air conditioning
air conditioning

The air-conditioning of the car is practically an essential element on hot summer days. The function of this device is to cool the interior of the vehicle to reach a comfortable temperature, but do we know how much it costs and how to save by using it?

Current air conditioning systems are far from those we knew years ago. have been implementing technologies more advanced and precise and now they even allow you to adjust the area to be refreshed. However, the basic process is the same: cool air .

Being able to transform the hot air from outside into a cool breeze entails energy consumption. This translates into a cost of gas in traditional engines and a reduction in the drums in the electric cars and hybrids.

How does car air conditioning work?

This device is nothing more than a cold machine. It uses various mechanical elements and a gas that changes state to cool, filter, and dehumidify the air . Put more simply: it extracts heat from the outside air to bring it cool into the car.

Air conditioning works by mechanical compression of a product that changes from gaseous to liquid and vice versa. This substance is the gas that continuously cools the circuit when you activate the air conditioning in your car.

The process and the elements that this system needs are the following:

  1. On one side is the compressor. It is in charge of sucking in the refrigerant gas and compressing it. When subjected to pressure, it causes its temperature to increase . After this process, the compressed gas reaches the condenser (a coil radiator).
  2. That is where the gas condenses and becomes a liquid . At that moment, it decompresses in the expansion valve and becomes much larger in volume, changes to a gaseous state and cools down again.
  3. The gas, with the temperature already low, passes through the evaporator , which is in contact with the air. Finally, the cold air is propelled thanks to the fan into the passenger compartment through the outlets on the front and side of the car.

This whole process needs Energy. In particular, it is the compressor that bears the greatest consumption. Estimatedly, air conditioning can make your car increase its consumption  between 5% and 20% . This translated into fuel is between 0.5 and 1 liter per 100 km.

It may be that when using the air conditioning you notice how your car has less power. That feeling is real. The air conditioning system subtracts between 2 and 15 HP of power from the engine . This mainly affects smaller cars.

How to use the air conditioning in the car efficiently

With the heat of summer it is logical that we turn on the air conditioning of the car. In fact, it is shown by some brands that high temperatures affect the driver’s reaction . Therefore, it is important to keep the cabin cool and ventilated.

How? Start by frequently checking the equipment of the vehicle. If during the winter months you do not check its status, it may not work when you want to use it in summer.

Workshop checking air conditioning

Keep in mind that the more you have to lower the interior temperature, the more energy the system will need and the more fuel you will use. It is recommended that you open the car doors on both sides so that current is generated and the heat escapes.

Another alternative is to roll down the rear windows slightly for the first few minutes of your journey . This will circulate the air and expel the heat from inside.

Do it only at the beginning of your trip and when you are driving at low speed. The car’s aerodynamics are greatly reduced when driving with the windows down at over 80 km/h . Above activates the air conditioning to save up to 0.3 liters per 100.

watch out for windows

Related to the previous advice, we recommend that you never turn on the air conditioning while you have the windows down or doors open . This will cause the energy consumed by the air conditioning system to be wasted.

just on the move

Also do not use the air conditioning when your car’s engine is off . This will be an unnecessary expense that will not really cool the interior. The system reduces the temperature naturally while you are on the move.

This is because the faster the motor spins, the faster the compressor spins. This allows the system to cool more effectively.

air recirculation

As soon as the interior of your car has reached an optimal temperature, it is best to activate the intake of external air from your air conditioner. This will reduce the energy consumption of the car.

Activate car outside air intake


temperature with head

You do not need to lower the degrees to the minimum. It is better that you maintain a moderate and reasonable temperature for the interior of your vehicle (between 21 and 23 degrees). If you set it, for example, to 19º, this will increase consumption by up to 30%.


Finally, don’t forget to clean the air filter and replace it at the recommended time . As in home air conditioners, it is very important for the air intake.

If the filter is in poor condition, the appliance will need more force (and more energy) to cool the cabin. This translates into higher fuel consumption to reach the same temperature because the air outlet is obstructed by dirt.

Dirty air conditioning filter