112263:
What you're describing is the typical manually-controlled automotive A/C system, such as we have in our Corollas. In a Lexus ES300, the A/C is automatic, thermostatically-controlled to maintain a pre-set temperature. If we were willing to pay several hundreds of dollars more for the A/C systems on our Corollas, and if Toyota offered automatic A/C on them in the first place, that problem would disappear. There still remains the issue of the total cooling capacity of a Corolla's A/C system, which, to say the least, is limited to it's present design.
In the Prius, and I assume, other hybrid automobiles, the A/C is all-electric; it's compressor is driven by it's own motor. What I'm wondering is why this paradigm hasn't been adopted sooner, and more universally. It seems pretty obvious that it would solve a lot of problems. For sure, there is going to be an energy trade-off somewhere; the A/C compressor motor requires electrical power, which ultimately comes from the electrical system, which is driven by the engine. Driven by the engine --- how? By an alternator connected to the crankshaft by a belt. Why not a direct-drive alternator, getting it's momentum directly from a driveshaft connected to the crankshaft? It would seem a more mechanically-efficient system than a belt-driven alternator -- and likely more reliable. This direct-drive alternator could even have a two (or more) -speed transmission which could drive the armature at a constant speed regardless of the engine's speed at the time -- including a clutch which could disconnect it altogether when it isn't needed, such as upon start-up when the battery provides the main electrical impetus.
I may be grasping at straws here, but it seems that automotive design is still caught up in ages-old design paradigms that could benefit from some outside-of-the-box thinking.
