There are two key modes to understand – 'fresh air' mode, and 'recirculation' mode.
Using the Recirculation button helps get your car as cool as possible when it's hot outside and you have the A/C on. It recirculates the kind-of-cool air that you get from the A/C when you first turn it on, and the longer it's on, the cooler you car gets until it's as cool as the system can possibly be.
For Ease of Use: If you prefer a hands-off approach and want consistent comfort, an automatic AC system might be better. For Control and Cost: If you prefer to have more direct control and potentially lower costs, a manual AC system could be the way to go.
You should avoid using the recirculation button in the winter or in cold weather. It traps humidity inside the car, causing foggy windows and mugginess. Instead, use “Fresh Air” mode in the winter. All cold air will be forced through your heater core first so it'll be nice and warm by the time it reaches you.
Choosing a higher A/C temperature will heat the car, go low instead. Choosing the lowest temperature and using your fan properly will make the whole ordeal more cost-efficient.
As a general rule, when it's cold outside make sure the recirculation button is switched off! The air-recirculation button is best to use alongside your AC during warm weather. During cooler weather it doesn't have many benefits and can even be detrimental.
Energy Efficiency
AUTO is significantly more energy efficient between the two modes since the fan is only running when your AC is going through its cooling cycle. This takes less power, which is more budget-friendly, with some estimates showing you can save as much as $50 per month just by keeping your AC on AUTO.
Use Recirculation Mode
Recirculation mode pulls air from inside the car instead of taking in outside air. This is especially helpful if you drive in stop-and-go traffic on a hot day. It does not put as much strain on your system as direct cooling does.
Setting your thermostat to auto will allow your system to be more energy-efficient since the fan only runs when the system cycles on, not continuously. Typically, the fan will turn on 30 to 60 seconds after a heating or cooling cycle starts and then turn off a minute after the cycle ends.
The snowflake button is one of the most crucial to the air conditioning's control. Why? Well, it turns the system on, for starters. Pushing the aircon snowflake ac symbol engages the air conditioning, and kick-starts the a/c pump which draws heat and moisture out of the air before leaving it cooler than it was before.
Cool mode: Ideal for hot days, this mode reduces the room temperature to your desired setting. Dry mode: Perfect for humid conditions, this mode removes excess moisture from the air without significantly reducing the temperature.
Cool mode
This is the most common and usually the default setting when you first turn on the AC. This mode sends cool air throughout your room and is great for cooling down an area after a long, hot day.
There are two key modes to understand – 'fresh air' mode, and 'recirculation' mode. The former is pretty self-explanatory and pulls air from outside the car, but using the latter recirculation mode seals the interior itself off and recirculates the existing cabin air. In older cars, this is controlled by the driver.
If your AC is cold but not cold:
Check to see that the cooling fans on the condenser or radiator are running when the air conditioning is on. Look for any restrictions like leaves, bugs, or dirt that could be preventing air from passing over the condenser. Check the cabin air filter to make sure it's not clogged.
Freon, or coolant, is the chemical in the air conditioning system that cools the air. If the system is leaking, then this chemical will eventually run out. Today's A/C systems are more sensitive than the older ones. The air conditioner will not work properly if there is not enough of this chemical.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
By selecting the Auto feature, the system knows exactly how to reach the desired temperature using the correct blower speed and a more efficient use of the battery, alternator, and ultimately the engine.
Go Low. Setting to the lowest temp and adjusting the fan makes the car air conditioning more efficient, will dry out the air less, and can actually save some fuel. Why is that? In a typical AC system, the air is cooled to 38 degrees.
Some newer models automatically switch modes based on air moisture levels. You should try to avoid using recirculation in the winter, because it can trap humidity in the car, which could in turn fog up your windows.