BruNo

I have a Thermotronic (digital a/c) --> known as climatronic in the U.S., since day one, ive observed that this A/C allows outside odors to enter d cabin unless i switch ON the Charcoal filter and switch to air recirculation.

Is this a/c really like this???

Especially wen following "smoke belching diesels" this climatronic a/c simply blows cool diesel fumes to my face...hehe

tifosiv122

I leave my charcoal filter button on, but as far as I understand it won't do much in a car that it didn't come with it from the factory.

Erik

Matt230K

Bruno, yes, the charcoal filter is designed to remove these smells from the air. So you should turn it on when you get behind the big diesel truck. You can leave it on if you always have bad smells where you drive, but it does cause the air flow to be a bit less. You should be able to remove the smells with putting it on recirc though.

BruNo

i have factory Thermotronic coz ive got a euro version C240. so this means, its "normal" for d car to allow smell to enter....the charcoal filter does filter...but it "restricts much" of the air coming out of d vents. and its so hot in here!!!!!!!!!!!!

my previous benz didnt have auto climate control..but it did a good job of filtering odors even with "fresh air mode". and it didnt even have charcoal filter.

tberry

Bruno i think what you would like it to do is like in the newer BMWs. I read that (and dunno from what year starting) they detect "pollution" meaning I think smoke and somehow just bad smell in general and will start automatically go into recirculation mode (if u leave on auto). It has some kinda bad smell sensor dunno how to describe it better. I think (hope) maybe its incorporated into other MB models (E, S class?). Although I really do enjoy my EC/REST mode when leaving the car for a few minutes.

JAM

Anyone know the european part number for DIGITAL thermotronic / climatronic that they use for the EUROPEAN C240?

MarkL

Most cars don't have a charcoal filtration system, and typically, the recirculate mode is used to prevent outside air from entering the cabin. Other than having the air intakes somehow pointing away from other vehicles in front of you, I'm not sure how any automotive HVAC system could "filter" unpleasant odors from vehicles you're following.

MB-BOB

A/C in normal mode is designed to let in outside air, like any other A/C system. Punch the recirculation button to limit the amount of external air entering the cabin when you're behind the smelly truck. I never think to use the charcoal filter.

avlis

Interestingly, I have noticed more odors entering my C than I have with previous cars. I have no idea why this would be the case, afaik, most cars suck air in from the cowl in front of the windshield.

I was going 75-80mph a few car lengths behind a guy smoking a pipe and we could smell it in my car! I always get cigarette smoke from cars in front of me.

An inside joke between the wife and I whenever some smoky smell enters the car, "Is my friggin car on fire again?!" (usually followed by uncontrollable laughter) . A reference to the time when I left the oil filler cap off and burned a quart of Mobil 1 on our way to work.

revstriker

I normally just use the filter. It works pretty good, but as others have pointed out, it does restrict the flow of air somewhat. If I know I'm going to be in heavy traffic, then I will just select the recirculate button.

I haven't noticed smells getting into my car at a greater rate or frequency than any other car I've ever owned.

mrkrichie

For some reason, MB will let in the smell a lot more than Japanese cars.
Dunno why.

pokerFACE

hmm I thought auto HVAC (the digital climate control) has an automatic smog sensor? or is that only on higher-end MB's? I know my dad's 97 E320 has it... it will use the filter or go into recirc mode automatically when pollutants are detected..

may not do much for smells though (ie.,skunk) I mean, the filter may get rid of the smell, but the sensor may not detect it.

ffejalink

Is it possible to add the charcoal filter to the non-digital climate controls? After all, it is just a filter.

JAM

From what I understand, and from exploring my S320 and E320, the charcoal filter is located in a system of ducts that are engaged with routing flaps. so adding it in may be difiult, unless you just stick it in-line and have it on all the time. The problem with having it on all the time, is that it restricts air flow, so you always need to run a higher (noisier) fan speed.

ffejalink

Oh well. That's not really the important filter anyway. Thank goodness these cars have a pollen/dust filter. Going without drives my allergies through the roof!