A rule-based expert system applied to moisture durability of building envelopes

Abstract

The moisture durability of an envelope component such as a wall or roof is difficult to predict. Moisture durability depends on all the construction materials used, as well as the climate, orientation, air tightness, and indoor conditions. Modern building codes require more insulation and tighter construction but provide little guidance about how to ensure these energy-efficient assemblies remain moisture durable. Furthermore, as new products and materials are introduced, builders are increasingly uncertain about the long-term durability of their building envelope designs. Oak Ridge National Laboratory and the US Department of Energy's Building America Program are applying a rule-based expert system methodology in a web tool to help designers determine whether a given wall design is likely to be moisture durable and provide expert guidance on moisture risk management specific to a wall design and climate. The expert system is populated with knowledge from both expert judgment and probabilistic hygrothermal simulation results.

Risk Assessment Framework to Avoid Serial Failure for New Technical Solutions Applied to the Construction of a CLT Structure Resilient to Climate

“…According to [15], the purpose of probabilistic studies on mold growth was to emphasize uncertainties, evaluate performance with the aim of differentiating between designs, and evaluate uncertainties and identify important ones. From the probabilistic methods, there was also an effort to compile the research results to create accessible models based on advanced simulation tools, such as within the EU projects RIBuild [16] and Tallfacades [17], to handle internal insulation of historical buildings and envelopes in wooden structures, respectively, as well as the wall assessment system BSA [18]. Within predefined boundaries and preset assumptions, the user can benefit from probabilistic assessment based on large sets of simulations when evaluating performance of building components; however, when introducing new technical solutions, these models are usually not applicable as they are based on preset boundaries.…”

Opaque Envelopes: Pathway to Building Energy Efficiency and Demand Flexibility: Key to a Low-Carbon, Sustainable Future

“…Simplified high-level guidance tools that leverage envelope models-such as the Airtightness Savings Calculator [24] or Building Science Advisor [31]-can be used for customer acquisition or education purposes to demonstrate the value, in general, of high-performance opaque envelope materials and assemblies to building owners, suppliers, and designers. However, these tools use the DOE prototype building models, which, as mentioned, might lack the building geometry and characteristics required to accurately inform building-or project-specific decisions.…”

Vapor barrier membranes based on polylactic acid and cellulose microfibers for the building envelope application

“…In a cold climate like Canada, the water vapor concentration inside of buildings is higher than in the exterior environment, leading to moisture ow through the building wall [4]. The diffusion and accumulation of moisture in building envelopes cause mold growth, structural damage, and deterioration of building materials [5]. The migration of moisture through walls, roof assembly, oors, and ceilings can be controlled by the installation of a vapor barrier/retarder membranes on the warm side of buildings, thereby preventing interstitial moisture condensation [6].…”