natural ventilation, indicator lights prompt occupants to open their windows.
Four geothermal wells heat and cool the building, with conventional utility power available for emergency back-up. Kroon Hall's geothermal system is much larger than most. Four 1,639ft standing column wells reach down to bedrock, where water temperatures hover around 55 degrees. Groundwater is pumped up and its thermal energy extracted, then intensified by ground-source heat pumps. Once the water has performed its heating (or, in summer, cooling) function, it is returned to the same wells.
In winter, efficient air-handling units reclaim heat from exhaust air and transfer it to incoming air. In summer, a cooling system sprays water into the exhaust air to lower its temperature. A heat recovery system then transfers this coolness to the incoming air.
These and other measures result in an energy savings of approximately 58% compared to a similar building that does not exceed code requirements.
Kroon Hall's potable water use is 81% below the LEED baseline.