Development of a Standard Testing Method for Vehicle Cabin Air Quality Index

Vehicle cabin air quality depends on various parameters such as number of passengers, fan speed, and vehicle speed. In addition to controlling the temperature inside the vehicle, HVAC control system has evolved to improve cabin air quality as well. However, there is no standard test method to ensure reliable and repeatable comparison among different cars. The current study defined Cabin Air Quality Index (CAQI) and proposed a test method to determine CAQI. CAQI_particles showed dependence on the choice of metrics among particle number (PN), particle surface area (PS), and particle mass (PM). CAQI_particles is less than 1 while CAQI_CO2 is larger than 1. The proposed test method is promising but needs further improvement for smaller coefficient of variations (COVs).