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Integrated Hygrothermal Performance of Building Envelopes and Systems in Hot and Humid Climates
Abstract
In hot and humid climates the interior and exterior
environmental loads that building envelopes must
respond to are larger than many other climatic
conditions. Moisture-originated failures in low-rise
residential buildings have put a significant pressure to
change construction codes in North America.
Solutions to moisture induced problems may be
difficult when several interacting mechanisms of
moisture transport are present. A new approach to
building envelope durability assessment has been
introduced in North America; a moisture engineering
approach. This requires system information about the
wall systems as constructed along with aging
characteristics coupled with advanced modeling that
0 term allow the designer to predict the Iong-term performances of building envelope systems. This
permits the comparison and ranking of individual
building envelope systems with respect to total
hygrothermal performance.
Critical information can be obtained by investigating
the one to one relationships of a building envelope to
interior and exterior environments, however, the total
behavior of the actual whole building is not
accounted for. This paper goes one step further, by
incorporating the individual hygrothermal
performances of all walls, roof, floor and mechanical
systems. The direct and indirect coupling of the
building envelope and indoor environment with
HVAC system are included in the analysis. The full
house hygrothermal performance of an aerated
concrete wall system are examined for a hot and
humid climate. The hour by hour drying potential of
each system was then numerically analyzed using
weather conditions of Miami (hot and humid
climate). The results clearly demonstrate the limited
drying potential for the wall system in that climate.
Furthermore, the selected exterior thermal insulation
strategies and interior vapor control strategies in this
study clearly show the critical behavior of the full
house with respect to drying initial construction
moisture. The results show the importance of the
total hygrothermal behavior of the whole house to the
coupling between the various envelope parts, interior
and exterior environments and HVAC system. From
these results moisture control strategies are identified
for the whole house hygrothermal performance.
Citation
Karagiozis, A. N.; Desjarlais, A.; Salonvaara, M. (2000). Integrated Hygrothermal Performance of Building Envelopes and Systems in Hot and Humid Climates. Energy Systems Laboratory (http://esl.tamu.edu); Texas A&M University (http://www.tamu.edu). Available electronically from https : / /hdl .handle .net /1969 .1 /6791.