Data were collected in 70 detached houses built in 2011‐2017 in compliance with the mechanical ventilation requirements of California's building energy efficiency standards. Each home was monitored for a 1‐week period with windows closed and the central mechanical ventilation system operating. Pollutant measurements included time‐resolved fine particulate matter (PM_2.5) indoors and outdoors and formaldehyde and carbon dioxide (CO₂) indoors. Time‐integrated measurements were made for formaldehyde, NO₂, and nitrogen oxides (NO_X) indoors and outdoors. Operation of the cooktop, range hood, and other exhaust fans was continuously recorded during the monitoring period. Onetime diagnostic measurements included mechanical airflows and envelope and duct system air leakage. All homes met or were very close to meeting the ventilation requirements. On average, the dwelling unit ventilation fan moved 50% more airflow than the minimum requirement. Pollutant concentrations were similar to or lower than those reported in a 2006‐2007 study of California new homes built in 2002‐2005. Mean and median indoor concentrations were lower by 44% and 38% for formaldehyde and 44% and 54% for PM_2.5. Ventilation fans were operating in only 26% of homes when first visited, and the control switches in many homes did not have informative labels as required by building standards.

中文翻译：

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加利福尼亚州房屋的室内空气质量符合法规要求的机械通风。

根据加州建筑节能标准的机械通风要求，收集了2011-2017年建造的70栋独立房屋的数据。在关闭窗户和运行中央机械通风系统的情况下，对每个房屋进行为期1周的监控。污染物测量包括室内和室外的时间分辨细颗粒物（PM _2.5）以及室内的甲醛和二氧化碳（CO ₂）。对甲醛，NO ₂和氮氧化物（NO _X）在室内和室外。在监视期间，将连续记录炉灶，抽油烟机和其他排气扇的运行情况。一次性的诊断测量包括机械气流以及外壳和管道系统的空气泄漏。所有房屋均达到或非常接近通风要求。平均而言，居住单元通风风扇的气流比最低要求多出50％。污染物浓度与2006-2007年对2002-2005年建造的加利福尼亚新房的研究所报告的浓度相似或更低。甲醛的室内平均浓度和中位数浓度分别降低44％和38％，PM _2.5的室内平均浓度中值分别降低44％和54％。初次造访时，通风风扇仅在26％的房屋中运转，并且许多房屋的控制开关没有建筑标准要求的信息标签。