Alternatives for Minimizing
Moisture Problems in Homes Located in Hot, Humid Climates: Interim
Report
An effort was undertaken to
examine manufactured homes in the Gulf Coast area, gather
information on condensation-related moisture problems in those
homes, and determine the contributing factors to those problems.
Building scientists gathered data from 70 homes with and without
moisture problems. A thorough literature review, examination of the
data, and neural network analysis of the data were used to evaluate
and prioritize the significance of twelve potential contributors to
moisture problems, in terms of their impact in causing such
problems. This document reports on the findings of this research
effort.
Significantly, the results of
the neural network analysis indicated that 62% of the problems could
be explained by a number of the identified contributors. These
results, in combination with other data analysis and the literature
review helped to prioritize the full list of contributors in terms
of their impact on moisture problems and to and classify them into
three groups. In order of decreasing significance, these were found
to be:
- Pressure imbalances,
including those caused by imbalances in the distribution of
conditioned air, duct leakage, and shell leakage.
- Vapor retarders and air
barriers as a complete system, including the walls (wall air
barriers and vapor retarders), floor (bottom board and ground
cover) and ceiling (ceiling air barrier and vapor retarder).
- Occupant comfort, which
is affected by a combination of indoor temperature and humidity
levels.
It was also concluded that
statistical analysis and modeling can play a supporting role in
identifying major causes of condensation-related moisture problems
but cannot fully explain the nature and source of moisture problems.
As a result of this prioritization, further work is recommended that
will focus on the three moisture problem contributor areas
identified above, with an emphasis on the first two: pressure
imbalances and vapor retarders/air barriers. This work will require
testing and evaluation of unoccupied homes and building subsystems
under controlled conditions. It will produce specific guidelines for
the minimization and remediation of moisture problems for
manufacturers, installers, service personnel, and homeowners of
manufactured homes in the hot, humid climate of the Gulf Coast
region.
Source:
Adobe Acrobat
(*.pdf, 646KB)
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