Air circulation vs outside air

[Ryu]

Never saw air coming from the engine compartment. Usually vents right below the windshield. The AC has the capacity to handle it.

My G80 has a Smart Vent to keep you from passing out from your own farts.

Smart ventilation
When driving and the heater and air
conditioning system is off, the smart
ventilation system maintains pleasant
indoor aerial environment by
controlling the temperature, humidity
and CO2 of interior.
"SMART VENTILATION ON" message
is displayed on the AVN climate
monitor for 5 seconds when the
smart ventilation system operates

Also a warning
• Continued climate control
system operation in the recirculated
air position may allow
humidity to increase inside
the vehicle which may fog the
glass and obscure visibility.
• Do not sleep in a vehicle with
the air conditioning or heating
system on. It may cause serious
harm or death due to a
drop in the oxygen level
and/or body temperature.
• Continued climate control system
operation in the recirculated
air position can cause
drowsiness or sleepiness, and
loss of vehicle control. Set the
air intake control to the outside
(fresh) air position as much as
possible while driving.

Thanks for the reply and clarification. Probably correction to my comment that it comes from the engine compartment. The air comes via a plenum adjacent to engine compartment, which is hot. Even though there is insulation it does feel hotter than outside. I appreciate all the smarts with the ac. But that’s all useless when you’re behind an old vehicle exhausting a lot of smoke. Or when your driving through an unpleasant area.
I just want to keep it in permanent reverse cycle and choose to go fresh air when I want.

 

[PMCErnie]

Thanks for the reply and clarification. Probably correction to my comment that it comes from the engine compartment. The air comes via a plenum adjacent to engine compartment, which is hot. Even though there is insulation it does feel hotter than outside. I appreciate all the smarts with the ac. But that’s all useless when you’re behind an old vehicle exhausting a lot of smoke. Or when your driving through an unpleasant area.
I just want to keep it in permanent reverse cycle and choose to go fresh air when I want.

I think this is a case where your car may be wiser than you. You should re-read Ed’s post above, particularly this part.

• Continued climate control system
operation in the recirculated
air position can cause
drowsiness or sleepiness, and
loss of vehicle control. Set the
air intake control to the outside
(fresh) air position as much as
possible while driving.

 

[joegr]

Thanks for the reply and clarification. But isn’t that compartment still hot. The air plenum from inlet to the ac, is next to a heated compartment. There may be insulation around but it’s still collects heat. When driving with outside air fan mode I can feel the warm air coming in, compared to air from the windows. I know it sounds wrong but I’d rather have the ac in reverse cycle and open the windows slight for fresh air when needed.
But do you know how to keep it permanently reverse cycle mode.

Oddly enough, even if you turn the system off, it still heats the air that passes through it as needed to reach the temperature that you have set. Turn it on and adjust the temperature as low as it will go. Now you can turn it off, and it will not heat the incoming air.

 

[Ryu]

Oddly enough, even if you turn the system off, it still heats the air that passes through it as needed to reach the temperature that you have set. Turn it on and adjust the temperature as low as it will go. Now you can turn it off, and it will not heat the incoming air.

Thanks
I can live with the ac temp comfort reasoning. But what about smog or vehicle exhaust from the outside coming in. This is the main reason why I want to keep it in recycle mode.

______________________________

 

[Ryu]

I think this is a case where your car may be wiser than you. You should re-read Ed’s post above, particularly this part.

• Continued climate control system
operation in the recirculated
air position can cause
drowsiness or sleepiness, and
loss of vehicle control. Set the
air intake control to the outside
(fresh) air position as much as
possible while driving.

I accept the reason for comfort control. But the main reason I want to lock it in recycle is to keep the smog and vehicle exhaust from coming in.

 

[joegr]

I accept the reason for comfort control. But the main reason I want to lock it in recycle is to keep the smog and vehicle exhaust from coming in.

Yes, I can understand that, but I don't know of anything you can do about it. It could be worse, GM (at least at one time, if not still) never goes to 100% recycle, they always allow in at least 25% fresh air. I think this is a result of them being sued about some issue that happened when someone left it on recycle all the time.