Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

i was just wondering if our cars have a recirculation cabin air filter. i know we have a pollen filter to check the air going into the cabin from the outside. what happens if we always have the ac set at recirculation mode? does the air still pass through the same pollen filter located in the front trunk near the wiper beffore it goes to the evaporator? i have an s class that has a filter inside the cabin that filters the ac air in recirculation mode and it gets dirty fast. Im just thinking if the air in recirculation mode goes straight from inside the cabin to the evaporator, the evap will get dirty fast... seems very unlikely for a $100,000 car

Share this post


Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

i was just wondering if our cars have a recirculation cabin air filter. i know we have a pollen filter to check the air going into the cabin from the outside. what happens if we always have the ac set at recirculation mode? does the air still pass through the same pollen filter located in the front trunk near the wiper beffore it goes to the evaporator? i have an s class that has a filter inside the cabin that filters the ac air in recirculation mode and it gets dirty fast. Im just thinking if the air in recirculation mode goes straight from inside the cabin to the evaporator, the evap will get dirty fast... seems very unlikely for a $100,000 car

Item 2 is your pollen filter. It does the same process as the Mercedes filter.

post-1-0-85077900-1289159055_thumb.jpg

Share this post


Link to post
Share on other sites

hi loren, great to hear from you. thanks for indicating that however i wonder how the air in recirculation mode gets filtered before enterring the evap? from the diagram i can see that the pollen filter cleans air coming from the outside - recirculation mode is off. Does it also clean the air in Recirc mode? merc has 3 seperate filters - one for outside air(similar to item 3 in diagram provided) - recirc off, one for inside air-recirc mode on, and one charcoal filter for removing smell from air coming from either source...

from the way it looks on the diagram, the item 2 is exposed to the outside air and is used only when air from the outside is brought in to cabin

Share this post


Link to post
Share on other sites

I doubt that the polen filter is in the loop when recirculation is engaged. What's the point of constantly filtering, internal (supposedly clean) air anyway? In addition, recirculation should be used as least as possible.

Share this post


Link to post
Share on other sites

The pollen filter is only for outside air because the flap under the filter is closed when REC. is engaged. Anyway, the filter should be replaced on the regular maintenance schedule because he always is exposed to the outside air, independent of the AC/HEATER/VENT. system actual position. I would further follow up ADias counsel concerns the REC. position.

Share this post


Link to post
Share on other sites

major reason why recirculation is almost always on here where i am is the pollution in the streets. if recirc is not activated all the smoke and the smell will go in the car. now the supposedly clean air inside the car is not the case again where i am. As i have pointed out my S Merc has a recirculation filter inside the cabin. this one gets dirty quite fast i should say. i clean it more than 3 times a year. If we all agree that there is no filter for recirculated air can someone point out to me where the system sucks in the air in recirculation mode? i would like to adapt a filter there similar to the filter used for window type airconditioners used in the house. 3M filtrete would me my filter medium. hope someone can point me to the right direction. just a preventive measure to lenghten service life of my evaporator.

Share this post


Link to post
Share on other sites

Slicky Rick: In recirc mode there is no overt air input. You are breathing closed cabin air. Of course, there's always some air creeping in from the outside, but less than when recirc is off.

The pollen filter, stops large particulates but not gases or smells.

Your S-Merc cabin fllter does not renew the air, just cleans it from particulates. Are you sure that that filter is not used by external air. The fact that the filter is inside the cabin does not mean that it is strictly used in recirc mode.

Share this post


Link to post
Share on other sites

hi adias, yes pretty sure that the filter cleans air being sucked by the system from inside the cabin in recirc mode. the filter in my mb is located below the dash in the passenger side footwell. it is very easy to clean and you can hear and feel the air being sucked in by the ac system from this area when in recirc mode. the outside pollen filter is located in an area similar to our p-cars, inside hte engine compartment. when recirc is off you can hear air being sucked in from the external filter, when recirc is on a valve is closed and air being introduced to the system comes from the passenger footwell area i mentioned. I am pretty sure the system in our p cars are similar. recirc mode sucks in air coming from inside the cabin and it closes a flap that leads to the polen filter we all know is located in the engine compartment.

i can only imagine how fast my evap would get dirty if there was no filter in recirc mode. it will be like the system in my 80's old cars where the evap input is simply exposed to the air inside cabin and pushed through the evap for cooling..

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.