Soulfly21

I have a 93 300zx. I prefer not to use the climate control when possible. I have noticed if I set the temperature to high It will open the vents to the heat when I believe activates the heater core, it blows warm.

When I set it low I am not sure if it does the same and power the ac condenser, but I do feel air through the vents, cool air. I dont know if its from the ac because I have no Freon.

Basically heres what I would like to know-
Does the climate control still power up the ac/heat even in the off mode?
If I set the temperature to the middle will it disable them?

Thanx Guys!