References
- Climate Prediction Center Internet Team, National Oceanic and Atmospheric Administration (NOAA), Degree days explanation, (2008); available at http://www.cpc.noaa.gov/products/analysis_monitoring/cdus/degree_days/ddayexp.shtml.
- Department of Housing and Urban Development, Heating and cooling degree data by zip code, (2008); available at http://www.huduser.org/portal/resources/UtilityModel/hdd.html.
- Energy Star, a joint program of the U.S. Department of Energy and Environmental Protection Agency, Recommended levels of insulation, (2009); available at http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table.
- R. L. Martin, ColoradoENERGY.org, R-value table, Insulation values for selected materials (2007); available at http://www.coloradoenergy.org/procorner/stuff/r-values.htm.
- J. Walker, Fundamentals of Physics, eighth ed., Wiley, NJ, 2008.