Publications

Total System Performance Ratio (TSPR) is a metric for evaluating overall system efficiency instead of individual component efficiency, a solution that could also eventually facilitate the transition to a 100% performance-based code structure. TSPR is a ratio that compares the annual heating and cooling load of a building to the annual energy consumed by the building's HVAC system. This technical documentation provides background on the TSPR and support for the mechanical performance factors that are developed each 90.1 edition cycle to be used in the calculation. The current factors are developed for the 2022 edition of 90.1 in combination with addendum AG.

The most recent edition, the 2021 IECC, was published on January 29, 2021, triggering the DOE review and determination process2. DOE and Pacific Northwest National Laboratory (PNNL) conducted a technical analysis to determine energy savings for the 2021 IECC residential provisions relative to the previous edition, the 2018 IECC (ICC 2017). This report documents the methodology used to conduct the analysis and summarizes the results.

The most recent edition, the 2018 IECC, was published in August 2017, triggering the DOE review and determination process. In response, DOE and Pacific Northwest National Laboratory (PNNL) conducted a preliminary analysis to determine energy savings for the 2018 IECC residential provisions relative to the previous edition--the 2015 IECC. This report documents the methodology used to conduct the analysis and summarizes the results and findings.

This report explains the methodology used to develop version 4.6.5 of the REScheck software in order to support compliance determination for IECC editions 2009, 2012, 2015, and 2018.