[Isaac Zachary]

So I was thinking of a few things. 1. It's more efficient to heat/cool your body directly. 2. Engines are less efficient when cold but heaters take away heat from the engine. And 3. If I were to limit when my car can heat the cabin, why not limit the A/C while I'm at it?

So here's the specifics:

Idea #1:
Hook up a heat exchanger (air to water) right after the heater core and A/C evaporator. Run that to small plastic lines in the seat(s) that I'd have to take apart and put back together. Hook up a pump that turns on anytime the heating/airconditioning fan is on.

How it works:
The heater or A/C will be heating or cooling the air it's blowing into the cabin. Part of that heat or coolness will be assorbed into the heat exchanger and pumped into the seat(s) which would more effectively heat or cool the driver's (and passengers') body(s) directly. This would make it so that people would tend to use less heat and cooling.

Potential problem:
If you need to defrost the windshield and alrady feel pretty warm well now you're forced to sit in a hot seat. Of course simply installing a switch would solve the problem.

Idea #2:
Add a heater control valve that does not open up until the engine reaches a certain temperature. It can be made so that it also closes if it falls back under that temperature.

How it works:
In order to warm up the engine more quickly this would force the driver to not use the heater until the engine is warmed up. This would also help hybrids by keeping the engine temperature above the threshold that causes them to start the engine again to keep it warm.

Problems:
Well, no heat of course, at least at first, especially if you don't drive very fast. It might make you want to idle your car to get it warmed up before driving instead of getting in and going. (Unless you add a forced start/stop system that keeps the engine off if you're not going anywhere).

Idea #3:
Add sensors that limit (turn off) the A/C compressor when you aren't driving efficiently for A/C use.

How it works:
For an example, in a hybrid the engine will start and begin charging the HV battery if you use the A/C a lot while stopped. By adding a way that it automatically shuts off the A/C when the HV battery reaches a certain point then it won't go so low that the engine is having to start again and again.

In a conventional vehicle you could set other parameters. For an example, that the A/C only turns on after a certain speed.

Problems:
Well obviously you'd fry yourself from the heat anytime you're stuck in traffic.