Data & Analysis Sources

Following is a high-level summary of the sources of information and data used in the Home Energy Saver calculation methodology, organized by major energy end use or subject.  These apply to the existing single-family housing modeling system; new methods and sources are being added for multi-family.  More specific sources are documented in context within the pages of this Wiki, and a full listing of primary sources is here.

Analysis Techniques

  • HVAC calculations - DOE 2.1E.1245 hourly simulation model (Birdsall et al. 1990)
  • Disaggregation of the U.S. into 19 climate zones for top-level benchmarking: developed by LBNL in a project for the Gas Research Institute (Ritschard et al. 1992) and extended by Huang (Huang et al. 1999) and Apte (2004).
  • Domestic hot water calculations – DOE appliance standards methodology for water draw and DOE Energy Factor methodology for water-heating energy (a new methodology for multi-family is being completed at this time and will be documented separately).  Details here.
  • Appliance unit-energy consumption default values are determined by user-entered vintage  – Sales-weighted efficiencies (by vintage) per GAMA, ARI, etc. (through 2010 in most cases) or by formulas derived by Wenzel et al. (1997)
  • Lighting - computed based on lamp county, type, wattage, and utilization, by fixture
  • Duct losses – ASHRAE Standard 152.
  • Upgrade levels - "Floor" is defined as lower-end of Energy Star levels; higher levels also provided.

Defaults (virtually all can be over-ridden by users)


  • Benchmarked energy use – RECS micro data (2005) (2009 pending)
  • Emissions factors – USEPA - EGRID (2009)
  • Energy Prices – DOE/EIA – State Energy Data System (SEDS), Electric Power Monthly, Natural Gas Monthly.
  • Source energy conversions – Deru and Torcellini (NREL) (2007)
  • Weather data – TMY1 and TMY2 (converting soon to TMY3)
  • Air leakage – LBNL air leakage database (update anticipated Q2 2012)