Experimental Study on Cabin Carbon Dioxide Concentration in Light Passenger Vehicles †

Abstract

This paper discusses the initial experimental results of monitoring carbon dioxide (CO2) and total volatile organic compounds (TVOC) inside automobiles with different cabin sizes and with different numbers of occupants. The initial study shows that the CO2 and TVOC concentrations are inversely proportional to cabin volume and proportional to passenger numbers and time when the metabolic activities were maintained at the same level. This study was aimed at short distance travel on normal roads, and further studies are to be carried out for long distance running on highways to make sound decisions on automatic air inflow control to maintain the in-cabin air within permissible levels of CO2. The study shows that a CO2 concentration of 1500 ppm is reached by all three light passenger vehicle types used within 20 minutes with a single person and reached a CO2 level of nearly 3000 ppm within the same time with two passengers in the cabin.