Seat heating and ventilation
Description - Seat Ventilation
Seat Ventilation in a W220 S-Class is optionally available in both front seats and as an additional option, in both back seats. The seat ventilation is activated by push button controls on the relevant door panels. Note they are ventilators and not really coolers. It appears M-B research has shown "prolonged use of cooled seats, promotes back pain".
Function - Seat Ventilation
The idea of seat ventilation is to cool the contacted seat area by blowing air over the inside of the seat cushions (directly towards the occupant) thus removing some of the driver or passenger's body heat and reducing the 'sticky' back or behind effect which is common on a hot day. They are particularly useful if you need to wear a suit in the car on a hot day.
The seat ventilation is achieved by means of an electronically controlled fans in the various seat bases and seat back rests. In the W220 there are four fans in each ventilated seat base and six fans in each ventilated seat back rest. (To be confirmed.)
The seat base fans suck internal cabin air from under the seat and blow it over the inside of the base seat cushions (directly towards the occupant). The leather seat covers have small perforations to enhance the air flow cooling effect.
The seat back-rest fans suck internal cabin air through vertical inlet ports in the rear of the seats and blow it over the inside of the back-rest seat cushions (directly towards the occupant). The leather seat covers have small perforations to enhance the air flow cooling effect.
A slight improvement in seat cushion ventilation performance can be obtained by directing air conditioned air to the foot rests so that the seat ventilation fans pickup this cooler air.
Tests - Seat Ventilation
To check if the seat ventilation is working, switch off everything making a noise in the car and listen at each seat while you switch on and off the seat ventilation. The fans can be just heard running if everything is very quiet.
Issues - Seat Ventilation
No Seat Ventilation
W220 commonly experience failed seat ventilation in either one or more base seats and back rests.
A common failure mechanism is for the fan supply wires to break and go open circuit. It is a relatively easy fix to remove and dismantle the seat and repair the broken wire/s.
Poor or Weak Seat Ventilation
The OEM seat ventilation fans look very similar to 1980's style personal computer cooling fans and are rather small and weak looking.
The general opinion is that the seat ventilation is hardly noticeable. This is a typical criticism of the OEM design; "M-B figured out a way to make quad zone climate control and even vents in the B pillar in the back. But they couldn't get the damn vented/ac seats to work well."
Some M-B enthusiasts have replaced the original relatively small fans with larger fans and stated "it's WORTH the damn time, what an awesome mod!", and "I drove around for the last 3 days with this mod, and I LOVE IT. It did make a big difference, now I can feel cooler air through a tee shirt or even through a long sleeve shirt, so much so, that after 15 minutes or so, I have to lower the fan speed to avoid it being too cold. And noise is not an issue even at full speed, as it is drowned with the engine noise and radio."
DIY Fan Replacement - Seat Ventilation
The method involves purchasing slightly larger fans and trimming away as some fan and seat padding material to mimic the form of the original fans and their mounting holes, only in a slightly larger size to suit the replacement fans.
After doing the modification another M-B DIYer stated "it now actually gives purpose to the feature and utility to be able to lower the ventilation settings (before I used high or nothing)".
With acknowledgement to BenzWorld members bobgodd, timeToy, berti_00 et alia for developing a seat ventilation improvement modification and for documenting the steps.
Refer to:
http://mbworld.org/forums/w211-amg/399806-vented-seats-not-so-vented-anymore-3.html
http://mbworld.org/forums/w211-amg/448120-diy-vented-upgraded-seat-fans.html
Part Numbers - Seat Ventilation Fan Replacement
Note the E-Class and S- Class have different seats. The details for an E-Class are provided as a guide only.
For an E55, the stock fan is a Papst, PBT-GF20-FR size is 60x60x10mm. DIYers suggested for higher performance replacements use either 80mm or 92mm fans which are no more than 15mm thick and preferably the Delta EFC0812DB-F00 which is a good replacement.
http://www.cwc-group.com/efc0812dbf00.html
with specification;
- Delta EFC0812DB-F00
- Dimensions: 80x80x15mm
- Voltage: DC 12V
- Current: 0.33A (Max. 0.50A)
- Input Power: 3.96W
- Speed: 3800 RPM
- Air Flow 48.8 CFM
- Noise: 41 dBA
- Bearing: Ball
- Features: PWM, Speed Sensor (Tach)
- Termination: 4-Wire / 12-Inch, (-)Black, (+)Red, (RPM)Blue, (PWM)Yellow
- Datasheet: EFC0812DB-F00 PDF http://site.cwc-group.com/specifications/18408-efc0812dbf00.pdf
- Packaging: Each master box contains 168 pieces, item sold as an individual piece
Note the blue and yellow wires are not used.