Hvac Improvements In Manufactured Housing Crawlspace-Assisted Heat Pumps

Factory installation of crawlspace-assisted air-source heat pumps in manufactured homes avoids the need for an HVAC contractor to install the equipment on-site. The heat pump\u27s outside coil is located in the back of the indoor unit. Air is drawn from a vented crawlspace over the coil and exhausted above the roof. The U.S. Department of Energy Building America Program Industrialized Housing Partnership has monitored these systems in energy-efficient manufactured homes in the Pacific Northwest. The researchers conducted HVAC flip-flop tests and presented results that compare the in-situ heat pump performance with electric resistance heating. They also evaluated the energy impacts of the defrost cycle and use of vented crawlspace air. This paper covers equipment installation, HVAC market distribution system barriers, and anecdotal maintenance and operation observations, along with recommendations. © 2007 ASHRAE