Anthropogenic heat (AH) from buildings contributes to the urban heat island effect and increases the temperature in urban areas. This temperature increase results in more building cooling demands and more air-conditioning use produces more waste heat to the urban environment, forming a positive feedback. Global climate change can further intensify this feedback process. It’s thus crucial to investigate the conditions under which this feedback process is substantial, as well as mitigation strategies for building AH.
Commonly, building AH is analyzed with either top-down or bottom-up approaches. The top-down approach uses energy consumption or population density as a proxy for building heat emission. Such data are more readily available, making top-down methods a good fit for analysis covering large urban domains, however, it ignores temporal dynamics on the scales of minutes to hours that result from interactions between building physics and local weather conditions. Bottom-up studies generally use Building Energy Simulation models to directly estimate building heat emissions. Even though such studies usually use prototype building models to reduce the data requirement and the number of simulation runs, they are still relatively computationally intensive.
In this study we use a bottom-up approach to estimate the AH of buildings in Los Angeles County using EnergyPlus for a high-impact heat wave in 2018. We use WRF-UCM, a well-established urban micro-climate modeling framework to simulate the local urban micro-climate dynamics and conduct extensive validation to ensure a reasonable performance by these models. The results could help shed light on the role of AH in urban micro-climate dynamics during extreme heat events and assist local governments to plan emergency response during heat waves and develop long-term mitigation strategies to reduce building AH and the magnitude of the AH-temperature feedback loop. The data set to be published along with this study will potentially benefit future research of urban-scale building heat emissions.