The net-zero, 16,800 square foot Putney School Field House, first occupied in November 2009, includes a gym and spaces for other recreation, health and socializing. The Field House is located at the Putney School, in Putney, VT, a rural area with approximately 6,700 heating degree-F days. This building incorporates micro-load enclosure design, daylighting, passive solar gain, and demand controlled ventilation to minimize loads. Heating is provided by multi-split, Variable Refrigerant Volume (VRV) air-source heat pumps without a back-up heating system. Ventilation is variable volume from a central enthalpy wheel energy recovery ventilator serving CO2-controlled VAV terminals in each space. The building is not airconditioned but both automatic and manual natural ventilation for passive cooling are incorporated. A 37 kW tracking PV array provided more electricity in the first year of operation than the building consumed for all services. The building is on track for a LEED 3.0 Platinum rating.
Building statistics and first year energy data, including sub-metered heat, ventilation, lighting and hot water, measured parasitic loads and a discussion of why air-source heat pumps were chosen will be used to present this case study of a netzero building in a cold climate. Lessons learned during commissioning and first year operation will be discussed, including challenges relating to building net-zero in terms of cost, marketplace availability of components and first year operation issues.