Wahid Maref

This review explores the pressing need for decarbonization strategies in the off-grid Indigenous communities of Northern Quebec, particularly focusing on Nunavik, where reliance on diesel and fossil fuels for heating and electricity has led to disproportionately excessive greenhouse gas emissions. These emissions underscore the urgent need for sustainable energy alternatives. This study investigates the potential for improving building energy efficiency through advanced thermal insulation, airtight construction, and the elimination of thermal bridges. These measures have been tested in practice; for instance, a prototype house in Quaqtaq achieved over a 54% reduction in energy consumption compared to the standard model. Beyond efficiency improvements, this review assesses the feasibility of renewable energy sources such as wood pellets, solar photovoltaics, wind power, geothermal energy, and run-of-river hydropower in reducing fossil fuel dependence in these communities. For instance, the Innavik hydroelectric project in Inukjuak reduced diesel use by 80% and is expected to cut 700,000 t of CO₂ over 40 years. Solar energy, despite seasonal limitations, can complement other systems, particularly during sunnier months, while wind energy projects such as the Raglan Mine turbines save 4.4 million liters of diesel annually and prevent nearly 12,000 t of CO₂ emissions. Geothermal and run-of-river hydropower systems are identified as long-term and effective solutions. This review emphasizes the role of Indigenous knowledge in guiding the energy transition and ensuring that solutions are culturally appropriate for community needs. By identifying both technological and socio-economic barriers, this review offers a foundation for future research and policy development aimed at enabling a sustainable and equitable energy transition in off-grid Northern Quebec communities.

Achieving both indoor environmental quality (IEQ) and energy efficiency in school buildings remains a challenge, particularly in older structures where renovation strategies often lack site-specific validation. This study evaluates the impact of energy retrofits on a 1970s primary school in France by integrating in situ measurements with a validated numerical model for forecasting energy demand and IEQ. Temperature, humidity, and CO₂ levels were recorded before and after renovations, which included insulation upgrades and an air handling unit replacement. Results indicate significant improvements in winter thermal comfort (PPD < 20%) with a reduced heating water temperature (65 °C to 55 °C) and stable indoor air quality (CO₂ < 800 ppm), without the need for window ventilation. Night-flushing ventilation proved effective in mitigating overheating by shifting peak temperatures outside school hours, contributing to enhanced thermal regulation. Long-term energy consumption analysis (2019–2022) revealed substantial reductions in gas and electricity use, 15% and 29% of energy saving for electricity and gas, supporting the effectiveness of the applied renovation strategies. However, summer overheating (up to 30 °C) persisted, particularly in south-facing upper floors with extensive glazing, underscoring the need for additional optimization in solar gain management and heating control. By providing empirical validation of renovation outcomes, this study bridges the gap between theoretical predictions and real-world effectiveness, offering a data-driven framework for enhancing IEQ and energy performance in aging school infrastructure.

Montreal experiences a significant urban heat island (UHI) effect, potentially intensified by its dense urban structure, varied vegetation, and demographic distribution, leading to substantial outdoor thermal discomfort, especially during heatwaves. To quantify this, measured thermal landscape data were analyzed over several months in Montreal, including heatwave periods, and outdoor thermal comfort was assessed using the humidex, discomfort index, heat index, and temperature–humidity index. The results indicated notable temperature and humidity variations across the city, with the exceedance of thermal comfort index thresholds being significantly higher during heatwaves (humidex: 10.83%, discomfort index: 53.33%, heat index: 24.77%, temperature–humidity index: 36.67%) compared to normal periods. This study provides a quantitative evaluation of UHI-induced outdoor thermal discomfort in Montreal, emphasizing its severity during heatwaves and analyzing the influence of urban density, vegetation, and anthropogenic emissions, thus offering valuable insights for urban planning strategies to mitigate public health impacts.

In recent years, the implementation of decarbonization measures in response to global warming has brought significant attention to the building sector, recognizing it as a major contributor to CO ₂ emissions. This study explores the unique combination of solid-solid phase change material (SSPCM) in double-glazed window (DGW) subjected to different climates, offering a novel approach to enhancing energy efficiency of glazing system, thus Building envelope. To assess the system’s energy performance, numerical simulations were performed across a range of temperature conditions. These have included extreme temperatures of the hottest and coldest days of the year, as well as different weather patterns such as sunny and cloudy days in the cities of Montreal, Vancouver, and Miami. The obtained results demonstrated that during summer sunny conditions, energy savings were achieved in both Montreal (17.5%) and Vancouver (23.5%), while Miami experienced energy losses (5.3%). On summer cloudy days, energy savings were observed exclusively in Vancouver (53.6%), whereas energy losses occurred in both Montreal (356%) and Miami (36.3%). Under winter sunny conditions, all cities showed energy losses due to the SSPCM blocking beneficial direct solar radiation during the daytime (Montreal: 18.8%, Vancouver: 3.1%, and Miami: 270%). Conversely, during winter cloudy conditions, energy savings were noted in all cities, as the SSPCM helped retain warm indoor air (Montreal: 7.0%, Vancouver: 12.4%, and Miami: 26.2%). The results revealed that complete visual transparency can be achieved during office hours, enhancing the suitability of the proposed glazing system for commercial applications. These findings can help in designing energy-efficient glazing systems subjected to various climatic conditions.

This research investigates the energy efficiency of a novel double-glazing system incorporating solid–solid phase change materials (SSPCMs), which offer significant advantages over traditional liquid–solid phase change materials. The primary objective of this study is to develop a 3D numerical model using the finite volume method, which will be followed by a parametric study under real climatic boundary conditions. A proposed double-glazing setup featuring a 2 mm layer of SSPCM applied on the inner glass pane within the air gap is modeled and analyzed. The simulations consider various transient temperatures and ranges of the SSPCM to evaluate the energy performance of the system under different weather conditions of Miami, FL during the coldest and hottest days of the year, both in sunny and cloudy conditions. The results demonstrate a notable improvement in energy performance compared to standard double-glazing windows (DGWs), with the most efficient SSPCM configuration exhibiting a phase transition temperature and range of 25 °C and 1 °C, respectively. This configuration achieved energy savings of 24%, 26%, and 23% during summer sunny, winter sunny, and winter cloudy days, respectively, relative to DGWs during cooling and heating degree hours. However, a 3% energy loss was observed during summer cloudy days. Overall, the findings of this study have shown the potential for energy savings by incorporating SSPCM with suitable thermophysical properties into double-glazing systems.

The search for environmentally friendly and low-carbon-footprint construction materials continues progressively. Researchers are now interested in innovative materials that connect with the principles of sustainable construction, and materials such as hemp concrete prove to be promising. This article presents the results of a study that aimed to evaluate the hygrothermal performance of hemp concrete integrated into the building envelope using the hygrothermal tool WUFI Pro 6.2. The simulation model was compared and verified with existing models before its utilization for this study. The results of this verification were in good agreement, which gave us more confidence in its application for further parametric studies of building envelopes in hot climate zones. Three wall systems were simulated: (i) a wall system with hemp concrete, (ii) a compressed earth block wall, and (iii) a cement block wall. The most important variables used in the simulations were the hygrothermal properties of the materials or wall components and the incident solar radiation. The simulation results showed that hemp concrete has good thermal performance and temperature and humidity regulation capabilities of the building envelope. The interior surface temperatures of the hemp concrete walls were between 22.1 °C and 24.6 °C compared to the compressed earth block and cement block walls, where the surface temperatures were between 22.0 °C and 27 °C and between 21.2 °C and 28.7 °C, respectively, and between 23 °C and 45 °C for the exterior temperatures. These values remain the same with the increase in exterior temperatures for hemp concrete walls. In conclusion, hemp concrete could be a great alternative material for use in construction for hot climate zones.