Public passenger vehicles in urban environments, which typically have high occupancy rates, require heating, ventilation, and air conditioning (HVAC) systems capable of meeting both air quality and thermal comfort requirements in demanding environments. Moreover, bus cabins and their HVAC systems must be designed to meet different climate types and external environmental conditions, and also be more energy-sustainable. Thus, this study develops a methodology that takes advantage of solar radiation incident on the glazed surfaces of the bus and establishes airflow rates for the ventilation system that ensure the best compromise between air quality and thermal comfort provided to bus passengers.