Impact of newer climate data for technical analysis of residential building energy use in the United States

In this study, we describe an analysis indicating the relative importance of newer hourly weather files for simulation analysis of the energy use of residential buildings in North America. Results show that older TMY3 (ending 2005) data compared with newer TMY2021 (2007-2021) data are less appropriate for the best prediction of low-energy buildings. The balance of heating and cooling is significantly altered in the more recent TMY files with potential impacts on best performing energy efficiency measures. With 64 high profile North American locations evaluated, we found heating to be approximately 11% lower with the newer data, while cooling was increased by a similar amount percentage wise. However, the dominance of space heating in North America made decreases to heating considerably larger in an absolute sense so that overall space conditioning energy fell. Small changes in annual temperature can have large impacts. For all electric homes with air source heat pumps, we found that a change of 1 degrees C to outdoor temperature can produce about a 19 % change in space conditioning energy. The newer data also shows increased average solar electric output from simulated rooftop photovoltaic systems, likely due to more sophisticated solar irradiance data. Water heating was about 3 % lower given rising groundwater temperatures and inlet water temperatures to water heating systems. Results also showed that the newer data tended to increase savings from comprehensive building efficiency efforts in all electric buildings. This largely takes place because higher temperatures in winter allow air source heat pumps to meet heating needs more efficiently. Generally, the direction of these influences ease pathways to reach zero energy buildings in North America.