The Northwest Energy Efficiency Alliance (NEEA) contracted with Ecotope, Inc. and Cascade Engineering Services, Inc. to conduct a laboratory assessment of the Stiebel-Eltron Accelera 220 E heat pump water heater (HPWH) for northern climate installations. Cascade Engineering evaluated the Accelera 220 E using a testing plan developed by Ecotope to assess HPWH performance. The report written by Nick Kvaltine and Ben Larson suggests that the Stiebel-Eltron Accelera 220 E is a highly-efficient water heater. Read the full report here: Laboratory Assessment of Stiebel Eltron Accelera 220 E HPWH