Qi M W, Li X F, Weschler L B, Sundell J
Department of Building Science, School of Architecture, Tsinghua University, Beijing, China.
Indoor Air. 2014 Dec;24(6):559-66. doi: 10.1111/ina.12110. Epub 2014 Apr 17.
Carbon dioxide (CO2 ) metabolically produced by humans has been widely used as a tracer gas for determining ventilation rates in occupied rooms. Among other necessities, the method requires good estimates of human CO2 generation rates. An empirically derived equation is widely used to calculate the CO2 generation rate. However, there are indications that this equation is not valid for young Chinese people. In this study, we measured the CO2 generation rate of 44 young Chinese people at two typical activity levels, quiet sitting and relaxed standing. We found that the commonly used empirical equation overpredicted CO2 generation rates, but could be corrected with a factor of 0.75 for Chinese females and of 0.85 for Chinese males. The variance for measured CO2 sitting was much smaller than for standing, and hence, we concluded that sitting yields more precise CO2 generation estimates. The relative contributions of sex, height, weight, and metabolic rate were analyzed. We concluded that the error in estimating metabolic rate is responsible for most of the difference in measured generation of CO2 from the empirical equation's predictions.
The tracer gas method using CO2 generated by people is widely used to calculate ventilation rate. However, the empirically derived equation that is normally used to estimate CO2 generation rate is not suitable for young Chinese people at rest. To estimate the CO2 generation rate in Chinese people under low-activity conditions, the empirical equation should be multiplied by correction factors of 0.75 and 0.85 for females and males, respectively.
人体代谢产生的二氧化碳（CO₂）已被广泛用作示踪气体，用于测定有人居住房间的通风率。该方法的其他必要条件之一是需要对人体二氧化碳产生率有良好的估计。一个根据经验得出的方程被广泛用于计算二氧化碳产生率。然而，有迹象表明该方程对中国年轻人不适用。在本研究中，我们测量了44名中国年轻人在安静坐着和放松站立这两种典型活动水平下的二氧化碳产生率。我们发现，常用的经验方程高估了二氧化碳产生率，但对于中国女性可乘以0.75的系数、对于中国男性可乘以0.85的系数进行校正。测量得到的坐着时的二氧化碳产生率方差远小于站立时的，因此，我们得出结论，坐着时能得出更精确的二氧化碳产生率估计值。分析了性别、身高、体重和代谢率的相对贡献。我们得出结论，代谢率估计误差是实测二氧化碳产生量与经验方程预测值之间差异的主要原因。
利用人体产生的二氧化碳的示踪气体方法被广泛用于计算通风率。然而，通常用于估计二氧化碳产生率的经验方程不适用于休息状态下的中国年轻人。为了估计低活动条件下中国人的二氧化碳产生率，对于女性和男性，经验方程应分别乘以0.75和0.85的校正系数。
