Helen Keller Elementary School
The new $16.4M, 56,600 square foot Helen Keller Elementary School replaced the old school that was constructed in 1968, and consists of 22 classrooms that support 350 students. This project received the William W. Caudill Citation Award and Learning by Design's 2014 Grand Prize Award.
Automatic daylight harvesting techniques are employed in each classroom to reduce the artificial lighting levels in response to natural sunlight, saving significant lighting-use energy. A roof-mounted, 10kW, photovoltaic (PV) system is installed and tied into the building's electrical distribution system. Provisions were made to provide a kiosk monitor to report PV production and current meteorological conditions as a visual aid for teaching and learning PV technology.
The HVAC system consisted of a two-pipe hydronic system, producing hot water for a mixture of Variable Air Volume (VAV) and constant air volume zones. Heating water is produced by high efficiency gas fired boilers and distributed throughout the building with a variable flow pumping system. The gym, commons, kitchen, and stage are served by constant volume air handling units with hot water coils, exhaust fans, and air side economizer, delivering air to an overhead air distribution. The classrooms are served by a VAV displacement ventilation system. Each classroom has a terminal box with hot water reheat, displacement ventilation devices placed low in the space with a high return for ventilation and air distribution efficiency, and hot water finned tube heaters at the exterior walls to heat the space. The VAV central air handlers employ air side economizer, a hot water coil, and a unique energy recovery system that consists of a glycol runaround loop with a water-to-water heat pump in the circuit located between the supply and exhaust side coils. This allows energy to be recovered from all building exhaust air without crossover as well as providing cooling capability on days when the air side economizer is not viable.