建筑大厅，位于华盛顿大学校园，在2005重新装修，从而在设计工作室的自然功能被重新激活。从2007年到2009年，开发了一系列实验方法来评估工作室的自然通风性能，其中包括测量占用时间内的CO²水平和其他室内环境参数。由于CO²可以很容易地测量，因此它可以很好地指示空间中的通风率与居住者数量和相关生物废水水平的关系。结果表明，自然通风空间中的CO²水平经常超过建议水平（Ilyas、Emery和Heerwagen 2010）。还进行了调查，指出居住者中存在与建筑相关的疾病症状，大量居住者对室内环境质量不满意（Ilyas et al。 2012). 根据这些结果，建议在其中一个设计工作室安装一个CO²反馈系统——该系统测量并显示空间中的CO²浓度，并在浓度超过建议水平时指示居住者系统地打开窗户。本文讨论了CO²反馈系统（组件、标准和设置）的基本原理及其在自然通风空间中控制通风率的有效性。引用:ASHRAE论文:2015年ASHRAE年会，佐治亚州亚特兰大

Architecture Hall, located on the University of Washington Campus, was renovated in 2005 whereby the natural function in the design studios was re-activated. A series of experimental methods were developed to assess the natural ventilation performance in the studios from 2007 to 2009, which included measurement of CO2levels and other indoor environmental parameters during occupied hours. Since CO2can be readily measured, it serves as a good indicator of ventilation rates in a space relative to the number of occupants and associated level of bio-effluents. Results indicated that the CO2levels in the naturally ventilated spaces frequently exceeded recommended levels (Ilyas, Emery and Heerwagen 2010). Surveys were also conducted which pointed towards the presence of building related illness symptoms amongst the occupants and a large number of occupants being dissatisfied with the indoor environmental quality (Ilyas et al. 2012). Based on these results, recommendations were made to install a CO2feedback system in one of the design studios – this system measures and displays the CO2concentration in the space and instructs occupants to systematically open windows when theconcentration exceeds recommended levels. This paper discusses the fundamentals of the CO2feedback system (components, criteria and setup) and its effectiveness in controlling the ventilation rates in the naturally ventilated space.