On Sun, 2 Jun 2019 06:43:41 -0700 (PDT), trader_4
wrote:

On Saturday, June 1, 2019 at 4:04:31 PM UTC-4, Thomas wrote:
I have 3 choices on my window ac. Close/Fresh Air/Vent What are the differeces? I smoke and want to be cool but ...fill it in

My guess would be:

Close - no interaction with outside air
Fresh - draws in some outside air
Vent - pushes out some inside air

Yup, same as your car.
Closed is looping inside air through the evaporator with ther AC on
(fastest cool down)
Fresh is pulling air from outside through the evaporator with the AC
on (AC has to work harder to keep it cool but you are turning over
the air)
Vent is just that, fresh air is pulled in but the AC is off so there
is no cooling., It is just a fan.