With the recirculate button turned on, the air inside the car is recirculated and cooled or heated, rather than being replaced with fresh air from outside. This reduces the amount of energy required to maintain the desired temperature, as the system does not need to cool or heat the incoming air from outside. Additionally, it helps to prevent the build-up of dust, pollen and other pollutants inside the car, which can be especially beneficial for people with allergies or asthma.
Some vehicles also have a "max" setting for the recirculate button, which further increases the efficiency of the climate control system by closing the vents that allow outside air to enter the cabin. This setting can be useful for quickly cooling or warming the cabin, or for maintaining the desired temperature when driving in extreme weather conditions.
It's important to note that the recirculate button should only be used when the vehicle is in motion. When the vehicle is stationary, it's important to turn off the recirculate button and allow fresh air to circulate in order to maintain a healthy level of oxygen and prevent carbon dioxide build-up.
