Achieving Airtight Ducts in Manufactured Housing

Abstract

This Florida Solar Energy Center (FSEC) study, conducted under the auspices of the U.S. Department of Energy's Building America Industrialized Housing Partnership (BAIHP), compares mastic sealed duct systems to tape sealed systems by showing measured total duct leakage (CFM25TOTAL and QnTOTAL) and/or measured leakage to the outside (CFM25OUT and QnOUT) in 190 manufactured home floors or home sections. All manufacturers were considering or actively working toward achieving duct leakage below 3% of the conditioned floor area (QnOUT=0.03), consistent with Energy Star Manufactured Homes criteria. Previous field tests suggest that CFM25OUT accounts for about half of CFM25TOTAL. These data show that achieving CFM25TOTAL=6% during production was generally correlated with achieving CFM25OUT=3% in mastic sealed systems, but less reliably with taped systems. Cost for achieving duct tightness goals range from $4 to $8 including duct testing on the assembly line