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The city of Kitchener, Ontario, has installed a heat recovery loop in one indoor pool, all indoor swimming pools use pool covers, and two have solar heating. Energy is saved in two ice arenas by low-emissivity ceilings, and in the largest arena by a heat recovery system. (MLF)

A recent study of the health of Indigenous children in four First Nations Communities in remote northwestern Ontario found that 21% of children had been admitted to hospital for respiratory infections before age 2 years. Here we report a detailed analysis of the housing conditions in these communities. We employed a variety of statistical methods, including linear regression, mixed models, and logistic regression, to assess the correlations between housing conditions and loadings of biocontaminants (dust mite allergens, fungal glucan, and endotoxin) and indoor concentrations of PM2.5, CO2, benzene, and formaldehyde. The houses (n = 101) were crowded with an average of approximately 7 people. Approximately 27% of the homes had sustained CO2 concentrations above 1500 ppm. Most homes had more than one smoker. Commercial tobacco smoking and the use of non-electric heating (e.g., wood, oil) were associated with increased fine particle concentrations. Over 90% of the homes lacked working Heat Recovery Ventilators (HRVs), which was associated with increased fine particle concentrations and higher CO2. Of the 101 homes, 12 had mold damage sufficient to increase the relative risk of respiratory disease. This resulted from roof leaks, through walls or around the windows due to construction defects or lack of maintenance. A similar percentage had mold resulting from condensation on windows. Endotoxin loadings were much higher than any previous study in Canada. This work provides evidence for the need for more effort to repair existing houses and to ensure the HRVs are properly installed and maintained. [ABSTRACT FROM AUTHOR]

The performance of air-type PVT and BIPVT collectors has been extensively studied. As a system that generates heat and power, PVT collector testing has some particularities especially when using air as a heat recovery fluid and a building-integrated design (BIPVT). The electrical and thermal experimental performance of such collectors are currently being evaluated using in-house methods or PV and/or solar thermal collector standards. The use of a wide range of methods, testing conditions and experimental setups makes it difficult not only to compare the performance of different designs, but also to have confidence in the results obtained. This study evaluates the performance of an air-type BIPVT collector with in-channel perforated baffle plates for heat transfer enhancement designed for a building-integrated façade. As part of a joint research project between Korea and Canada, the proposed collector's performance was evaluated through indoor (Canada) and outdoor experiments (Korea). Limited comparison of the results obtained with the two testing methods could be performed due to differences in environmental testing conditions, BIPVT collector area and experimental setup. Nevertheless, the limited measurement points under comparable testing conditions indicate that the results from the indoor and outdoor experiments have a similar trend. A comparison between the studied collector having a full PV absorber and a BIPVT collector with a hybrid PV/solar thermal collector absorber using a similar indoor experimental setup and testing conditions was performed. It showed that under still air conditions, for an irradiance level of approximately 820 W/m2 and with a low flow rate, the BIPVT collector with a hybrid PV/solar thermal absorber has a thermal and electrical efficiency of 25.1% and 5.9%, respectively. Under similar conditions, the BIPVT collector with a full PV absorber has a thermal efficiency of 23.9% and an electrical efficiency of 13.5%. At higher flowrates, both units have similar thermal efficiencies, however, the BIPVT collector with a PV absorber remains with an electrical efficiency that is more than double that of the unit with a hybrid PV/solar thermal absorber. [ABSTRACT FROM AUTHOR]

Increasing temperatures associated with climate change will be the next challenge for crop improvement, especially for turfgrass species that are often grown in urban green spaces. Previous research on turfgrass heat stress tolerance has been limited to a small number of species and cultivars with different heat stress conditions between studies; therefore, we assessed heat stress tolerance of 34 turfgrasses representing 14 species. Four replicates of each entry were established for at least 12 wk and then subjected to 49 d of heat stress (35/25 °C day/night) followed by a 4 wk recovery period (25/15 °C day/night). Turfgrass entries were assessed using the normalized difference vegetative index, the percentage of green obtained with digital image analysis, and membrane stability estimated by electrolyte leakage. Buffalograss [Bouteloua dactyloides (Nutt.) J.T. Columbus], Kentucky bluegrass (Poa pratensis L.), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort], and slender creeping red fescue (Festuca rubra ssp. littoralis) were more tolerant of heat stress than the other species. The Canada bluegrass (Poa compressa L.), blue grama [Bouteloua gracilis (Willd. ex Kunth.) Lag. ex Griffiths], and smooth brome (Bromus inermis Leyss.) cultivars were all tolerant of heat stress; however, only one cultivar for these three species was tested, making species‐wide generalizations difficult. In some cases, the cultivars and/or selections within a given species differed in heat stress response. Almost all entries were able to recover from the heat stress by the end of the recovery period. Altogether, we were able to identify turfgrasses that should perform adequately in high‐temperature urban environments. [ABSTRACT FROM AUTHOR]

Financial risks and environmental concerns associated with fossil fuel dependency are motivating mining companies to improve their energy profile. Diesel generators are vastly used as the main power source in off-grid mining operations located in the cold climate regions of Canada and other northern areas of the globe. However, almost 65% of the heat generated in the combustion chambers of a diesel generator is rejected as waste heat, a sizeable portion of which is discarded through the exhaust. This study presents a techno-economic analysis on the feasibility of recovering waste heat from exhaust streams of diesel generators by identifying their fuel consumption and recoverable thermal energy available in their exhaust. The potential energy and economic savings are investigated by reviewing the performance of the proposed diesel exhaust heat recovery system through a series of parametric studies, especially on temperature conditions, heat exchanger effectiveness, mine size and applications. The analysis shows that an extensive fraction of the heat demand of the mine could be supplied by the system. For pre-heating the mine intake air in cold climate regions, these savings could be as high as several millions of dollars. Consequently, the present work shows how deploying such diesel exhaust heat recovery strategy can lead remote mining towards a more energy efficient, economic and sustainable operation while gradually reducing carbon footprint in the life cycle of mines. [ABSTRACT FROM AUTHOR]

In this paper, a novel multigenerational integrated system that is able to produce five useful commodities, such as freshwater, space heating, hot water, power and hydrogen for a community, is proposed and investigated. The system uniquely covers heat storage by molten salt heat storage along with hydrogen production by magnesium-chlorine (Mg–Cl) based thermochemical cycle. Additionally, the present system has a multi-effect desalination plant to provide freshwater community needs. A solar power tower is offered due to its capability of harvesting high energy levels. The heat recovered by the solar power receiver is passed through an organic Rankine cycle (ORC) to meet the need for the high-temperature level that is required for the thermochemical cycle. The molten salt storage tanks are used to offset the mismatch between demand and supply for the necessary energy to run the system in case of the absence of solar irradiation. The suggested system is intended to leverage solar and geothermal energy sources to generate practical necessities like power, heat, and hot water for residential applications of a projected community. The system is then analyzed in detail thermodynamically in the context of exergy and energy approaches. In addition, the subsystems are analyzed parametrically to study the performance of the overall system to observe how the ambient and working conditions change the system efficiencies. The city of Vancouver in Canada is selected as the potential location where the system performance assessment is carried out accordingly. As a result of the present thermodynamic analysis, the energetic and exergetic efficiencies for the system are obtained as 45.45% and 52.32%. The total exergy destruction rate is another exergy metric to compare both versions, where the rate of 163967.39 kW exergy destruction is obtained for the overall system. • A novel multigenerational integrated system developed with the Mg–Cl thermochemical cycle • Energy and exergy approaches and thermodynamics used to analyze the system efficiencies • Parametric study is carried out to observe the various effects on system performance. • The energy and exergy efficiencies found 45.45% and 49.65% to produce hydrogen, power, fresh water, and heat. [ABSTRACT FROM AUTHOR]

With the present leaning towards well-insulated and airtight energy-efficient buildings and houses, air-to-air heat/energy exchangers have become very important for maintaining a good indoor air quality (IAQ) via continuous mechanical ventilation along with decreasing energy needed to condition the inbound fresh air. The present study aims to experimentally evaluate the performances of a dual-core ERV-HRV system in terms of heat and energy recovery in residential environment under Atlantic Canada weather. An IoT platform was designed and integrated to this ventilation system in order to collect and log real-time data. Moreover, this paper presents a detailed mathematical model of the proposed system to predict its energy exchange efficiency, using the effectiveness-NTU (i.e. ε - N T U) approach. The model was subsequently validated against experimental measurements within laboratory environment. As proved by experimental data, the theoretical model can predict, with a relative discrepancy less than 10%, the system energy exchange efficiency. Results from a real house located at Sainte-Anne-de-Kent in New-Brunswick, Canada are presented in this study, and the system efficiency was assessed under hot and cold weather conditions. The research findings show that, in the winter, the measured sensible and latent efficiencies are in ranges of 65.66–85.05% and 38.46–58.96%, respectively. Whereas, for the summer season, the corresponding effectiveness ranged from 31.7% to 85.72%, and from 68.51% to 92.69%, respectively. As consequence, the experimental results analysis revealed that the proposed dual-core exchanger is efficient during both heating and cooling seasons. [ABSTRACT FROM AUTHOR]

Health Canada's cross-Canada residential radon survey from 2012 demonstrated roughly 7% of Canadian homes contain radon levels above the national guideline of 200 Bq/m3. British Columbia (BC) is the first province in Canada to mandate a full stack passive soil depressurization (PSD) system installed within homes in radon prone areas. All other provinces within Canada require a sealed and capped rough-in pipe. In this study, PSD systems were installed in fifteen new construction homes and retrofitted in six existing homes across three provinces in Canada. This study demonstrated the potential of well-designed PSD systems to reduce radon exposure in Canadian homes, reducing indoor radon concentration below 200 Bq/m3 in all 21 homes during multiple 30-day periods. During the winter, the PSD system was less effective in several new construction homes, whereas it appeared to operate more consistently in retrofitted existing homes. Further investigation revealed homes with a heat recovery ventilator (HRV), a ground floor bathroom, or no stack insulation were susceptible to degradation in the PSD system performance from the shoulder to winter season. Such performance degradation might be attributed to 1) HRV defrost mode causing a reduction in the ventilation air supply, 2) unsealed ground floor cut outs for the bathroom increasing the building stack effect and inducing more radon ingress through the floor slab during the winter, and 3) stacks without insulation causing frost and restricting the airflow within the stack. Image 1 • Evaluated performance of passive sub-slab depressurization in 21 Canadians homes. • Effectively reduced the radon concentration to below 200 Bq/m3 in all homes. • Performance during the winter is impacted by building and system design. [ABSTRACT FROM AUTHOR]

• A rock-pile waste heat storage is proposed, and its corresponding numerical model is developed. • Both fluid flow and heat transfer are validated against experimental data. • Local Thermal Equilibrium and Non-Equilibrium approaches are compared. • Parametric studies are performed on thermo-physical properties. • Payback time analysis is performed, and the system is economically justified. Remote communities in arctic climates are solely dependent on diesel generators for continuous power supply due to their detached loci from national power gridlines or natural gas pipelines. Moreover, to get along with the harsh, long winters, these communities directly or indirectly depend on fossil-fuel based heating systems. Due to the lower efficiency of the conventional diesel engines, these generators discard a significant amount of heat through the exhaust. Occasionally, during the wintertime, this waste heat from the exhaust is used directly as a heat source after recovery. However, during summer, when the heating demand is lower or nil, this heat is commonly discarded, and its energy potential wasted. A rock-pile based seasonal thermal energy storage is a viable solution that can sustainably resolve this issue. This paper presents a validated numerical study that focuses on the coupling of a waste heat recovery system to a diesel exhaust stream offering a performance assessment of the proposed rock-pile waste heat storage system in a remote, off-grid community located in northern Canada. It examines the impacts of local thermal equilibrium versus non-equilibrium approaches as well as temperature-dependent properties, variation of air mass flow rate, particle size and finally the thermo-physical properties on the proposed model. The presented results show that air should be treated as an ideal gas and that the local thermal non-equilibrium approach should be used for its considerably higher accuracy. Techno-economic assessment of the system resulted in a relatively short payback period of less than six years. [ABSTRACT FROM AUTHOR]