• Energy Research

The possibility of obtaining large data set of infrared images during building and urban envelope surveys require the development of fast and effective ways to process their content. This study presents a novel U-NET convolution neural network (CNN) deep learning (DL) model for the identification of envelope deficiencies on a data set of infrared (IR) thermographic images of building envelopes. A data set of images acquired with an unmanned aerial vehicle (UAV) were used with supplementary segmentation masks created for appropriate U-NET modelling application. This data preparation process is presented followed by an in-depth review of the CNN architecture used for the segmentation process. The Python3 code developed for this study is simplified for easier application by non-data-science researchers. The results of this research show high accuracy. However, large data set are needed to better train the CNN-DL model.

In recent years, there has been a heightened emphasis improving visual comfort and energy efficiency. Various solutions have been explored to achieve high-performance design. Shading devices play a crucial role in enhancing building performance by redusing solar gains, excessive daylight, and improving both energy efficiency and occupants' visual comfort. This research aims to investigate the effect of facade geometry on visual comfort and energy consumption in four different climates of Iran and categorize each variable based on effectiveness for each location. Parametric office modeling was done by using Grasshopper and Rhino software. Then, the effect of the facade on the interior lighting and energy consumption was analyzed by Radiance, Daysim, and EnergyPlus calculation engines. The Non-Dominated Sorting Genetic Algorithm (NSGA-II) was selected to optimize solutions, minimize energy consumption, maximize useful daylight illuminance, and view quality. In addition, the methodology was used to explore the framework for optimizing office facade design in Iran's diverse climatic zones. The simulation results indicate that window-to-wall ratio and inclined wall were essential for balancing daylighting performance and energy consumption. This research stated that using a self-shading design could increase the quality of view up to 75% while reducing energy consumption and the risk of glare. Results proposed a design framework to improve visual comfort and save energy. The rotating façade's wall 10°-30° reduced cooling energy demand and energy usage intensity in selected models. So, an inclined wall could be an efficient shading device to improve building's performance in Iran.

The deleterious effects of noise pollution on public health have been well documented, with traffic noise being identified as a significant contributor to stress and adverse impacts on the human body and mind. In this study, sound levels at 12 different points in Al-Oqailat Park in Buraydah, Saudi Arabia, were measured using a sound level meter (SLM), with the study’s primary objective being to conduct this measurement. The experimental results were then compared with perception measurements collected from users who frequently visited Al-Oqailat park. Sound measurements were taken in four different zones (A, B, C, and D) during rush hours between 1:30 p.m. and 5:20 p.m. It was found that noise levels at point A1 peaked at 79 dBA at 4:40 p.m., while the lowest level recorded was 41.1 dBA at point D2 at 2:35 p.m. The range of noise levels varied between 79 and 41 dBA, with a rate of decline of 48.10%. Zones A and B seemed to have the highest noise levels during rush hours, since they were located closest to King Fahd Road and Al-Adl Street, while zone D exhibited the lowest noise levels due to its location as a parking lot for Buraydah Court. An intermediate noise level was found in zone C, in the middle of Al-Oqailat park. The people perception results, completed by 84 park visitors, showed that zone A was identified as having exceptionally high noise levels compared to the other zones, with zone D having the lowest levels. These results were consistent with the experimental findings and reflected that the points along King Fahd Road and Al-Adl Street had the highest noise levels. Overall, the research highlighted the dominance of car traffic and horns as the primary sources of noise pollution in and around Al-Oqailat Park, emphasizing the significance of meticulous site selection for parks in urban areas.

This study investigates the use of air source heat pumps (ASHPs) in detached residential homes in cold climates. The study aims to assess if ASHPs can provide reliable heating responses in mild, cold, and very cold climate zones across Canada. Moreover, it investigates how the use of ASHPs in a warming climate will affect the energy use intensity (EUI) and greenhouse gas (GHG) emission compared to the current most-commonly adopted gas furnaces. Different systems are compared under current and future climate scenarios. Findings indicated that ASHP systems would be best suited for residential use in Vancouver (zone 5A) across different scenarios (present 1998–2014, near future 2030–2041, and far future 2056–2075) due to the milder temperatures annually. Reversely, the colder climates of Toronto and Quebec City may require supplementing sizing of the heating systems and would result in lower efficiency and high GHG due to the higher emission factors of non-electrical power demand.

Abstract Green roofs have been proposed for sustainable buildings in many countries with different climatic conditions. A state-of-the-art review of green roofs emphasizing current implementations, technologies, and benefits is presented in this paper. Technical and construction aspects of green roofs are used to classify different systems. Environmental benefits are then discussed mainly by examining measured performances. By reviewing the benefits related to the reduction of building energy consumption, mitigation of urban heat island effect, improvement of air pollution, water management, increase of sound insulation, and ecological preservation, this paper shows how green roofs may contribute to more sustainable buildings and cities. However, an efficient integration of green roofs needs to take into account both the specific climatic conditions and the characteristics of the buildings. Economic considerations related to the life-cycle cost of green roofs are presented together with policies promoting green roofs worldwide. Findings indicate the undeniable environmental benefits of green roofs and their economic feasibility. Likewise, new policies for promoting green roofs show the necessity for incentivizing programs. Future research lines are recommended and the necessity of cross-disciplinary studies is stressed.

Abstract The development of innovative materials aiming to achieve energy savings is a main focus in the building technology sector. In this context, aerogel-enhanced products are often indicated as promising materials for increasing the thermal resistance of the building envelope. In particular, aerogel blankets have already started showing their effectiveness in retrofitting projects, while the development and adoption of aerogel-enhanced renders and aerogel-incorporating glazing systems is progressing. Based on the state of the art, this paper describes several new aerogel-enhanced systems that have been developed over the last few years at Ryerson University in Toronto, ON. In particular, the paper presents the recent results regarding aerogel-enhanced plasters, lightweight concretes, blankets, and glazing systems. Thermal characterization tests of these new materials confirm the superior performance for building retrofits. For example, the thermal conductivity of plasters with more than 80%vol. aerogel is below 0.025 W/(mK), a tenth of the respective value for traditional plasters, while mortars with more than 30%vol. aerogel show a thermal conductivity as low as 0.23 W/(mK). The newly presented aerogel-based systems are then assessed for the retrofitting project of an educational building located in Toronto. An extensive energy audit was conducted through measurements of the envelope thermal characteristics, the building airtightness, and several indoor environmental parameters. The audit helped to build an accurate energy model that was used for analyzing the energy consumptions of the building and assessing several energy saving measures. The study showed that high thermal resistance values could be obtained installing thin aerogel-enhanced products in the opaque and transparent envelope, with overall building energy savings up to 34%, with limited impacts and interruptions on the building functionality and internal usable space. However, the high costs of aerogel-enhanced products made their payback times of several decades and represented a barrier for the adoption of most of the systems presented in this paper.

Abstract Aerogel-enhanced materials are known to have significantly lower thermal conductivity than traditional insulating materials. However, given the lack of long-term experiences with aerogel-enhanced products, the consistency of their superior thermal performance under the effect of the various climatic aging processes is still unknown. This study describes the effects of accelerated aging processes in laboratory conditions over the thermal performance of aerogel-enhanced insulating materials. Several products including aerogel-enhanced plasters, blankets, and boards, were exposed to different climatic accelerated stresses, which exceeded typical use conditions. The tests included freeze-thaw cycles, elevated temperature, high humidity levels, and the exposure to cycles of high UV levels alternated to high temperature and moisture levels. The thermal properties of the products before, during, and after the accelerated aging periods were measured. The Peck model, Arrhenius equation, and Coffin-Manson relation were hence employed to correlate the accelerated aging results with the corresponding real service conditions. The paper discusses the acceleration factors of the aging tests and their calculation methods. The long-term performance of the products is quantified through the changes of their thermal conductivity measured over wide temperature ranges. The results show that for the different investigated materials, the increase in the thermal conductivity over the pristine conditions is typically below 10% for aging exposure corresponding to 20 years in typical conditions. Finally, this study suggests that despite some aging-driven degradation, the thermal conductivity of aerogel-enhanced materials after aging remains significantly lower than that of non-aged traditional insulating materials.