%0 Journal Article
%K Building energy use
%K Building simulation
%K Building performance
%K CityBES
%K Urban microclimate
%K Climate resilience
%A Tianzhen Hong
%A Yujie Xu
%A Kaiyu Sun
%A Wanni Zhang
%A Xuan Luo
%A Barry Hooper
%B Urban Climate
%D 2021
%G eng
%P 100871
%R 10.1016/j.uclim.2021.100871
%T Urban microclimate and its impact on building performance: A case study of San Francisco
%U https://www.sciencedirect.com/science/article/abs/pii/S2212095521001012
%V 38
%8 07/2021
%! Urban Climate
%X <p>Urban microclimate exerts an increasing influence on urban buildings, energy, and<br />sustainability. This study uses 10-year measured hourly weather data at 27 sites in San Francisco,<br />California, to (1) analyze and visualize the urban microclimate patterns and urban heat island<br />effect; (2) simulate annual energy use and peak electricity demand of typical large office buildings<br />and large hotels to investigate the influence of urban microclimate on building performance; (3)<br />simulate indoor air temperature of a single-family house without air-conditioning during the record<br />three-day heatwave of 2017, to quantify the divergence of climate resilience due to urban<br />microclimate effect. Results show significant microclimate effects in San Francisco with up to 11℃<br />outdoor air temperature difference between the coastal and downtown areas on September 1,<br />2017, during the record three-day heatwave. The simulated energy results of the prototype large<br />office and large hotel buildings using the 2017 weather data show over 100% difference in annual<br />heating energy use and 65% difference in annual cooling energy use across different stations; as<br />well as up to 30% difference in peak cooling electricity demand. The impacts on annual site or<br />source energy use are minimal (less than 5%) as cooling and heating in a mild climate are a<br />relatively small portion of overall building energy use in San Francisco. Results also show the<br />microclimate effects influence indoor air temperature of unconditioned homes by up to 5℃. Newer<br />buildings and homes are much less affected by microclimate effects due to more stringent<br />performance requirements of the building envelope and energy systems. These findings inform<br />that San Francisco microclimate variations should be considered in urban energy planning,<br />building energy codes and standards, as well as heat resilience policymaking.</p>