There was a time when having an AC in your car was a big luxury atleast in our country. We were left at the mercy of the weather to decide whether we could be cool or sweat it out. Almost all of us who own a car (or even if you dont own one) have been around in the good old Padminis and Ambys with our windows rolled down and the quarter glasses open. Those who did go that extra mile to get a retro fitted AC would end up giving their car a hot time.
Time has flown by and the car air conditioner has become a standard fitment on cars sold in the country. There are still a few with a non AC option but that ratio is less compared to the ones with AC. The Indian car buyer has changed over the years. The other goodies can wait but an AC is a must have. With new cars comes new technology and now we have something known as an Automatic Climate Control(ACC) with our car AC. And today if your car doesnt come with ACC, the car buyer blames the manufacturer for being stingy not to offer it. No surprise as one always wants more value for his buck these days.
So what is the difference between a standard car AC and one which comes with Automatic Climate Control? A simple explaination
Standard Car AC:
This is what your standard Car Airconditioner control unit looks like (See Illustration). To use the AC, all you do is turn the Blower Speed Adjust knob and set it to a blower speed of your choice. There is a resistor in the blower switch which helps in setting the various blower speeds. Press the AC Switch to start the AC. In a standard AC you have a temperature knob which you use to maually adjust the temperature you desire in the car (coldest to left and hottest to the right as in the illustration). In short each and every setting is done manually with no inputs from the car whatsoever.
Automatic Climate Control or ACC:
Things are different when it comes to ACC. Here is what a typical ACC layout in a car looks like(see Illustration). You can use the ACC in the following ways:
1. Just press the AUTO. Everything else is taken care of automatically.
OR
2. Press AUTO and set the temperature using the temperature control( you can see the temperature on the display screen). Climate control will maintain this temperature by continually varying the blower speed and temperature.
OR
3. Start your blower using the blower speed switch and press the AC button to start your AC. After that use the temperature control to set the temperature you require in your car at all times. You will see the set temperature on the display screen.
Net net, the main difference between Climate Control and an air-conditioner is the former's ability to continually
& automatically vary cold / hot air + blower speed to maintain the set (and accurate) temperature.
Now how does it work? Once the AUTO button pressed, a module in your car's on board computer comes to life to maintain the set temperature inside the car at all times. This is done by a combination of cold air from the air conditioner and hot air from the heater. Your blower speed is also controlled by a speed controller present in the climate control module. The controller increases or decreases the blower speed automatically. This does away with the regular resistor system leaving you to do the driving.
Nowdays ACC also comes with 'dual zone' or 'four zone' options. In dual zone, the driver and the front passenger can select two different temperature settings which create two different climates in the same car. Four zone takes the split even further by allowing each of the 4 occupants in the car to have different temperature settings (except the middle passenger in the rear seat).