Q. What is the purpose of the recirculate setting in an automobile?
A. The recirculate button can help your vehicle HVAC system run more efficiently. The setting closes the outside vents and uses only the air that is already inside the vehicle. In cold weather, this prevents constantly introducing cold air into the vehicle, so your system can simply work to keep already warm air heated to temperature. In hot weather, use t he recirculate setting when running the air conditioner to prevent the intake of warm outside air.
Note: While the “recirculate” option may warm the inside of a car more quickly during winter, it also keeps moisture in the air and can fog your windows. It’s better to bring in air from outside the car, which is usually drier, and then switch over to recirculate as the temperature warms.