Small Changes Yield Large Results at NIST's Net-Zero Energy Residential Test Facility
Arthur H. Fanney, William V. Payne, Joshua D. Kneifel, Lisa C. Ng, Brian P. Dougherty, Tania Ullah, William M. Healy, Farhad Omar
The National Institute of Standards and Technology (NIST) has embarked on a multi-year project to establish that a residence can generate, through the use of renewables, the same amount of energy as it consumes while meeting the energy needs of a typical family. The Net-Zero Energy Residential Test Facility (NZERTF) was designed to be approximately 60 percent more energy efficient than homes meeting the 2012 International Energy Conservation Code (IECC) requirements. The thermal envelope minimizes heat loss/gain thru the use of advanced framing and enhanced insulation resulting in component U-factors significantly lower than those found in typical U.S. residences. A continuous air/moisture barrier in conjunction with a limited number of penetrations through the building envelope resulted in an air exchange rate of 0.6 air changes per hour at 50 Pa. The home incorporates a vast array of renewable and energy efficient technologies, a subset of which has been used to date including an air-to-air heat pump system with a dedicated dehumidification cycle; a ducted heat-recovery ventilation system; a whole house dehumidifier; a photovoltaic system; and a solar domestic hot water system. During its first year of operation (July 2013 through June 2014), the NZERTF produced an energy surplus of 1023 kWh. In February 2015, a second year of testing began to determine if the NZERTFs energy performance could be further improved by making changes based on observations during the first year. The changes consisted of installing a thermostat that incorporated control logic to minimize the use of auxiliary heat, using a whole house dehumidifier in lieu of the heat pumps dedicated dehumidification cycle, and reducing the ventilation rate to meet ASHRAE Standard 62.2. During the second year of operation the NZERTF produced an energy surplus of 2241 kWh. This paper will compare the performance for both years and quantify the energy impact of weather and operational changes.
, Payne, W.
, Kneifel, J.
, Ng, L.
, Dougherty, B.
, Ullah, T.
, Healy, W.
and Omar, F.
Small Changes Yield Large Results at NIST's Net-Zero Energy Residential Test Facility, Energy and Buildings, [online], https://doi.org/10.1115/1.4037815
(Accessed October 23, 2021)