Economy/Recirculate Setting for A/C (190e 2.6) - PeachParts Mercedes-Benz Forum

#1 06-26-2002, 08:25 AM

Hello friends:

I have a quick question regarding the economy/recirculate button that sits directly below the A/C button on the push-button control panel.

When I used to drive GM cars, the A/C had 2 settings --
"MAX" and "Norm". In terms of effiency, MAX was the
best setting -- but I don't really understand why. I think
it was because the A/C system recirculated air that was
already in the car and didn't cool the outside air, which
made the compressor work less.

I'm just curious if this button works the same way as the MAX setting on a GM car. Will the compressor work less if this option is engaged, or is it better to leave it off? How come it only stays on for 30min. at a time?

Thanks very much for your help!

-Michael.

Ali Al-Chalabi · #2 06-26-2002, 09:36 AM

The economy button turns the compressor off.

Recirculate turns itself off after a while because Mercedes does not want you to be breathing the same air for over 30 mins without getting any fresh outside air.

nellotare · #3 06-26-2002, 10:21 PM

Hello All,

I have the original owner's manual for my car and have read all about the Climate Control system, but every time I read it, I discover something new. Mine is a 123 so some things could have changed with other models, but the ONLY way I get recirculated air is with the Temp. Wheel. (also will overide some other settings) None of my buttons have anything to do with recirculating the air in the cabin. When any buttons are engaged I get outside air. Quoting from the manual:

The interior temperature can be adjusted infinitely by turning the temperature selector wheel...

To overide the automatic climate control, turn the temp selector wheel to either MAX OR MIN.

MIN (notched in) = Peak cooling performance, whereby 80% of the air is recirculated and 20% of outside air is introduced. If the blower control is set to "AUTOM", it will run continuously in speed No. 5.

MAX (notched in) = Maximum heating performance. If the blower control is set to "AUTOM", it will run continuously in speed No. 5.

Blower Settings (fan buttons)

Push upper button for maximum air supply (6th blower speed)
Push lower button for minimum air supply (1st blower speed)
Push middle button (spring loaded) for automatic control of air supply within 2nd through 5th blower speed range.

DEFROST button = Always maximum air supply (overiding any other settings of buttons)

OFF = air supply to the interior of the car is shut off (in case of bad odor or automatic car wash)

EC (ECONOMY) = the air conditioning compressor stays off. In any other setting, the AC compressor comes on with ambient temps above +2C/36F. We recommend this setting to be used with cool outside temps so that the AC Compressor stays off in order to save fuel. In the heating mode, warm air will mainly be channeled to the leg room. Only an amount of air sufficient to prevent fog build-up under normal climatic conditions will be channeled to the windshield and the movable nozzles. With cold outside temperatures, the fresh air supply and the blower remain turned off until the engine coolant has wormed up slightly. [this is the setting I use for heat]

NORMAL setting [next button to the left] = same as EC but in addition, the air is being cooled or preheated as necessary [compressor on]

BI-LEVEL [next left button] This setting is necessary for clearing a fogged windshield. As soon as possible reset to EC or NORMAL. In the heating mode [temp wheel in red] air will be channeled to the windshield, the leg room and to the outside movable nozzles. Air will be emitted from the inside movable nozzles at times.

DEFROSTING = Independent of the position of the temp wheel and the blower speed setting, optimally heated air will be channeled to the windshield and the outside movable nozzles.

Important! To ensure proper operation of the automatic climate control system, engage button NORM and BI-LEVEL at least once a month for a short period when the outside timp is above +2C/36F

I got long winded, but hope this helps.

#4 06-26-2002, 10:51 PM

My re-circulate does not work. I can tell because I can still smell the stink %$s with dirty fuel injectors or whatever else is blowing out of their tailpipes, in front of me on the hwy. Any suggestions where to start? Thanx

nellotare · #5 06-26-2002, 11:37 PM

Tank,

If yours is like mine and you're setting your temp wheel to MIN to achieve recirculate, you're still getting 20% outside air and therefore the smell of unwanted odors still persists. The manual say to mash the "0" button when encountering bad odors.. yeah, right, then you just "burn up" inside with no air at all

nellotare · #6 06-26-2002, 11:47 PM

Oh, and HAPPY BIRTHDAY, TANK. at least enjoy the last 13 minutes of it.. sorry I was late in sending wishes.. I'll probably be late with your present also. I placed the order but the Aston Martin people seemed to have misplaced it.

engatwork · #7 06-27-2002, 07:24 AM

moraine - please email me directions on how you got it set up for full recirc or full outside air.
thanks

pentoman · #8 06-27-2002, 07:35 AM

Quote:

Originally posted by nellotare
Oh, and HAPPY BIRTHDAY, TANK. at least enjoy the last 13 minutes of it.. sorry I was late in sending wishes.. I'll probably be late with your present also. I placed the order but the Aston Martin people seemed to have misplaced it.

hahaha

#9 06-27-2002, 08:42 AM

Thanks for the GREAT response Nello! You have a 300e,
right? I think you have more fancy buttons on your
AC/heating system than I do. I have the following:

1. The turn nob which has the notches.

2. 3 buttons
*Dehumidify
*A/C button (that turns it on)
*Economy button

3. I think I only have 4 fan speeds.

I keep hearing all of these horror stories with the A/C compressors on these cars, and it is my thinking that if I engage the compressor less, then it might not die on me!!

Wishful thinking?

I also received MUCH better gas mileage on my GM car when I had the A/C engaged in MAX mode. I really don't use the A/C all that much on the Merc, but it's interesting to see if this helps at all.

BTW: Does anyone have any experience with water pumps? In my other post, someone said that it would be SIX hours of labor to replace the water pump. Then I read other posts that said if you pay more than like $350, you got HOSED! What do you all think??

nellotare · #10 06-27-2002, 12:09 PM

Glad I could help with post from manual. Mine is actually 300D mentioned in signature. Your 190E is different.. perhaps you could find a book that will fully explain your buttons etc. and let us all know. I drove a 190E that I was interested in purchasing (years ago) and the odd thing about the AC to me was that when I pushed the accelerator down to get power quickly, the compressor shut off.. warm air coming from the vents.. when I reached speed and leveled off.. cold air came from vents. I just wondered if this was a way to get more power for the 190E? I wondered if there was an automatic cutoff when you needed power and then reinstated after you achieved your steady speed, or if it was just a quirk of the car I drove. I still don't know the answer, but did like the car a lot.

Oh, and just for the record, when I was 16 and very interested in "wheels", AC was not common on cars. We had to get a car with AC because my father had asthma and AC would be better for him. When reading the book on Buick LeSabre, they said NORM was the most efficient way to run the AC; RECIR was for "in town" driving when air was not being forced into the car from highway speeds. Once achieving steady highway speed, we were to switch to NORM. RECIR was called MAX on some other models of US cars. I have no idea why it was more efficient, just what the book said. Since you get mileage with MAX, maybe the systems have been reconfigured.

tvpierce · #11 06-27-2002, 01:52 PM

Michael,

I have a '92 190E. These controls are a little different than the 300s. Yes, the recirculate button will make your AC work more efficiently, but I'm not sure it will make your compressor run any less. I think the compressor is either on or off depending onthe position of the "AC" button. (By the way, the defrost button -- right above the AC -- also turns the compressor on.)

Jeff Pierce

#12 06-27-2002, 04:38 PM

Can somebody explain when you're supposed to use the dehumidify button? I've never seen a button like this before,
and I can't think of the American equivalent.

Do you use it with the heater or something?? I'm such a dummie!

A. Rosich · #13 06-28-2002, 12:02 PM

The dehumidify buttom is very useful in Tropical climates.

When outside humidity is very high, even with the A/C on your interior car windows will tend to fog (due to the excess humidity).

When this happens, the foggy windows are cleared instantly when you switch on this feature.

Once cleared, you may switch back to the regular A/C setting.

All Mercedes-Benz Recirc modes will allow 20% of outside air (only 80% of the interior air is recirculated). When the evaporator on my E320T failed, I had the system reworked to provide full 100% recirc air instead of just 80%. This does wonders to eliminate outside foul odors while driving. This alteration is very easily done.

In Germany and most markets Mercedes-Benz gave three options for the customers to install in their cars:

1- Only fresh and heated air (no A/C).

2- Regular A/C system with fresh and heated air managment.

3- Automatic A/C.

The U.S. always got the fully automatic A/C system, which, in reality, is less desirerable than the regular A/C system.

The regular A/C allow the driver more control. It provided independent left and right temperature control (for W123/W124/W126 cars). Also, the unit gave less problems in terms of reliability.

A. Rosich
S320, 1998
E320T, 1995

tvpierce · #14 07-02-2002, 11:26 AM

mradowic,

You want to use it whenever there's moisture on the inside of your windshield. For instance, in the winter (and you and I both know winters -- I'm in Maine) moisture from your breath condenses on the windshield. The idea being that since you're trying to remove the moisture (frost), then it works faster if the AC condenser is removing moisture from the air.

Incidentally, in most modern cars, the AC compressor turns on automatically when you direct the air flow to the windshield. (Personally, I hate that "feature" on other cars. Sometimes conditioned air is not needed to keep the windshield clear -- so then the compressor is running unnecessarily.)

Jeff Pierce

#15 07-25-2002, 11:43 AM

Moraine,
Would it be possible that you would share the info on what you did to your a/c? In regards to recirculating cabin air only. It is too hot here in Texas for any outside air.
Thanks,
My email is
jtansey135@earthlink.net

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