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The quest for a sustainable built environment brought dramatic changes to architectural design because of the integrated design process. The integrated design process is the modern way to realize “performance architecture,” that is, design with a view to field performance. Integrated design process permits merging of concepts from passive-house designs, solar engineering, and an integration of the building enclosure with mechanical services. In part 1 of this series, the emergence of many new multi-functional materials was discussed. Yet, current innovation is guided by lessons from history. Thermal mass in heavy masonry buildings allowed periodic heating. The authors postulate integration of a hydronic heating system with the walls and the use of smart temperature control of the heating system to modify and optimize the thermal mass contribution. To use the mass of a building, one must accept transient temperature conditions where the indoor temperature varies but is confined by comfort requirements for both summer and winter conditions. On the other side, resiliency requirements dictate that in the absence of electricity the air temperature does not fall below about 12°C over a period of several hours. This requirement implies that summer cooling will likely be separated from the heating systems and that operation of a low-energy building is heavily dependent on the design of smart control systems. Analysis of control systems provided in this article for earth-to-air heat exchangers and cooling of houses with lightweight walls lead us to the requirements of separation between heating and ventilation and needs for different sources of fresh air. Finally, a new concept emerges.

A study of the factors which affect the thermal conductivity of αFe and its solutions is described. The results of these experiments define the phonon and electronic components of the thermal conductivity of pure αFe fairly well between 90 and 400 K. Also, the phonon conductivity can be analyzed to identify the strengths of electron-phonon and phonon-phonon scattering, and the latter resistance is in good agreement with theoretical estimates. The scattering of phonons by electrons is intermediate between the small values for noble metals and the strong scattering found in Nb and Ta. An experimental estimate of the electron-phonon mass enhancement factor, 0.4, is derived from the results. Finally, reexamination of the data for ten solid solution alloys suggests that both phonon-scattering mechanisms are influenced by the alloying elements.

The previous part of this article starts 100 years ago, at the time of the humble beginnings of building science, and brings us to the current stage of the net zero energy buildings (NZEB). We see how, over the years, knowledge from the observed failures of buildings has accumulated to become the basis for current building science. The strong interactions between energy efficiency, moisture management, and indoor environment and the need for their simultaneous analysis led to the concept of environmental assessment. More than 40 years of experience with passive houses (the first 10 were built in Canada in 1977) in process that would collect those developments into the mainstream of NZEB technology permits extrapolation to the future. As the first priority, we see a need for a fundamental change in the approach to NZEB—instead of improving the separate pieces of the puzzle before assembling them, we need first to establish the conceptual design of the whole system. Only after determination of the basic requirements for each subsystem and each assembly may materials that would fulfill the specific requirements of this assembly be selected. In this design process, the actual climate and socio-economic conditions (including construction cost) vary, so we must deal with a set of design principles rather than a description of a specific construction technology. A guiding set of considerations is presented below to establish a system of environmental quality management (EQM).

The discussion in this article starts in the 1920s, that is, at the time of the humble beginnings of building science and brings us to 2020s with the development of net-zero energy buildings. The knowledge accumulated by explaining observed failures in the practice of construction slowly formed a basis for moving toward a predictive capability and to an integration of modeling and testing. Furthermore, we have learned that interactions between energy efficiency, indoor environmental quality, and moisture management are so critical that the three issues must be considered simultaneously. Effectively, a change in the low energy is needed to ensure durability of materials and cost considerations for these buildings. At this stage, one could observe a clear change in the mind-set of the scientific community. Forty years after construction of the first 10 passive homes, we made a shocking observation—an adequate technology has been developed, but our lack of vision prevents effective use of this technology. Again, we need to modify our vision and change the design paradigm to balance comfort, building durability, and cost-effectiveness. If the quest for sustainable buildings is our ultimate objective, then we should learn more from the surrounding nature; termites appear to master the art of hygrothermal control better than humans because they can optimize transient conditions to maintain a stable interior comfort zone. Thus, in the article to follow a new compact building envelope design package is proposed, applicable to different climates with specific modifications of critical hygrothermal material properties. This approach is called the Environmental Quality Management. This will be the second step for a building science (physics) needed to become a leading force in the transition to sustainable built environments.

This is an overview of a Key Note lecture; the quote for this lecture is from T.S. Eliot: “We must not cease from exploration and at the end of all our exploring will be to arrive, where we began, and, to know the place for the first time”. This quote highlights that the process of scientific development goes in circles, yet each of them goes above the previous circle, building up the ladder of knowledge. Closing one circle and opening the next may be either be a quiet, unnoticeable event or a roaring loud, scientific revolution. Building science (physics) was started about 100 years ago, but only now are we closing its second circle. Perhaps, because of building physics’ role in the fourth industrial revolution, this discipline itself is undergoing a scientific revolution The first industrial revolution was based on steam generated by burning coal, the second was based on petroleum, and the third on electricity and concentrated electricity production. The current one, i.e., the fourth, is based on distributed energy sources combined with information technology.

Experimental determination of the phonon and electron components of the thermal conductivity of bcc iron

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