C046 -- Empirical Validation of Whole Building Energy Simulation Program under Free-Floating Conditions (C046)

This paper presents one of the ongoing EnergyPlus validation efforts using a low-load residential single family home: the Net-Zero Energy Residential Test Facility (NZERTF) located on the campus of NIST in Gaithersburg, MD, USA. This paper presents the preliminary results of a free-floating test during the heating season when the HVAC system stayed OFF for one week. The EnergyPlus model of the NZERTF was first created based on as-built drawings and then refined to properly reflect the test conditions. Highlights of this work include the use of advanced interzonal and infiltration airflow calculations using CONTAM airflow program and a comparison of two ground heat transfer models to improve the EnergyPlus model.