Evaluation of the U.S. Test Procedure for Residential Clothes Dryers

The Northwest Energy Efficiency Alliance (NEEA) contracted with Kannah Consulting to evaluate whether the U.S. Department of Energy’s current clothes dryer test procedure (Appendix D2 to 10 CFR Part 430) accurately predicts dryer energy use under real-world operating conditions. The study assessed 12 top-selling electric clothes dryers representing three efficiency groups: non-qualified, ENERGY STAR® qualified, and heat pump models. Each dryer was tested using the Appendix D2 procedure and under additional load conditions informed by NEEA’s 2023 laundry field study to compare laboratory results with common household usage patterns. 

Report findings provide insight into how clothes dryer energy performance varies across different load sizes and operating conditions, including the use of Eco mode settings. The findings also identify opportunities to better align laboratory test results with common household usage patterns. Because the Appendix D2 test procedure is used to establish federal efficiency standards, determine ENERGY STAR qualification levels and support utility efficiency programs, these results may help inform future discussions about dryer performance testing. NEEA will review the findings and consider next steps.