What's ECON and how is it used properly?

Question

I drive mostly Asian cars which mostly have an air-conditioning interface consisting of a button saying "A/C". This makes sense to me since it's short for "Air Conditioning" (assumption :)). Also the usage is pretty straight forward: you push the button and you gain cold air, release the button and it stops.

However, lately I was driving with my friend's German Car (Audi) and the a-c interface completely confused me. I didn't even find it until my friend helped me out. Apparently you have to deactivate (!) a button saying "ECON". So it's on (a small orange LED indicates "ON") and you have to deactivate (the small orange LED turns off) it in order to activate the air-conditioning.

What does ECON mean? How does this whole concept make sense? Why is it preferable above a common "activate the AC"-button?

Answer 1

It probably has a Climate Control unit which regulates the temperature automatically. This means that the air conditioner should always try to reach the requested temperature. So when it's outside 30 degrees celcius and you request 20 degrees, then your car enables the A/C to reach that temperature. The A/C will stop running, when the temperature is reached, or even heat up the air when it become too cold. This happens when the outside temperature is lower than the inside temperature.

If you enable ECON(Economy) mode, then you disable the air conditioner. The climate control cannot make your car cooler than the outside temperature. So when it's 30 degrees outside and you request 20 degrees, it cannot provide a lower temperature than 30 degrees.

Heating up will not be any problem for conventional car because the car engine is hot enough to warm up the radiator. I don't know how this works on a EV car.

If your car doesn't have a climate control, then you have a manual button to turn the A/C on. This is a dumb system which blows air continuously without checking the current temperature.

Answer 2

From www.reference.com:

The "Econ" or "Eco" button, usually located on the dash, adjusts certain things on the car to improve the automobile's fuel economy. Not all cars have an Econ button, but those that do change in similar ways when the button is depressed.

Essentially, the ECON button is making the vehicle act in a more economic and eco-friendly way. Because the A/C takes power to run, it is dis-activated in the economy mode. So if you want to cool off in economy mode, open a window.

Answer 3

The "econ" button helps you save energy by turning off the AC-compressor and additional* heater.

*On certain Audi models there ought to be an additional heater (powered by fuel) that helps to heat up the passenger compartment quickly on cold-start.

Answer 4

Economy is usually just "fan only" meaning that it disengages the compressor.

The thing that causes the car to use more fuel when the AC is on is the load put on the engine by the compressor (also the draw on the alternator but this is much less than the compressor). The compressor is either engaged our disengaged, it can't be "half-on".

If you understand how AC works you will know that for cold air to come out you need the compressor on.

As an aside, another very common misconception about AC is that higher temp means less power usage and lower temp makes it cooler faster.

The AC unit in a car bows cold air when it's on, it doesn't know what temperature it is, it keeps blowing until shut off. When you turn the temp up in your car, the car either opens a little vent to let hot air mix with the cold air or turns off the AC compressor when it reaches your desired temperature on more advanced vehicles. The same is true for the reverse, the AC unit will blow the same temperature air if it's set for 70 as when it's set for 60, the only difference if how long the compressor will stay on for (making cold air).

So, when you press the ECON button, the fan is just blowing air.

Answer 5

On Asian vehicles (Honda and Toyota) the ECON button decreases the sensitivity on the drive by wire throttle system making it feel a lot tamer. It also adjusts the automatic transmission and the A/C for optimum fuel economy. The A/C still functions but is not as cold as it would be on NON-ECON mode.