The Northwest Energy Efficiency Alliance (NEEA) hired Ecotope, Inc., supported by Research Into Action, Inc., and Stellar Processes to evaluate the Northwest Ductless Heat Pump (DHP) Pilot Project (pilot project). The pilot project ran from October 2008 through December 2009. A total of 3,899 installations were included in the pilot project. The DHP Impact and Process Evaluation (DHP evaluation) includes a tiered analysis of five components of technical performance and market acceptance: market progress evaluation, laboratory testing, field monitoring, billing analysis, and cost-effectiveness.