In the present work, the mathematical modeling of heat transfer in a vehicle’s
cabin is investigated. The vehicle’s cabin temperature is one of the most
important factors in accidents. Thus, it is not surprising that HVAC has a
direct impact on the performance of occupants inside the cabin and especially
the driver. Therefore, it is important to create a good thermal environment to
provide thermal comfort for the driver and passengers. The focus of the current
work is on mathematical modeling and analysis of the comfort conditions of the
cabin. It is already hypothesized in this study that the gas behavior is ideal
and the air properties inside the cabin depend on HVAC module air flow and
controlled/uncontrolled leakage; the air in the cabin is appropriately mixed and
no mechanical work is generated within the control volume. Effective thermal
loads on the vehicle’s cabin are considered, including radiation, ventilation,
ambient air, metabolic state, engine, exhaust, infiltration, and HVAC system,
and changes in the temperature and relative humidity of the air of the cabin
over time is reported, while the HVAC system is operating. Comparing the two
modes of permanent and frequent intermittent infiltration of the ambient air
into the cabin, it is observed that the amount of power consumed by the HVAC
system is increased between 4% to 40% depending on the number of window opening
per hour and infiltration of the air into the cabin. The best and the most
appropriate time-cycle interruption of HVAC system in temperatures ranging from
19 °C to 26 °C in two modes of infiltration and non-filtration of the outdoor
air into the cabin is obtained at 12 s. The position of temperature sensors
inside the cabin is also studied and its effect on temperature uniformity is
compared in three different modes.