Outside air vs recirculating inside air

[nomech]

I've noticed that when I have the button to recirculate the air inside the cabin, I can still smell the outside air. I'll add that the defrost isn't on because I know that will cause outside air to enter the vehicle. I bought my 2020 Tahoe brand new, but I suppose that doesn't mean it didn't have an issue with the vent/whatever controls inside vs outside air (possible a damper?).

Has anyone else experienced this or is this something specific to my vehicle?

Thanks.

 

[Joseph Garcia]

I believe that even with the HVAC system set to Recirculate, there is still up to 15% fresh air entering the flow as a safety feature to prevent potential carbon monoxide poisoning, in the event of an exhaust leak.

 

[nomech]

I believe that even with the HVAC system set to Recirculate, there is still up to 15% fresh air entering the flow as a safety feature to prevent potential carbon monoxide poisoning, in the event of an exhaust leak.

That makes sense I've actually read an article stating that if you 'feel tired' while driving, open up the windows and get fresh air in there. That being said, I really wish 15% wasn't being introduced into the cabin because there are times when I'm in traffic and stuck behind a truck with a bad diesel smell, I can't do anything to get it out of the cabin. That's why I thought something was wrong because I looked down and recirc was already 'on' and I could still smell the diesel. Other cars I've been in (all foreign, ironically) I have always been able to click recirc and I never smell outside air.

 

[swathdiver]

I've noticed that when I have the button to recirculate the air inside the cabin, I can still smell the outside air. I'll add that the defrost isn't on because I know that will cause outside air to enter the vehicle. I bought my 2020 Tahoe brand new, but I suppose that doesn't mean it didn't have an issue with the vent/whatever controls inside vs outside air (possible a damper?).

Has anyone else experienced this or is this something specific to my vehicle?

Thanks.

How old is your cabin filter?

 

[nomech]

How old is your cabin filter?

Not old at all, I change it along with the engine air filter regularly. Both were changed last month.

 

[swathdiver]

There can sometimes be an issue where the recirculate or fresh air door doesn't close completely or as the vehicles age, the foam shrinks or falls away and doesn't seal properly anymore letting in outside air.

I'm currently having an issue where my mode door is bleeding in too much outside air when in recirculate mode making the cabin very noisy. System is quiet with fresh air, but smelly from all those poorly maintained vehicles out there!

 

[Doubeleive]

I've noticed that when I have the button to recirculate the air inside the cabin, I can still smell the outside air. I'll add that the defrost isn't on because I know that will cause outside air to enter the vehicle. I bought my 2020 Tahoe brand new, but I suppose that doesn't mean it didn't have an issue with the vent/whatever controls inside vs outside air (possible a damper?).

Has anyone else experienced this or is this something specific to my vehicle?

Thanks.

the only vehicle I know of that will prevent most of the outside air from entering is a tesla.
otherwise air makes it's way in, like it or not. there is nothing you can do about it.
the rear vents in particular are not sealed in any manner whatsoever, they are just slotted to prevent rain from coming inside.
it's also why your ears don't pop from pressure when someone closes a door.

 

[nomech]

the only vehicle I know of that will prevent most of the outside air from entering is a tesla.
otherwise air makes it's way in, like it or not. there is nothing you can do about it.
the rear vents in particular are not sealed in any manner whatsoever, they are just slotted to prevent rain from coming inside.
it's also why your ears don't pop from pressure when someone closes a door.

Thanks for that info. I wish they were like foreign cars. Zero outside smell issues with those vehicles.

 

[Doubeleive]

Thanks for that info. I wish they were like foreign cars. Zero outside smell issues with those vehicles.

all cars will get air inside, otherwise you would hear about dead people sleeping inside, etc, etc
and it's also why many state have guidelines/rules/laws that dictate how long a vehicle can (or should) idle on remote start because idiots park them in the garage and leave it running, which HAS resulted in dead people

 

[mountie]

I've never noticed a difference......