This study presents a summary of lab and field research conducted by the Northwest Energy Efficiency Alliance (NEEA) from 2013 through 2016 on heat pump clothes dryers for the North American Market. NEEA developed a modified lab test protocol that adds four test cycles to the U.S. Department of Energy’s dryer test protocol. The additional cycles use real clothing in a variety of load sizes and cycle settings. The resulting metric has proven to be a better indicator of actual field performance.
Lab testing of heat pump equipped clothes dryers are compared to three field studies of clothes washer and dryer pairs in 27 homes. The outcome of these lab and field tests are: 1) a multi-tiered dryer efficiency specification that is the basis of utility energy savings estimates, 2) a qualified products list used to promote high efficiency dryers sold in the Pacific Northwest, and 3) recommendations on how future test protocols can be improved.