You’re in traffic on a summer afternoon. Sweat trickles down your neck and down your back until the shirt absorbs it, creating moisture between you and the seat. Your legs are glued to the upholstery of the seats, you feel like your hands are about to slip off the steering wheel, and you are grateful that your eyebrows keep sweat from running into your eyes. What is missing from this image? The air-conditioning.
Today we can hardly imagine a car trip without air conditioning. But for half their history, they didn’t. Was only after 1940 Some models began to emerge that were able to control cooling and heating on board and, in fact, it is still possible to find models that, at least in their basic versions, do not have air conditioning. Because when the air conditioning in your car is on and blows out cool, refreshing air, each journey becomes much more enjoyable.
As such, the air conditioner has worked in pretty much the same way throughout its existence: cools and removes moisture from the air. Broadly speaking, there are three main parts of the system: the compressor, the condenser, and the evaporator, plus a few other parts to keep the system running smoothly. But this time we are not going to explain how the equipment works, but we will address one of the issues adjacent to its use: How much fuel does it consume to activate it? Is it the same for everyone?
Air conditioning and heating: How much do they consume in our cars?
The air conditioning and heating in the internal combustion cars they have completely different functions. Although many do not know it, putting the heat on does not increase fuel consumption. The heat is obtained from the energy generated by the motor itself, so it is enough to have it turned on to provide it. That is why, if you turn on the heating, you only need to wait a few minutes to feel its effects (the time it takes for the engine to warm up).
However, we would be lying if we say that its consumption is zero. The fan that passes the heat inside uses electricity from the battery. And to charge the battery it also consumes some gasoline, but very little. So, taking advantage of the heat dissipation of the motor, heating a car is practically free. When driving a gasoline or diesel vehicle, you are wasting every meter that you travel, where the side effect of this is that you can have the heating based on that waste.
Also, the air conditioner uses a compressor connected to the block belt to operate. This also consumes energy and therefore fuel. We talk about between 0.2 liters and 1 liter of gasoline per 100 kilometers (+ 5 – 20%). Obviously, consuming more or less depends on factors such as the outside temperature, the intensity of use of the air conditioning and your own way of driving. Think that the more degrees you need to get on board, the more fuel you need.
But everything changes if we talk about electric cars. As we have seen, a heat engine wastes most of the heat it generates, and in turn it is what promotes heating in an internal combustion car. However, a zero-emission one strives not to waste anything. So if you turn on both the heating and the air conditioning, energy consumption will increase considerably. Therefore, we can say that we are talking about a paradigm shift of the concept.
We have mentioned it above: it is false to say that heating is 100% free. It comes from burning fuel that the car wastes. Getting around in an electric vehicle is “more efficient” in this regard. When the machine is stopped, the energy consumption does too, unless you need the lights, the sound system, the air conditioning or the aforementioned heating. The idea here is that energy consumption is always as low as possible, fighting not to waste anything.
Therefore, if you drive an electric car and need air conditioning or heating, the required energy is drawn directly from the battery, the heart that powers the car in the same way that gasoline and diesel do the same with the combustion engine. That can translate into being able to enjoy the cold and heat emanating from your car’s air conditioner, but at the same time, also you will reduce the autonomy of the vehicle. How much? Under normal conditions, it tends to be around between 10% and 20%.
To avoid reducing autonomy, one of the biggest concerns for customers of vehicles powered entirely by battery packs, many manufacturers are already implementing a small heat pump in their models. This invention with decades of popularity in homes and offices is now carving a niche by plunging into the future of driving, guaranteeing efficiency, performance and benefits whatever the weather conditions to face.
Is it true that power is lost with the air conditioning on?
It depends on the vehicle. To date, it is proven that using air conditioning can cause a significant decrease in the power that the vehicle engine can offer. Estimates indicate that it remains approximately between 2 and 15 hp to the combustion engine, depending on the efficiency of the vehicle’s air conditioning system. This is something that is more appreciated in cars with small engines and little power and torque delivery, while in larger engines it is little noticeable.
However, in modern cars, when the accelerator is fully depressed, the compressor is automatically cut off in order not to put the driver in trouble if he demands all the energy at once. Likewise, all those cars equipped with a Stop / Start system turn off their compressor when the propeller does the same, as long as the latter is not electrically operated. Some power is also lost in today’s zero-emission car, but it is less noticeable than autonomy.