Air Conditioning

[Prince]

I was driving along the motorway today in the heat...obviously windows up. So to keep cool I turned the air conditioning on and then I got to thinking... 'why does the air conditioning use up fuel?'

I was gonna research it when I got in but I thought this might be a good topic for everyone to have a look at.

[pgarner]

the engine has to drive the compressor for the pump. bigger strain on the engine so loss in performance and more fuel used

[HDi fun]

The fuel usage is nowhere near as significant as the supergreens will tell us. It's best to leave the AC compressor on all the time as this keeps the refrigerant and gas borne lubricant in circulation. Which goes a very very long way to stop seals failing and causing system leaks.

The supergreens need to consider that it's ILLEGAL to vent R134a into the atmosphere because it's extremely bad for the environment on general and very very bad for their beloved ozone layer.

[DaveyL]

To be honest,running any electric device is worse for environment. More strain on alternator/compressor so more power. Changing to an electric fan, not mechanical, unlocks 4 horses on some cars. Thats just cos electric can run when needed, not all the time.

Dave

[glaymore]

i dont think i could have lived with running the aircon all the time on my car, it sapped 12hp from the engine

[Shao]

had it on yesterday as was doing "town" driving and couldnt go fast enough to get draught thru windows and jeeez the fuel remaining gauge just plummeted!

[HDi fun]

I've only had 2 cars in the last 10 years - yep, keep 'em a long time and drive 'em a long way. Both of which were fitted with factory a/c as standard.

Both of them disengaged the compressor clutch under full throttle acceleration so there's no problem with overtaking shove.

I thought this was pretty much normal practise.

[Izo Azlion]

I run the air con most the time, if only to keep myslf comfortable. I've not noticed a huge loss in power at all... maybe I'll give it a hard drive with the aircon off.

[HDi fun]

Diesels make a far better job of driving ancillary components as there's so much more power available at sensible driving revs

[Prince]

What's worse though... the small loss of power from the air con, or the drag you get with the windows down?

[pgarner]

i never drive above 30mph with the windows open theres too much noise.

unless its really warm i have the climate control set at 21 degress and i dont notice that much of a difference between running it on Auto (air con on ) and the Econ setting (just the fan running)

[Izo Azlion]

Originally Posted by pgarner

i never drive above 30mph with the windows open theres too much noise.

unless its really warm i have the climate control set at 21 degress and i dont notice that much of a difference between running it on Auto (air con on ) and the Econ setting (just the fan running)

I was a passenger in my friends street Ka (Convertible one) - had my beck resting against the head rest, with my head above the windscreen at 40mph - sunny, drunk and funny.

I love having my arm out the window and just feeling the air, tbh, at least when its this sunny

[HDi fun]

Or the five hundred quid to replace the compressor that's seized