Believe it or not, there once was a time when everyone riding in a vehicle had to agree on a single temperature setting. And, of course, this inevitably led to some friction between travelers: Some preferred it cooler while the others rubbed their hands together and claimed to be freezing. Or maybe there was someone in the car who wanted it warmer while others were left sweating and sticking to the vinyl seats. Some compromise might be had by opening a window -- but that often led to other issues with wind and road noise. So what's the solution?
Find a way to let each passenger select his or her own temperature. But really, how practical is that?
Well, if you haven't been new car shopping in a while, you might be surprised to find out that it's actually getting to the point where dual-zone climate control systems are simply passé. (Unless you're looking at a two-seater, in which case, a dual-zone system is perfectly acceptable.) In fact, it's not as uncommon as you might think to find as many as three or even four separate climate zones within the same vehicle.
Each manufacturer has its own distinct method for delivering the perfect climate for individual passengers; however, they all rely on certain similar components, like additional controls in the driver's HVAC (heating, ventilation and air conditioning) control unit, an additional HVAC control unit in the rear seating area, individual temperature sensors for each zone, lots of extra hidden ducting to carry the air where it's needed and extra vents -- lots and lots of extra vents. For example, the Lexus LX570 has 28 of them.
Here's how the BMW 5 Series Sedan handles it. (You'll need to select "More" in the lower left corner of the box to get to the good stuff.) And if you're still not satisfied, here's how the Audi A8 and Audi Q7 electronic climate control system works.
Interesting, huh? Different vehicles and different manufacturers, yet they all seem to have a similar approach.