Does your dual zone climate control over compensate for sunlight?

[Ryan_R]

The only vent I turn away from me is the one on the right - otherwise my right hand on the wheel slowly starts to freeze

[Brendan_A]

Yep, exactly. I never have the vents facing on me. Not in the office, home, nor car.

You wait to you get your Golf R, then you'll know what we are all talking about.

[prise]

I logged data on the drive home today for various air temperatures and sun intensities measured by the climatronic unit including the air-con compressor torque (temperatures plotted here).

http://dl.dropbox.com/u/14542234/LOG...11-581-601.pdf

The set temperature was 23 deg on both channels and the measured cabin temp was relatively stable, sitting between 24 and 26 degrees with the air temperature coming out of the front vents varying between 6 and 26 degrees. It is was interesting to learn that the cabin temp is measured using an infra-red detector, so it is measuring the temperature of the interior surfaces rather than the air temperature which is an important difference to many other HVAC systems (I've run a quick experiment on the sensor which is visible on the front panel of the climatronic system and it appears to be sensitive to both cabin air and surface temperature). The system very active with constant adjustments and the air temp from both the front and foot vents differed by up to 10 degrees right to left.

I've decided the best position for the front vents is up and away from me, given they can push out 6deg air at short notice!.

[cameronp]

• On hot days, I need to set the control to 25 degrees so it doesn't continue to blast cold air in my face. Vice versa on cold days.
• When entering a very hot cabin, it is far too conservative in blasting the cabin with cold air. The fan is never set to maximum, so I do it manually.
• If the unit is set to Off, then nothing should come out of the vent. I always get the climate du jour filtering through the vents when I do this. But I can't close the vent with the unit off.

Amusingly, one of my complaints is the opposite of yours: I often find that the fan speed is a couple of clicks faster than I'd prefer when I first get into the car on a warm day.

Allowing some amount of outside air into the cabin when the fan's switched off is how every car I've ever owned has behaved, and it seems quite odd that you'd want anything else. I do find that I've had the temperature set slightly lower in winter than in summer, but mainly that's due to often wearing a jumper and possibly a jacket as well when it's cold outside.

Actually... facing the vents away from your face/body may solve alot of the A/C problems people are facing (pardon the pun).
You dont usually sit in a room or office with the A/C blowing on you. The air coming out of the car vents is WAY colder than that temp set on the dial. Mix that with the wind chill of moving air then I can understand why some people could find the climate control erratic. Its trying to cool the entire cabin, not just the person the air is blowing on.

That makes a lot of sense, I'm going to try that next time I drive. On the other hand, on a hot summer's day I usually prefer to have 'as cold as possible' air blowing directly on me, because no car aircon can maintain a sensible cabin temperature with 40-plus-degree sun pelting down.

[prise]

For those that want to experiment, I've located the sensors in the cabin and found descriptions for them in a couple of VW Self Study Programmes.

The 'unventilated interior temperature sensor' is integral with the Climatronic control panel and is the small protuberance located in the middle of the shiny black strip underneath the top row of buttons. It measures surface temperature, unit temperature and sunlight penetration (Ref SSP-318, pg 69).

The 'sunlight penetration photosensor' is flush with the top of the dash and sits between the RH and LH windscreen defrost vents. It measures the intensity and direction of sunlight penetration (Ref SSP-271, pg 59).

[PassatB6]

Calling the air conditioning unit in the Golf "climate control" is optimistic at best. Extreme temperatures variations aside, we should be able to set the control to a comfortable level and have it self-adjust. Here are some of the problems I have:

• On hot days, I need to set the control to 25 degrees so it doesn't continue to blast cold air in my face. Vice versa on cold days.

No, the car is supposed to put out cold air on hot days and hot air on cold days. If you don't want to be blasted in the face with hot or cold air, you need to point the vents in another direction.

[GTICam]

For those that want to experiment, I've located the sensors in the cabin and found descriptions for them in a couple of VW Self Study Programmes.

The 'unventilated interior temperature sensor' is integral with the Climatronic control panel and is the small protuberance located in the middle of the shiny black strip underneath the top row of buttons. It measures surface temperature, unit temperature and sunlight penetration (Ref SSP-318, pg 69).

The 'sunlight penetration photosensor' is flush with the top of the dash and sits between the RH and LH windscreen defrost vents. It measures the intensity and direction of sunlight penetration (Ref SSP-271, pg 59).

Hi Prise,

Thanks very much for that. I think the sunlight penetration sensor might be a little too sensitive in some cases. Will try some experiementing with the sensors in my car to see if it affects the aircon response.

Which self study guide did you get the info from? Can you provide a link please?

Thanks again.
Cheers,
Cam.

[prise]

The Mk 6 Golf SSP's arent out in the public domain but fortunately the system design has been re-used from the Mk 5 and many of the components have been used previously.

Here's where you can find the guides I referenced. VolksPage.Net - Technik - SSP - Self Study Program VAG

VW's erwin site will have the Mk 6 self study program material if you're prepared to pay the access fee.

[Corey_R]

Does erWin definitely have self study material? I know it has the service manuals, but I haven't seen the self study materials there.
But having said that, I've only paid to use the site for 1 hour previously

[prise]

yes it does - they've got all the numbers up to SSP 446. It's under training items.