The Net Zero Energy Residential Test Facility (NZERTF) was constructed at the National Institute of Standards and Technology (NIST) to support the development and adoption of cost-effective net zero energy designs and technologies. The 250 m2 two-story, unoccupied NZERTF, built in 2012, had the following design goals: meeting the comfort and functional needs of the occupants; siting to maximize renewable energy potential; establishing an airtight and highly insulated building enclosure designed for water and moisture control; providing controlled mechanical ventilation; and installing highly efficient mechanical equipment, lighting and appliances. The NZERTF achieved its goal of generating more energy than it consumed during its first year of simulated occupancy by a single family, despite a severe winter. The airtightness goal was achieved through detailed envelope design, careful construction, and during- and post-construction commissioning. The NZERTF is one of the tightest residential buildings in North America with a whole building pressurization test result of roughly 0.6 h-1 at 50 Pa. The ventilation goals were met with a heat recovery ventilator sized to comply with ASHRAE Standard 62.2-2010, which corresponds to roughly 40 L/s or 0.1 h-1 for this building. Low indoor contaminant levels were achieved through the careful selection of building materials. This paper describes the design and construction methods used to achieve such a tight building as well as the performance measurements made to verify that the building achieved its ventilation and indoor air quality (IAQ) goals.
Air Media Magazine
Net-Zero Energy, Ventilation, contaminant levels, airtightness, building envelope, indoor air quality.