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This paper investigated the effect of individual differences and the type of heating system on the perceived thermal comfort condition, neutral temperature, and thermal sensitivity in cold outdoor air conditions. Three types of individual factors, such as gender, temperament, and thermal past experience, were studied and compared in this paper. According to the results, temperament and thermal past experience directly influenced the occupants' thermal preference and indirectly influenced the thermal sensation by affecting their clothing level. However, the effect size of such variations was negligible. The type of heating system had the most significant impact on the neutral temperature, with a mean difference of 2.8°C. Individual factors did not have a direct impact on the neutral temperature. However, thermal sensitivity was influenced by an individual's temperament. Occupants with a cold temperament were more sensitive to the variation in the running mean outdoor temperature (Trm) than those with a warm temperament. When the results were compared with the predictions by the adaptive thermal heat balance (ATHB) and the predicted mean vote (PMV) models, it indicated that if the control condition over the heating system became limited, there would be no (i.e., very low) behavioral, physiological, and psychological adaptation. However, by creating an opportunity to control the heating system, thermal adaptation could be reached at a lower temperature under cold outdoor air conditions. Comfort is subjective and influenced by environmental factors and personal differences. For example, individuals might feel different and hotter or cooler at the same ambient temperatures. In addition, individuals could adapt to the environment and afford their comfort with lower costs than the heat predicted mean vote (PMV) and the cooling load calculation showed. The results of this paper could help to understand why people have different thermal perceptions under the same environment and might lead to the identification of the important nonenvironmental factors that impact the perceived feeling of health, well-being, and educational performance. Therefore, influencing decision-making during the design and maintenance of educational buildings. The results indicated that individual differences influenced the level of clothing and occupant preference. These differences influenced the variation in occupants' thermal sensitivity to indoor and outdoor air temperatures. However, they had a negligible influence on the neutral temperature. The heating systems had the most impact on the neutral temperature. The opportunity to control heating systems could lead to the thermal comfort condition being achieved at a lower temperature in cold outdoor air temperatures, which could reduce energy consumption. [ABSTRACT FROM AUTHOR]

This paper evaluated the cement-based materials incorporated with novel solid–gel phase change materials (PCMs) for improving the energy efficiency of building envelopes. This novel PCM is form-stable, which will not leak as solid–liquid PCMs do and not need encapsulation, and it features high energy-storage capacity. Experimental results showed that the thermal properties of cement-based materials were improved as the increase of PCM content. A 30% replacement of sand by volume with PCM can increase the latent heat of the mixture from around 0 to 7 J/g and decrease the thermal conductivity of PCM mortar based on the generalized self-consistent (GSC) model by about 20%. However, the workability and mechanical properties were compromised. The simulation results indicated that 30% PCM-incorporated walls can contribute to 5% energy saving for cooling in a whole year and 12% reduction in peak cooling load compared with the reference without PCM. The proposed PCM composite offers a promising avenue to achieve energy-efficient building envelopes. [ABSTRACT FROM AUTHOR]

This paper assesses the dynamic thermal inertia performance of unfired clay bricks with dry-grass fiber additives. The used raw material was retrieved from Ifrane in Morocco. The used clay was illite with a 59.60% silicon proportion. Multiple percentages (0%, 1%, 7%, and 15%) were analyzed in this study. The dynamic thermal inertia simulation was carried out in TRNSYS software to investigate the specimens' time lag, decrement factor, and heating and cooling loads. For this purpose, a reference house with three different wall thicknesses (0.20, 0.25, and 0.30 m) was evaluated. Collected findings reflected great time lag improvements. With the incorporation of 15% additive, 13.11 h was recorded. This reflected a thermal gain of 49.12% with the use of 0.30-m-thick walls. Decrement factor analysis also recorded interesting improvements. Thermal cooling and heating loads also recorded prominent energy savings of 95% and 60%, respectively. Finally, adopting thicker building walls recorded great thermal gains in the range of 60%. [ABSTRACT FROM AUTHOR]

Cooling buildings represent a major environmental issue, especially during summers. Although thermal insulation can decrease cooling loads, the presence of thermal bridges, infiltrations, windows, and other openings pose a continuous challenge. In the Middle East and North Africa (MENA) region, for instance, most windows are made of aluminum, a thermal conductor. This paper uses two methods to evaluate the alternative solution of enveloping buildings, including windows, with a secondary layer. The first method involved small-scale models; two test rooms were built, with one (the reference room) being based on regular municipal thermal guidelines and the other (the enveloped room) including an extra, secondary surrounding layer. The second test staged a similar scenario via software simulation. Both sets of results showed a significant reduction in electricity consumption in the enveloped room, which became more notable as the weather grew hotter. At the high end of the temperature scale, the power consumption of the enveloped room was 47%–54% lower than that of the reference room. However, such a secondary building envelope would increase the width of the wall structure and present the downside of adding to construction costs. While adopting this system in Dubai may save the city an estimated 16.6% in electrical energy, based on current prices, a house would likely need between 10 and 15 years to recuperate the associated capital investment. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of experimental investigations on steel composite beams with simple connections at elevated temperatures. In the United States, three different types of simple connections are most commonly used in building construction with steel composite beams: (1) double-angle connections; (2) single-angle connections; and (3) shear-tab connections. A testing program was conducted to examine the structural behavior of all three of these connections at elevated temperatures. Each specimen consisted of a steel composite beam attached to a loading frame with simple connections. The specimens were subjected to controlled heating and cooling curves while the loading frames were fire protected and designed to remain in the elastic range. The shear-tab connections showed the largest connection rotation, but they fractured during the cooling phase of the tests. The prying of the angles in the double-angle and single-angle connection during the tests provided ductility to prevent fracture during the cooling phase of the experiments. The double-angle connections demonstrated the least connection rotation and excellent performance during the tests. [ABSTRACT FROM AUTHOR]

This study analyzes simulated secondary (site) energy consumption before and after applying a series of building envelope retrofits to inform a prioritized list of retrofit options tailored to one of four single-family dwelling styles in Toronto, Ontario, Canada. Four archetype homes were developed to represent Toronto's existing urban housing stock: (1) 2-story century home; (2) wartime bungalow; (3) 1970s Ontario Building Code 2-story home; and a (4) 2-story modern house. Base case geometry and inputs were developed from a variety of sources, including a Canadian national database and modeled using the HOT2000 software package. The prioritized retrofit strategy worked toward achieving a target secondary energy intensity of and included increasing insulation levels in the main walls, foundation walls, slab, and ceiling, replacing windows and doors, and air sealing to various degrees. Results showed the retrofit strategies affected each archetype differently, leading to the conclusion that certain retrofits would have a much greater impact on one typology compared with another. Archetype specific recommendations were made that showed a generic approach to retrofitting an urban housing stock might not be the optimal solution. [ABSTRACT FROM AUTHOR]

Buildings have time-varying interactions with the local climate condition for the heating or cooling systems; changes of the surrounding climate condition affect building energy consumption. Based on the thermal envelope approach, which considers the heat gain by conduction and radiation through the wall and fenestration, the cooling load simulation study was conducted to see the impact of climate change on the cooling load of public residential buildings in Singapore and propose mitigation methods to bring the predicted increase of the cooling load in the future back to the current level. From the simulation results, climate change is predicted to increase the cooling load of current public residential models for 11.8-55.8% through three different time frames. Based on the parametric study of mitigation methods proposed, changing the material of the wall, material of the glass, and the surface properties show a smaller increase in the predicted cooling load compared with other methods because of the low window to wall ratio. A combination of three methods shows that the increase of the predicted cooling load in Period 3 can be brought back to the current level. [ABSTRACT FROM AUTHOR]

In this study, a widely used software package, Trace 700 was used to simulate the energy consumption of the heating and cooling loads of two residential homes and compare them with their experimental values. One home is classified as a zero energy home (ZEH) and employs advanced construction features, which is designed to consume significantly less energy than a normal home. The baseline home is of the exact same dimensions and floor plan as the ZEH, but uses more traditional construction practices. Trace was used to model both homes during periods where both cooling and heating were used, respectively, for an available period of two weeks in 2005. Actual weather data from the vicinity were obtained during the monitoring phase and were introduced into Trace as input data to create a more accurate representation of the conditions. The difference between the simulated predictions and the actual experiments showed an average difference of 2.25 and 6.29% for the baseline house for cooling electric energy and heating energy, respectively, while that difference was 10.67% in cooling for the ZEH. No estimate is presented to the difference in the heating mode for the ZEH due to a plumbing problem. The data showed the ZEH reduced the cooling load by about 76% experimentally and 75% by simulation. The simulation comparison between the baseline and ZEH indicate a reduction of the heating load of about 12%. [ABSTRACT FROM AUTHOR]

This work investigated a trigeneration system for the building sector. Biomass is the utilized energy source which feeds an organic Rankine cycle for electricity production. Heating is extracted from the power cycle, especially with the proper heat exchanger after the turbine. A vapor compression heat pump is used for cooling production, and it is fed by work power from the turbine shaft. The total configuration was examined parametrically by investigating different superheating cases, pressure levels, and ambient temperatures. The analysis was energetic and financial for the climate conditions of Athens, Greece. For the case with a nominal cooling load of 10 kW, the system's yearly energy and exergy efficiencies were 48.68% and 24.86% respectively. The payback period was 5.02 years, the net present value was €118,000, and the internal rate of return was 21.57%. The yearly electrical, heating, and cooling production were 99.39, 91.17, and 22.67 MWh respectively, whereas the biomass energy input was 438 MWh on a yearly basis. [ABSTRACT FROM AUTHOR]