Energy consumption for cooling purposes has increased significantly in recent years, mainly due to population growth, urbanization, and climate change consequences. The situation can be mitigated by passive climate solutions to reduce energy consumption in buildings. This study investigated the effectiveness of the green roof concept in reducing energy demand for cooling in different climatic regions. The impact of several types of green roofing of varying thermal conductivity and soil depth on energy consumption for cooling school buildings in Egypt was examined. In a co-simulation approach, the efficiency of the proposed green roof types was evaluated using the Design-Builder software, and a cost analysis was performed for the best options. The results showed that the proposed green roof types saved between 31.61 and 39.74% of energy, on average. A green roof featuring a roof soil depth of 0.1 m and 0.9 W/m-K thermal conductivity exhibited higher efficiency in reducing energy than the other options tested. The decrease in air temperature due to green roofs in hot arid areas, which exceeded an average of 4 °C, was greater than that in other regions that were not as hot. In conclusion, green roofs were shown to be efficient in reducing energy consumption as compared with traditional roofs, especially in hot arid climates.
Building insulation based on nanomaterials is considered one of the most effective means of reducing energy consumption in the hot desert climate. The application of an energy-efficient insulation system can significantly decrease the energy consumed via a building’s air-conditioning system during the summer. Hence, building insulation has become an interesting research topic, especially with regards to the use of insulation based on nanomaterials due to their low U-values. In the present study, the use of nano vacuum insulation panels (VIPs) or polystyrene foam in the walls enabled a significant reduction in the annual energy consumption, a savings of 23% compared to the uninsulated wall in a study in New Aswan City. The application of nanogel glazing to the windows (two layers of clear glass filled with the nanogel) achieved approximately 11% savings in annual energy. This savings, twice that obtained by using double-glazed windows, could be due to the low U-value of nanogel compared to the U-values of argon or air. The embedded nanogel layer between two layers of argon and two layers of single clear glass showed a significant reduction in annual energy consumption, saving 26% compared to the use of a single layer of glass. Moreover, the integration between this window and embedded walls with 50 mm of polystyrene foam exhibited a significant improvement of energy efficiency by 47.6% while presenting the lowest value of simple payback period (SPP). This research provides a way for buildings to be insulated to make them more energy efficient as well as attractive from the economic standpoint.
The density of building blocks and insufficient greenery in cities tend to contribute dramatically not only to increased heat stress in the built environment but also to higher energy demand for cooling. Urban planners should, therefore, be conscious of their responsibility to reduce energy usage of buildings along with improving outdoor thermal efficiency. This study examines the impact of numerous proposed urban geometry cases on the thermal efficiency of outer spaces as well as the energy consumption of adjacent buildings under various climate change scenarios as representative concentration pathways (RCP) 4.5 and 8.5 climate projections for New Aswan city in 2035. The investigation was performed at one of the most underutilized outdoor spaces on the new campus of Aswan University in New Aswan city. The potential reduction of heat stress was investigated so as to improve the thermal comfort of the investigated outdoor spaces, as well as energy savings based on the proposed strategies. Accordingly, the most appropriate scenario to be adopted to cope with the inevitable climate change was identified. The proposed scenarios were divided into four categories of parameters. In the first category, shelters partially (25–50% and 75%) covering the streets were used. The second category proposed dividing the space parallel or perpendicular to the existing buildings. The third category was a hybrid scenario of the first and second categories. In the fourth category, a green cover of grass was added. A coupling evaluation was applied utilizing ENVI-met v4.2 and Design-Builder v4.5 to measure and improve the thermal efficiency of the outdoor space and reduce the cooling energy. The results demonstrated that it is better to cover outdoor spaces with 50% of the overall area than transform outdoor spaces into canyons.
In hot, arid regions, outdoor spaces suffer from intense heat. This study explores how vegetation can improve outdoor thermal performance for pedestrians in low-density residential areas. Specifically, it seeks to identify the best combination of grass and trees for optimal comfort. Four scenarios were simulated using ENVI-met software, varying the proportions of grass and three tree types: 50% grass, 50% grass with 25% trees, 50% grass with 50% trees, and 50% grass with 75% trees. A reference scenario with no vegetation was also investigated. The simulated outputs encompassed air temperature (Ta), mean radiant temperature (Tmrt), relative humidity (RH), and physiologically equivalent temperature (PET). The findings show that scenarios with a higher percentage of trees exhibited the best reduction in air temperature, ranging from 0.2 k to 0.92 k. Additionally, the inclusion of trees and grass in the scenarios resulted in a substantial improvement in thermal performance, with an average reduction of 7.5 degrees in PET. Among the evaluated scenarios, the one comprising 75% trees and 50% grass exhibits the most noteworthy enhancement. This study underscores the significance of strategically positioning vegetation to coincide with prevailing wind patterns, thereby enhancing convective cooling mechanisms and improving overall thermal comfort levels. These insights offer valuable implications for urban planning and the development of sustainable design strategies.
Excessive urban construction is primarily driven by uncontrolled population growth, which has serious consequences for the environment, energy, cost, and human life in general when building materials are massively used. In terms of energy and economic efficiency, buildings that make use of sustainable construction materials and technologies perform better. This is because building in an eco-friendly way results in less waste. Agro-industrial by-products and insulating materials are two examples of sustainable materials that have been put to good use in the climate change mitigation effort and to preserve the environment. Precast components are emphasized as a viable option that is suitable for this purpose and may potentially fulfill the need for housing units. Thus, this study investigated the viability of employing agricultural waste consisting of pomegranate peel waste to produce fired clay bricks. Results demonstrated that the optimum amount of pomegranate peel waste was determined to be 15%, and the optimal firing temperature was determined to be 900 °C. The thermal conductivity of all test samples was lower than that of conventional brick. Furthermore, when compared to conventional wall brick, all the tested samples of manufactured brick reduced energy consumption by 17.55% to 33.13% and carbon dioxide emissions by 7.50% to 24.50%. In addition, the economic feasibility of employing each synthetic sample was evaluated by computing the simple payback time (SPP). It was determined that 1.88–10.74 years were required for the brick samples to provide a return on their initial investment. Due to its ability to decrease heat gain, preserve energy, minimize CO2 emissions, and shorten the payback time, burned clay bricks manufactured from pomegranate peel waste are regarded as a feasible building material. Hence, manufactured bricks are usually considered an exceptional contribution to environmental sustainability.
This study investigates the role of vegetation in enhancing thermal comfort and achieving energy savings in educational building courtyards located in hot, arid climates. The research focuses on an educational building courtyard in New Aswan City, Egypt, and employs a combination of field monitoring and numerical simulations to evaluate the thermal performance of the space. The study utilized the ENVI-met V5.5.1 model for thermal assessment and the Design-Builder software version 6.1.3.007 to quantify the potential energy savings. Nine different vegetation scenarios were proposed and analyzed to identify the most effective strategies for improving the courtyard’s thermal conditions. The results demonstrate that a 60% coverage of the courtyard with Cassia Nodosa vegetation produced the most significant improvements. This scenario led to a decrease of over 25.4 °C in physiological equivalent temperature (PET) and a reduction of more than 31.3 °C in mean radiant temperature (Tmrt). Moreover, the energy savings achieved were approximately 19.2%. Interestingly, the study also observed an unexpected decrease in the temperature mitigation efficacy of Ficus nitida when vegetation coverage was increased from 40% to 60%. This phenomenon can be attributed to the complex interplay between the inherent characteristics of the Ficus nitida species and the microclimatic factors within the courtyard environment. These findings provide valuable insights for designers and architects to integrate effective vegetation strategies into the design of educational building courtyards in hot, arid climates. By enhancing thermal comfort and reducing energy consumption, this approach can contribute to the creation of more sustainable and comfortable learning environments.