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[Display omitted] • Variation in energy use and occupancy patterns using monitored data is determined. • Non-HVAC loads increased by 8% on average compared to loads in pre-COVID months. • Building energy simulation is performed for old normal and new normal occupancies. • Annual increase in electricity of 16.4% and decrease in natural gas by 7.6%. • Energy upgrade ranking is affected by occupancy and stakeholder preference. Stringent lockdowns have been one of the defining features of the COVID-19 pandemic. Lockdowns have brought about drastic changes in living styles, including increased residential occupancy and telework practices predicted to last long. The variation in occupancy pattern and energy use needs to be assessed at the household level. Consequently, the new occupancy times will impact the performance of energy efficiency measures. To address these gaps, this work uses a real case study, a two-story residential building in the Okanagan Valley (British Columbia, Canada). Further, steady-state building energy simulations are performed on the HOT2000 tool to evaluate the resiliency of energy efficiency measures under a full lockdown. Three-year monitored energy data is analyzed to study the implications of COVID-19 lockdowns on HVAC and non-HVAC loads at a monthly temporal scale. The results show a marked change in energy use patterns and a higher increase in May 2020 compared to the previous two years. Calibrated energy models built on HOT2000 are then used to study the impacts of pre-COVID-19 (old normal occupancy) and post-COVID-19 (new normal occupancy) on energy upgrades performance. The simulations show that under higher occupancy times, the annual electricity use increased by 16.4%, while natural gas use decreased by 7.6%. The results indicate that overall residential buildings following pre-COVID-19 occupancy schedules had higher energy-saving potential than those with new normal occupancy. In addition, the variation in occupancy and stakeholder preferences directly impact the ranking of energy efficiency measures. Furthermore, this study identifies energy efficiency measures that provide flexibility for the decision-makers by identifying low-cost options feasible under a range of occupancy schedules. [ABSTRACT FROM AUTHOR]

Occupant behavior in residential buildings has a direct impact on the effectiveness of energy-saving measures. In order to realize a buildings' carbon mitigation targets, the impact of individual occupancy profiles needs to be integrated with building simulation models. This paper introduces a decision support framework as a potential solution to make energy performance upgrade choices based on different occupancy profiles. This framework has been demonstrated through a case study of two single-family detached homes in Canada, which were highly instrumented with sensors for monitoring energy input and output. The case studies represented two common occupancy profiles-(1) a family of four (consisting of 2 working adults and 2 teenagers); and (2) a retired couple. Firstly, calibrated energy models were developed by using one-year energy use data collected through an intrusive load monitoring technique. Secondly, energy upgrade combinations were considered for each profile and tested for additional investment, payback period and greenhouse gas (GHG) emissions. Lastly, the most suitable combination of energy upgrade for each profile was ranked using a multi-criteria decision-making method (e.g., TOPSIS). Results indicated that the retired couple used more energy than the family of four and required energy upgrades with usually higher payback periods to achieve the same level of GHG emission reduction. The results of this research are timely for energy policymaking and developing best management practices, which need to be implemented along with the deployment of more stringent building standards and codes. • A scenario-based framework was developed for residential homes energy upgrades. • It considers occupant behavior and preference in selecting energy upgrades. • Field data is used to represent energy use of a family of four and a stay-at-home retired couple. • Energy upgrades are same under pro-economic choices for two profiles. • Energy upgrades vary under pro-environmental scenarios for two profiles. [ABSTRACT FROM AUTHOR]

Disinfection by-products (DBPs) in public indoor swimming pools (ISP) are a major human health risk concern. Various DBPs control strategies have been developed as an integral part of ISP management; however, these strategies are associated with different energy and resource consumption and environmental impacts. In this study, a process-based life cycle assessment (P-LCA) framework is developed for determining the environmental impacts of DBPs control strategies in ISP management. The developed framework requires ISP operation information such as energy, water, and chemical use, and concentration data under each DBPs control strategy as inputs. The ReCipe2016 midpoint method is used to process the inputs and quantify the lifecycle impacts in terms of three categories: energy, water and chemicals. Based on the outputs, the best strategy is selected using the TOPSIS method. The developed framework is applied to an ISP located in Vancouver (Canada) to evaluate seven DBPs control strategies associated with various air circulation rates. The DBPs concentration data were sourced from a previous sampling campaign. The results show that energy use is the main contributor (87–94%) to the total environmental impacts as compared to chemical and water use (6–13%). Among the tested strategies, reduction of fan speed can yield maximum environmental benefits without compromising the DBPs control performance. On the other hand, supply of 100% fresh air at normal fan speeds results in higher environmental impacts compared to a baseline case despite the lower DBPs releases. The proposed P-LCA framework can facilitate pool operators in selecting low impact DBPs control strategies for sustainable ISP management. • Disinfection by-product control strategies were identified for indoor swimming pools. • A process-based lifecycle assessment framework was proposed for the strategies. • The developed framework was applied to an indoor swimming pool as a case study. • The highest impacts are associated with energy use for pool heating and ventilation. [ABSTRACT FROM AUTHOR]

• Life cycle impacts of thermal desorption treatments of drill cuttings were assessed. • Thermomechanical cuttings cleaner generated the lowest impacts using hydropower. • Rotary drum dryer generated the lowest impacts in onsite drill cutting treatment. • Thermal desorption process contributed 80–90 % of the total impacts of systems. • Regression models were developed to help estimate impacts of different treatments. The life cycle impacts of treatment of typical oil-based drill cuttings (OBDCs) using three low-temperature thermal desorption (LTTD)-based systems, including thermomechanical cuttings cleaner (TCC), screw-type dryer (STD), and rotary drum dryer (RDD), were explored with a case study in British Columbia, Canada. Two energy supply scenarios, including diesel generator-based onsite (scenario i) and hydropower-based offsite (scenario ii) treatments, were considered in the assessment. The results show that RDD generated the lowest life cycle impacts in terms of damages to human health, ecosystems, and resources in scenario i. TCC-scenario ii generated the lowest impacts among all assessed cases, suggesting that using renewable energy can greatly reduce the impacts of LTTD-based OBDCs treatment. Also, net environmental benefits could be achieved considering the reuse of recovered oil, and the highest net environmental benefits were obtained in TCC-scenario ii. The process contribution analysis found that thermal desorption process accounted for 80–95 % of impacts in almost all impact categories. Energy consumption contours and linear regression models were also developed to help drilling waste managers estimate the life cycle impacts of using hydropower-driven TCC to treat OBDCs with different water and oil contents. [ABSTRACT FROM AUTHOR]