Air con with the roof down 🤔

[omegabri]

Evening all

Just curious......What's the official say-so on leaving the air conditioning on in the car if the roof is down?
It can get pretty warm in the car on a good run, especially with the roof down in hot sun (not that we get that too often in the UK! )
I was wondering if it might damage the air con unit in any way? I've inadvertently left mine on a couple of times, then noticed how fresh it still is before turning it off. I'm not bothered in the slightest about fuel efficiency, but don't want to put adverse stress on the air con unit, or car battery etc..

Curious if anyone knows the official, or indeed if anyone else leaves the climate/air con on regardless

Cheers everyone
Bri

 

[B21]

Don’t know on G29 but the E89 was designed with air con being used roof down…in fact there’s data sent to the unit to tell it the roof’s down..

 

[omegabri]

Don’t know on G29 but the E89 was designed with air con being used roof down…in fact there’s data sent to the unit to tell it the roof’s down..

Interesting

 

[Pondy]

Don’t know on G29 but the E89 was designed with air con being used roof down…

Utter bollox (again). No car was 'designed' in that way.
A/C is just a mechanical cooling system. I could explain how it works, but you probably know more about that than me already, so I won't.

 

[Pondy]

I was wondering if it might damage the air con unit in any way?

Nope. It will just use more fuel for no gain whatsoever.
You could argue it actually helps, as if the A/C isn't used periodically it WILL leak refrigerant over time.

 

[Zedebee]

I was wondering if it might damage the air con unit in any way?

Nope. It will just use more fuel for no gain whatsoever.

Eh? It will still blow cold air through the vents, which is what you want on a hot day

 

[Pondy]

I was wondering if it might damage the air con unit in any way?

Nope. It will just use more fuel for no gain whatsoever.

Eh? It will still blow cold air through the vents, which is what you want on a hot day

It won't cool the cabin, though, which is the desired effect of 'climate control' in a vehicle.
You could also get quite cool from the windchill at 100mph if you stand up, but I wouldn't recommend that, either!

 

[omegabri]

Nope. It will just use more fuel for no gain whatsoever.

Eh? It will still blow cold air through the vents, which is what you want on a hot day

It won't cool the cabin, though, which is the desired effect of 'climate control' in a vehicle.
You could also get quite cool from the windchill at 100mph if you stand up, but I wouldn't recommend that, either!

Would cool your legs and chest though

 

[buzyg]

Think Pondi has been on the wine again. No problem using the air con with the roof down in any car. I cool the foot well. Definitely makes a difference in the open tops we have. Sure it uses a bit more fuel. But so does simply having the roof down in the first place.

 

[omegabri]

Think Pondi has been on the wine again. No problem using the air con with the roof down in any car. I cool the foot well. Definitely makes a difference in the open tops we have. Sure it uses a bit more fuel. But so does simply having the roof down in the first place.

Cheers

 

[B21]

For info from E89 TIS

The convertible program is activated in the factory. (this factory setting can be deactivated in the ”Personal Profile”.)

Switch-on conditions:

Terminal 15 ON
Soft top open
The convertible program comprises the following functions:

The condensation sensor is switched off
The blower speed increases with increasing driving speed
Air distribution is switched to the upper body and head, airflow to the footwell is throttled.
Ram air pressure compensation is changed, i.e. as driving speed increases, the air mass fed into the vehicle through the fresh air grille increases.
Solar sensor control variables are changed

When the soft top is open, the solar sensor evaluates the ambient brightness (darkness to intense sunshine) more strongly. For this reason, the solar sensor has a stronger effect on the IHKA controls when the soft top is open.

In the convertible program, the blower speed can be changed manually on the IHKA control panel. The automatic flap control remains active (no change to flap position).

If the convertible program is active and the flap positions are changed with the CID (Central Information Display) and controller, the convertible program will be deactivated. This means that manual settings will be assumed, unchanged settings will revert to those that the air-conditioning system had before the soft top was closed.

The convertible program can be completely reactivated by pressing the AUTO button.

 

[B21]

Think Pondi has been on the wine again. No problem using the air con with the roof down in any car. I cool the foot well. Definitely makes a difference in the open tops we have. Sure it uses a bit more fuel. But so does simply having the roof down in the first place.

Cheers

FWIW Argyll Andy has heavily used his air con on both his G29s at 35c+ temps

 

[r2uzenblot]

If it was an issue there would be large warning stickers all over the windscreen and the on board computer would set off sirens in these days of warnings about coffee can be hot in Costa

 

[enuff_zed]

Don’t know on G29 but the E89 was designed with air con being used roof down…

Utter bollox (again). No car was 'designed' in that way.
A/C is just a mechanical cooling system. I could explain how it works, but you probably know more about that than me already, so I won't.

So let's assume for a minute that you didn't just write that because it was Peter and you have a weird obsession with him. :roll:

The E89 DOES adjust the aircon when the roof is down, so that it blows only down into the footwells and I believe onto the chest area too, but not up the screen as that would be pointless.
Therefore the system must be fed information to say the roof is down otherwise it wouldn't adjust.
Whilst aircon is "just a mechanical cooling system", the direction of the airflow it produces can be controlled by the car. "I could explain how it works, but you probably know more about that than me already, so I won't. "

If I collect all your toys and place them neatly back in your pram will you promise to behave.

 

[Nanu]

Air con on legs if very warm, which is not often but definitely beneficial if static in traffic. Stylish cap also helps for those of us with thinning thatch

 

[Pondy]

If I collect all your toys and place them neatly back in your pram will you promise to behave

Nope, I don't do behaving. Spent too many years trying.....failed miserably so gave up.

I don't have an obsession with Peter, he just winds me up with his 'I know everything cos I've read all the books and Googled stuff, but have no practical knowledge in anything really'. It's OK, cos he dislikes me more and I'm on his ignore list so it doesn't matter what I say.
Sometimes reading his incessant, thinly veiled, 'I'm so much richer and more intelligent than everyone else' drivel just makes me reply. I don't do it very often anymore TBH.

I have only one obsession....it has four wheels and is in my garage. It's winding me up much more than Peter ever could, believe me.

 

[Zed Baron]

I don't have an obsession with Peter, he just winds me up with his 'I know everything cos I've read all the books and Googled stuff, but have no practical knowledge in anything really'. It's OK, cos he dislikes me more and I'm on his ignore list so it doesn't matter what I say.
Sometimes reading his incessant, thinly veiled, 'I'm so much richer and more intelligent than everyone else' drivel just makes me reply. I don't do it very often anymore TBH.

Clearly you have never met him, he's actually a nice guy who will offer help to anyone, guess you're having a bad day

 

[BigDave]

All very interesting..

And something else I have learnt about the car..

Everyday is a school day,...

I always turned the A/C off via the I drive when the roof was down, but now it seems I don't need to bother...

 

[Nanu]

I don't have an obsession with Peter, he just winds me up with his 'I know everything cos I've read all the books and Googled stuff, but have no practical knowledge in anything really'. It's OK, cos he dislikes me more and I'm on his ignore list so it doesn't matter what I say.
Sometimes reading his incessant, thinly veiled, 'I'm so much richer and more intelligent than everyone else' drivel just makes me reply. I don't do it very often anymore TBH.

Clearly you have never met him, he's actually a nice guy who will offer help to anyone

Yep, met once and agree

 

[Argyll Andy]

Think Pondi has been on the wine again. No problem using the air con with the roof down in any car. I cool the foot well. Definitely makes a difference in the open tops we have. Sure it uses a bit more fuel. But so does simply having the roof down in the first place.

Cheers

FWIW Argyll Andy has heavily used his air con on both his G29s at 35c+ temps

Last trip the highest we saw was 46.5 degrees heading back from Marbella, roof down, A/C up full blast 8+ hrs. Of course along with using it every other time the roof is down and above freezing