Quantifying the Impact of Energy-Efficient Housing Interventions on Indoor Air Quality and Energy Consumption Using Energy, Airflow, and IAQ Co-Simulation

摘要

BACKGROUND. Residential weatherization retrofits can provide important economic benefits to low-income residents, but can also impact indoor air quality (IAQ). Mechanical ventilation can mitigate IAQ impacts, but can lead to higher energy costs. Furthermore, the combined impact of these measures across diverse multifamily environments has not been well-established. Simulation models provide an efficient means of evaluation, but to date modeling studies have focused on either IAQ or energy without comprehensively evaluating lAQ-energy tradeoffs. METHODS. We use a novel co-simulation model of CONTAM and EnergyPlus to simulate the impacts of minimum and high-performance weatherization and ventilation standards on indoor PM2.5, gas consumption, and electricity utilization in typical midrise multifamily buildings in the U.S. Unlike previous energy- or IAQ-only models, our co-simulation model can account for the interdependencies between heat transfer, airflows, and contaminant transport in multifamily buildings. We simulated 648 factorial combinations of weatherization (insulation and sealing), ventilation (exhaust and supply ventilation, local cooking exhaust, and HVAC filtration), and indoor PM2.5 sources (cooking, smoking, infiltration) to identify IAQ-energy 'win-win' scenarios as well as scenarios with IAQ-energy tradeoffs. DISCUSSION. We found that IAQ and energy impacts varied by retrofit performance level, mechanical ventilation, indoor sources, and weather. Combined weatherization and ventilation measures meeting minimum standards generally led to energy savings (ranging from 15% to 45%) and reductions in total indoor PM2.5 (ranging from -1 μg/m3 to -29 μg/m3). Meanwhile, some retrofit combinations exceeding minimum standards led to IAQ disbenefits for heavy cooking or smoking homes or an increase in energy costs due to added supply ventilation. Results demonstrate the utility of our model in identifying interventions that provide both energy and IAQ benefits.