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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]