Heat Gains from Passenger Vehicles Parked in Residential Attached Garages

This experimental and numerical study investigates the thermal behavior of an attached garage before, during, and after a vehicle is parked within it. Although the characteristics of most indoor spaces are understood and incorporated into modern heating, ventilating, and air-conditioning load and energy programs, as well as in older hand calculations, the transient heat transfer between a recently parked vehicle and its garage, the outdoors, and any attached conditioned spaces has not been incorporated. This paper presents, through an experimental and computational study of an actual garage and vehicle (both common types for North America but explained in detail for those readers not familiar with them), how the garage, vehicle, and house interact. The time-varying heat gain rate from the vehicle is found along with the heat gain to the various surfaces in the garage and to the attached conditioned space. Although finding the heat loss rate from the vehicle and heat gain rate to the conditioned interior were the goals of this research, an unexpectedly large heat transfer path for the vehicle’s heat was found. This study’s results were intended for garages attached to residences, but its observations may be extended, with care, to enclosed garages for larger buildings and those that are freestanding.