A model predicting time required to attain undesired levels of respiratory-CO₂ in closed rooms is described. The model works under the following assumptions: (1) room air is well-mixed, (2) indoor CO₂ does not exchange with outdoor CO₂, (3) there is no effect of individual occupants on CO₂ exhalation rate of other occupants, (4) there is no indoor CO₂ sink and all exhaled CO₂ end up increasing CO₂ concentration in the room, (5) apart from respiration, there is no other source of indoor CO₂, (6) breathing rates of occupants are constant throughout the period of occupation of room. The model makes use of anthropocentric parameters like body weight, height, du bois surface area, MET levels, etc., to calculate dedicated individual CO₂ exhalation rate and uses room volume and number of occupants to predict time required to reach user-earmarked levels of CO₂. A model run showed that in a closed room of 12 × 12 × 10 m³, respiration by one person at rest (65 kg body weight, 1.7 m height, basal respiratory quotient of 0.83) would take 4.37 h to reach 2000 ppmV indoor CO₂ when background indoor CO₂ level was 380 ppmV. This model would help allocating desired number of occupants in closed rooms to help avoid building up of undesirable levels of CO₂ in poorly ventilated offices, schools, hospitals or households that might frequently experience high levels of indoor CO₂, undermining health and performance of occupants, patients and workers.

描述了一个模型，该模型预测在封闭的房间中达到不期望的呼吸CO ₂水平所需的时间。该模型在以下假设下工作：（1）室内空气充分混合；（2）室内CO ₂不与室外CO ₂交换；（3）单个乘员对其他乘员的CO ₂呼出率没有影响，（4）没有室内CO ₂汇，并且所有呼出的CO ₂最终使房间内的CO ₂浓度增加，（5）除呼吸外，没有其他室内CO ₂来源，（6）在整个房间占用期间，乘员的呼吸速率保持恒定。该模型利用诸如体重，身高，杜波西斯表面积，MET水平等人为中心的参数来计算专用的CO ₂呼气率，并利用房间的体积和居住人数来预测达到用户指定水平所需的时间的CO ₂。模型运行显示，在一个封闭的12×12×10 m ^3的房间中，一个人在静息状态下呼吸（65公斤体重，1.7 m身高，基础呼吸商为0.83）将需要4.37 h才能达到2000 ppmV室内CO ₂当背景室内CO ₂水平为380 ppmV。此模型将有助于在封闭的房间中分配所需的乘员数，以帮助避免在通风不良的办公室，学校，医院或可能经常遇到高水平室内CO _2的家庭中积聚不希望的CO ₂水平，从而损害乘员的健康和性能，患者和工人。