Passive survivability of buildings under changing urban climates across eight US cities

Abstract

In the US, more than 80% of fatal cases of heat exposure are reported in urban areas. Notably, indoor exposure is implicated in nearly half of such cases, and lack of functioning air conditioning (AC) is the predominant cause of overheating. For residents with limited capacity to purchase, maintain, and operate an AC system, or during summertime power outages, the ability of buildings to maintain safe thermal conditions without mechanical cooling is the primary protective factor against heat. In this paper, we use whole-building energy simulations to compare indoor air temperature inside archetypical single-family residential buildings without AC at the start and middle of the century in eight US cities. We ran the models using hourly output from 10 year regional climate simulations that explicitly include heating from mid-century projections of urban development and climate change under a 'business-as-usual' emissions scenario. Moreover, to identify the impacts from evolving construction practices, we compare different versions of building energy standards. Our analysis shows that summertime overheat time may increase by up to 25% by the middle of century. Moreover, we find that, while newer building energy codes reduce thermal comfort under moderate outdoor weather, they perform better under extreme heat.

Reducing the health effects of hot weather and heat extremes: from personal cooling strategies to green cities

“…48,49 Such high temperature and humidity combinations have not been reported in any major global heat extreme event between 2007 and 2019 (figure 2), but the translation of outdoor (landscape and urban level) conditions to the indoor environment is heavily dependent on characteristics at the building level of the heat cascade. 58 Very high air temperatures (>45°C) are usually accompanied by lower humidity (figure 2). Because most sweat readily evaporates without sup plemental airflow in these conditions, fan use worsens physiological heat strain 47 and should not be recom mended.…”

The Role of Individual and Small-Area Social and Environmental Factors on Heat Vulnerability to Mortality Within and Outside of the Home in Boston, MA

“…The risk of major and widespread power outages that affect a large number of customers and that would result in "heat disasters" appears to be growing [19]. Research has shown that the summertime overheating of residential buildings may increase by upwards of 25% by the middle of the 21st century [20].…”

Spatial Disparities in Air Conditioning Ownership in Florida, United States

“…Hotter and more humid air masses in uence subtropical and tropical climate areas more than other climates [24]. In these areas, indoor environments without an adequate cooling system can cause indoor overheating [25]. In Florida, statewide average temperatures are higher than 30 degrees Celsius during the summer, and some residents lack AC units to manage cool indoor environments.…”