AC on and windows /sunroof open

John Laidlaw

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as title- anyone on here run their climate control or AC at the same time as having the windows/Sunroof/Panoramic roof open?
I did with the SL in the winter but that was hot climate setting to get the body toasty on sunny days whilst still getting the roof down...
Debate:
 

daveenty

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My A/C is always on with the windows and roof closed.

The only exception is if the car's been parked in the sun for a while and it's like an oven inside it. I then set off with the lot open, closing things as soon as it's cooled down a bit.
 

sl500amgsport

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as title- anyone on here run their climate control or AC at the same time as having the windows/Sunroof/Panoramic roof open?
I did with the SL in the winter but that was hot climate setting to get the body toasty on sunny days whilst still getting the roof down...
Debate:
I ran this question a few weeks ago, the overall consensus was turn a/c off when roof down as it cannot cool the interior against the heat outside, a few said they still use it for cold air on the face, aircon technician said it is not very "green" to run it as it will use extra fuel and not be useful....

Mercedes SL500 R231
 
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John Laidlaw

John Laidlaw

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I ran this question a few weeks ago, the overall consensus was turn a/c off when roof down as it cannot cool the interior against the heat outside, a few said they still use it for cold air on the face, aircon technician said it is not very "green" to run it as it will use extra fuel and not be useful....

Mercedes SL500 R231
Oops missed that sorry! (I’m usually more observant honest)....
 

Wighty

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I run ac all year in the Clk , normally turning it off when the roof us down . On occasion in France we have had the aircon on but directed into the footwells when the temp is in the high 30's because I can't think when my feet are on fire :D
 

Gkinghorn

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I leave mine on but it noticeably reduces the air speed and I’m sure doesn’t actually cool much as soon as the top goes down ... I could be wrong but I’m pretty sure ..


Sent from my iPad using Tapatalk
 

Craiglxviii

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Oops missed that sorry! (I’m usually more observant honest)....
The fuel efficiency debate of AC in a 5.0 V8 doesn’t really concern me... sometimes I have windows down (ahhh, no B pillar, ahhh) and sometimes up. Depends on the weather really, it’s been so damn muggy of late.
 
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John Laidlaw

John Laidlaw

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The fuel efficiency debate of AC in a 5.0 V8 doesn’t really concern me... sometimes I have windows down (ahhh, no B pillar, ahhh) and sometimes up. Depends on the weather really, it’s been so damn muggy of late.
Exactly right Craig wasn’t the fuel efficiency worried me either...
 

sl500amgsport

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I was concerned running it with roof down might wear it out prematurely due to being overworked or require earlier top ups with refrigerant but was told that wasn't the case. I tend to pamper my cars though!

Mercedes SL500 R231
 

LostKiwi

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I leave mine on but it noticeably reduces the air speed and I’m sure doesn’t actually cool much as soon as the top goes down ... I could be wrong but I’m pretty sure ..


Sent from my iPad using Tapatalk
Pretty sure that's what I'm seeing too. We never turn A/C off in the SL. It does create a nice cool bubble of air if you use the windows up and wind deflector up (which we do on motorways).
 

Craiglxviii

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Just remember, turning the AC off on an MB doesn’t turn the compressor off. It just closes the cold air valve into the ducting.
 
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John Laidlaw

John Laidlaw

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So it’s better just to keep it on regardless I think. The only thing that you’d lose is the noise if you switch it off
 

Botus

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My A/C is off in this extended run of hot sunny weather (two weeks and counting)...my windows are open.


that'll cause an irreparable gas leak on the compressor on old cars, maybe variable rate ones cope. but even so if you don't drive the car every week for regular periods over 5 to 7 years, all the gas will be on the outside
 
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Naraic

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that'll cause an irreparable gas leak on the compressor on old cars, maybe variable rate ones cope. but even so if you don't drive the car every week for regular periods over 5 to 7 years, all the gas will be on the outside
Don't worry, I drive the car every day, and when the sun doesn't shine the climate control is on. I just don't believe in trying to cool all of Belfast with the windows open.
 

LostKiwi

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Don't worry, I drive the car every day, and when the sun doesn't shine the climate control is on. I just don't believe in trying to cool all of Belfast with the windows open.
I view it as doing my bit to combat global warming (;))
 

RUBBER_UNDIES

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as title- anyone on here run their climate control or AC at the same time as having the windows/Sunroof/Panoramic roof open?
I did with the SL in the winter but that was hot climate setting to get the body toasty on sunny days whilst still getting the roof down...
Debate:
A/C is most effective with everything closed.

Think of how your fridge works at home.
 

RUBBER_UNDIES

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Air con stops your windows from steaming up.

There's no moisture in air con.

And turn your recirculation off.
 

Argus

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My A/C is switched on all the time, probably because I forget to switch it off when the windows/roof is open. However, in the recent past I have experimented with switching it off for a week at a time and checking the fuel consumption (I drive approx. 1k miles per week). Ive not noticed any appreciable difference in mpg.
Maybe it's more noticeable in smaller engine cars? (mine is 3L)
 


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