Electric utilities in the Pacific Northwest have spent over $100 million to support energy efficiency improvements in the HUD-code manufactured housing industry in the Pacific Northwest over the past several years. Over 65,000 manufactured housing units have been built since 1991 that exceed the new HUD standards for both thermal performance and mechanical ventilation that became effective in October, 1994. All of these units included mechanical ventilation systems that were designed to meet or exceed the requirements of ASHRAE Standard 62-1989. This paper addresses the ventilation solutions that were developed and compares the comfort and energy considerations of the various strategies that have evolved in the Pacific Northwest and nationally. The use and location of a variety of outside air inlets will be addressed, as will the acceptance by the occupants of the ventilation strategy.