How is air conditioning powered in cars? Is it by the battery or by petrol? Or is it neither?

Question

I have a Peugeot 206.

Answer 1

The aircon compressor (the component that chills the air) is driven by a belt from the engine. The harder the compressor has to work, i.e. the more cooling required, the greater the additional load on the engine.

Estimates vary but expect aircon to add up to 10% to your fuel bill depending on the size of car and the ambient temperature.

Driving with windows open does add to fuel consumption too because of the additional drag created - the effect's greater at higher speeds.

To reduce the effect of aircon on fuel consumption
- open windows, sunroof etc. to let hot air out of a parked car before using the aircon
- turn the aircon off and open windows around town when driving slower
- use aircon only when required rather than leaving it on whatever the weather/temperature
- use it from time to time all through the year
-Get it serviced every 30,000 miles or so, and
- make sure that windows and the sunroof are closed when the aircon is running

Answer 2

It is powered by the petrol or the diesel - the fuel - on which the vehicle runs.

The battery will play a large part in many of the vehicle's operations but never forget, it is just a space where you can STORE some energy for a while and this store needs to be constantly replenished - using fuel.

The alternator delivers energy to the battery when its sensors detect a need for it. This means that MORE FUEL will be used to drive the alternator when it has such need - load.

(You can demonstrate this for yourself: Start your engine and let it idle, then switch on all your main headlights and your heated rear screen - and, importantly, here - your air conditioning! You will hear an unmistakable drop in the engine's "revs" as it takes on the task - the new load - of supplying all these circuits via the alternator (the electricity generator) Try it!

Air conditioning systems are just refrigerators that cool the interior of the vehicle by pumping HEAT (not air) from the inside to the outside (Note: really silly therefore to run them with your windows open!)

They are 'heat pumps'. Just like your domestic refrigerator.

They don't remove hot air. They remove HEAT FROM the air.

This takes lots of energy and heat pumps are more efficient, the better the insulation - which prevents the 'ambient' (outside) heat from returning.

As most vehicles (all vehicles, really, with the exception of Nordic motorhomes designed for very cold climates) have very poor insulation, outside heat is always finding its way back in. Also, people keep opening doors and windows - which has the same effect! New hot air comes in! So the air conditioning needs to keep pumping it's heat energy back out again!

Thus using much more petrol or diesel etc. (fuel) for the purpose.

(Don't forget: anything in the battery - and that is actually a really large amount of energy - was, nevertheless, put there by the alternator (generator) which is driven by the engine - on fuel!) It is just a very big store of energy. But it is supplied from fuel.

Hope this explains - it is a very good question and one that people should understand if they are to avoid lots of unnecessary problems and expenses.

Close all the windows if your A/C is on! (Otherwise, it's just like leaving your 'fridge door wide open!)

Stay cool, sister!

Answer 3

The air con is usually run by pump which is belt driven off of one of the pulleys where your alternater is ( cam belt side of engine) this circulates a refridgerant round a circuit, like a radiator on a car, then the air that is cooled over this radiator is pumped in to the car, this puts an extra srtain on the engine and battery as the engine will rev slightly higher to make the alternator work faster to keeep up with voltage demand, thus using more fuel, i hope ythis answers the question.

Answer 4

The aircon of a car works the same as a domestic aircon,the only difference is that the compressor is driven by the engine and the fan by the battery which is kept charged by the alternator which is also driven by the engine.
Car aircons use around 8-10 horsepower so your fuel consumption will increase by 3-5 mpg.
To cool the same volume a cars aircon has a larger cooling capacity than a domestic one because of the poor thermal insulation of a car

Answer 5

Using the heater will in theory cause a tiny amount of extra fuel consumption, due the the power used to drive the ventilation fan. it is so tiny as to be unmeasurable and is certainly never worth worrying about. Aircon on the other hand does cause a noticeable increase in fuel consumption, due to the power needed to drive the compressor. It can be as much as 10% in extreme cases. Over about 30mph it is more economical to use aircon and keep the windows up, due to the extra drag with open windows. Below about 30 mph it is usually cheaper to turn the aircon off and open a window. Either way it is far better for the driver to be comfortable and able to see clearly than to worry about a few pennies.

Answer 6

Car air conditioning is powered by the engine (fuel) of the car which powers the compressor of the coolant. The pull of the coolant in the evaporator by the action of the compressor causes the evaporator grill to chill. A fan powered by the battery then blows air through the cool grill to sooth you. Thus you wont be wrong to say it is powered by both battery and petrol.

Answer 7

All electronics in a car are powered by the battery, however this is in turn charge by the action of the motor, which is burning fuel.
Every electrical item that you ahve running will cause the engine to speed up to meet the power requirement, meaning more fuel is burned.

Air con is very energy-zapping, and therefore burns fuel much quicker than some other things.

Answer 8

The main component that requires power to run the air conditioning is the compressor. This is powered from the engine via a drive belt. This is the reason why fuel economy increases when you turn the air con off.

Answer 9

The aircon pump is driven by the engine. When you switch the aircon on, the pump is put "on load", so its extra drag means more fuel consumption. Aircon doesn't work without the engine running. The circulating fan is electrically driven.

Research as shown that below about 30mph it's more economical to have the windows open, above approximately that speed the drag from the windows means it's better to close them & turn the aircon on instead.

Answer 10

Your standard auto A/C works by a compressor that's powered off a drivebelt linked to your car's engine (which is run by petrol). The blower fan, which distributes the cool air inside, runs off electricity, generated by the alternator, stored in the battery.
So, both, is the right answer.