Improving Air Distribution Systems (ADS) Performance
in Manufactured Homes (January 2003, 57 p.)
Virtually all manufactured housing units in the nation use
forced air systems for heating and cooling distribution. The
typical manufactured home air distribution system (ADS) wastes
a significant amount of energy through leakage of conditioned
air to the exterior. Reductions in this leakage have the potential
to reduce a home's annual energy bills by up to 10 percent;
making improving ADS performance the single most important
strategy for saving energy in manufactured housing.
This report documents visits by building scientists to 16
manufactured home plants to develop and demonstrate techniques
to build tighter duct systems and to train production personnel
in these techniques. The three key steps in the ADS construction
process that enabled individual plants to reach the target
leakage levels were: cutting accurate holes for registers
in floors and for duct connections by using templates, securely
and mechanically fastening ADS components rather than using
tape alone, and covering seams with proven durable sealants
such as mastic or appropriate tapes. The scientists adapted
standard duct leakage test protocols for use in the plant
environment in order to quantify performance improvements.
The training of plant staff and often the plant's Design Approval
Primary Inspection Agency (DAPIA) was designed to enable the
plant to maintain production of the improved ADS systems.
The lessons learned while working with the 16 plants was
widely distributed to the industry through articles in TECHNOLOGIES
and Modern Home, seminars and symposia at major industry trade
events, and posting on the MHRA web site. As a result of this
effort, the efficiency of the air distribution systems (ADS)
constructed at 16 manufactured home plants whose parent companies
produce over 85,000 homes per year was dramatically improved.
The average rate of duct leakage to the outside was reduced
to 3.7 percent from 13.6 percent observed in earlier studies
of homes produced at some of these plants.
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