The Northwest Energy Efficiency Alliance (NEEA) contracted with Ecotope, Inc. and Cascade Engineering Services Inc., to conduct a laboratory assessment of the AO Smith Voltex hybrid heat pump water heater (HPWH) for northern climate installations. Using a testing plan developed by Ecotope to assess heat pump water heater performance, Cascade Engineering Services evaluated the AO Smith Voltex. The project examined both tank model sizes: 60 gallons and 80 gallons.