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This paper explains typical knee wall construction and insulation in homes in Indiana and demonstrates the energy inefficiencies caused by such methods. Literature research gives examples of possible opportunities for changing the standard methods of knee wall construction and insulation. The methodology of the study is explained, as is energy intensity (EI) — the main evaluation tool used in this paper. EI allows a researcher to compare homes of different sizes in different locations. Overall, the study shows that homes whose knee walls have an air barrier backing use less energy than homes without knee walls. Additionally, as expected, homes with improperly constructed knee walls use the most energy. Finally, the paper contains recommendations about what methods might be used to change the standard practices involved in building and insulating knee walls. / Department of Urban Planning

L’isolation thermique par l’extérieure (ITE) constitue une solution technique intéressante pour améliorer les performances énergétiques du secteur du bâtiment. Cependant, l’ITE peut venir modifier l’équilibre hygrothermique de l’enveloppe et affecter sa durabilité, notamment au regard de l’humidité. Dans ce contexte, un premier travail a consisté à étudier en laboratoire le comportement hygrothermique de trois systèmes d’ITE rapportés sur une paroi en parpaing : un système ETICS (PSE sous enduit mis en œuvre par voie humide) et deux systèmes sous bardage (mis en œuvre par voie sèche), dont un incluant des matériaux biosourcés (laine de bois et ouate de cellulose). Des expériences en enceinte biclimatique, combinées à des simulations numériques des transferts couplés de chaleur et de masse, ont permis d’appréhender le comportement hygrothermique de ces parois rénovées à différents stades : lors de la pose des solutions d’ITE, en usage « normal » et dans des conditions conduisant à des risques de condensation. Les résultats du système ETICS montrent le rôle important de la colle et la difficulté à appréhender numériquement son comportement. Les résultats des systèmes sous bardage soulignent l’intérêt d’utiliser des matériaux biosourcés dans des conditions à risques, mais également la sensibilité des simulations numériques aux propriétés hydriques des matériaux hygroscopiques. Un second travail portant sur l’analyse in situ d’un système d’ITE sous bardage a souligné l’absence de risques majeurs liés à l’humidité durant les deux années étudiées. Par ailleurs, la comparaison simulation/expérience a mis en évidence le rôle important joué par la lame d’air ventilée. / External thermal insulation (ETI) is an interesting technical solution for improving the energy performance of the building sector. However, ETI may change the hygrothermal balance of the envelope and affect its durability, especially with regard to moisture. With this in mind, a first work consisted in studying the hygrothermal behavior of three systems of ETI set on a hollow concrete block wall in the laboratory: an ETICS system (wet process) and two systems under cladding (dry process), with one of them composed with bio-based materials (wood wool and cellulose wadding). Experiments in a bi-climatic enclosure, combined with numerical simulations of coupled heat and mass transfers, made it possible to apprehend the hygrothermal behavior of these renovated walls at different stages: during the installation of ETI solutions, in "normal" use and under conditions leading to risks of condensation. The results of the ETICS system show the important role of the glue and the difficulty to understand numerically its behavior. The results of the cladding systems underline the interest of using bio-based materials under hazardous conditions, but also the sensitivity of numerical simulations to the hydric properties of hygroscopic materials. A second study on the in situ analysis of a cladding ETI system highlighted the absence of major risks related to humidity during the two years studied. In addition, the simulation / experiment comparison highlighted the important role played by the ventilated air.

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This thesis examines existing rehabilitation and environmental guidelines to determine whether the guidelines are incorporating the necessary building science knowledge to ensure that insulation is performing as intended and thus promoting energy efficiency, cost effectiveness, and environmental sustainability. The results of analyzing the existing guidelines show that they do not require all that is necessary to promote energy efficiency and environmental sustainability. While several of the guidelines have started to incorporate the necessary building science perspective by requiring a whole house air leakage test, none of the guidelines examined specifically require the zonal pressure diagnostics test necessary to ensure that insulation is working to specification. The thesis also includes a comprehensive overview of environmental sustainability and rehabilitation. / Department of Urban Planning

The National Park Service has provided guidance to the public for years regarding weatherization measures for historic houses. Some of this guidance advised against installing wall insulation, citing the potential for moisture condensation resulting in structural damage. With the passage of the American Recovery and Reinvestment Act in 2009, a substantial investment was made in the 30 year old Weatherization Assistance Program, which provides federal funds for home weatherization. The program has used wall insulation with no reported problems and proven energy savings. Some State Historic Preservation Offices (who review federally funded actions) protested the use of wall insulation based on the NPS guidance, especially Preservation Brief #3. This thesis describes the fundamental differences between the preservation community’s approach to energy efficiency as compared to the weatherization community’s approach, and addresses some concerns of historic preservation officials regarding perceived potential damage of some weatherization measures, including wall insulation. / Introduction : HP and DOE programmatic agreement -- Energy efficiency guidance from the historic preservation community -- Guidance from the weatherization community -- Analysis of differences between preservation guidance and DOE guidance -- Recommendations. / Department of Architecture

Due to factors such as rising energy costs, diminishing resources, and climate change, the demand for high performance buildings is on the rise. As a result, several new building standards have emerged including the Passive House Standard, a rigorous energy-use standard based on a super-insulated and very tightly sealed building envelope. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference, annual heating energy is less than or equal to 15kWh/m2, and total annual source energy is less than or equal to 120 kWh/m2. A common complaint about passive houses is that they tend to overheat. Prior research using simulation suggests that the use of Phase Change Materials (PCMs), which store heat as they melt and release heat as the freeze, can reduce the number of overheated hours and improve thermal comfort. In this study, an actual passive house duplex in Southeast Portland was thoroughly instrumented to monitor various air and surface temperatures. One unit contains 130kg of PCM while the other unit contains no PCM to serve as an experimental control. The performance of the PCM was evaluated through analysis of observed data and through additional simulation using an EnergyPlus model validated with observed data. The study found that installation of the PCM had a positive effect on thermal comfort, reducing the estimated overheated hours from about 400 to 200.