AC - on or off

[Dermottdog]

Hey

What are people’s thoughts on wether the AC should be on or off.

Reason for asking is a few years ago, we got a brand new Golf. The manual stated that it’s best to leave it on and at 21 degrees throughout the year for maximum comfort. This we did. Three and a half years later and out of warranty, the AC compressor failed. It’s not a serviceable item and the part alone cost about £1000 if memory serves (genuine VW part).
In all the other cars I’ve owned since, we use the AC in the winter to clear mist from the screen and AC in the summer to cool the car down but never is it left on all the time. Since picking up our car last September, the AC has always been on.

Your thoughts please....

[Silver Moose]

I'm no expert but I think an a/c compressor is more likely to fail through lack of use than continuous use.

As I (think I) understand it, the circulating gas keeps the motor lubricated and the seals in good order. Having said that, I have had V.A.G, cars and, on some models, bad design can lead to pipes rubbing and gas leaking - this can kill a compressor fairly quickly.

My personal choice is to keep it running & keep on eye out for any reduced performance that may suggest a gas leak.........it's a shame that, with the multitude of sensors on modern cars, they don't have pressure sensors in the a/c system.

[Silver Moose]

P.S: Main dealers for all manufacturers will tell you components are not serviceable - they employ fitters, not mechanics!

Go to an independent and you'll find they're doing quite well out of reconditioning these "unserviceable" compressors

[Deleted User 2478]

My experience is that on cold and dry weather AC will in fact stay turned off in Auto mode, even when the symbol AC On is shown on the screen. As soon as humidity starts to build up inside the car (2-3 passengers) AC will turn back on to reduce moisture level.

[72 dudes]

I'm in the "Aircon off" camp.

I totally get that the compressor needs to be regularly used however to keep bits lubricated and working, so I will make a point of switching it on during the winter months, maybe for 10 minutes a week.

No point in having the compressor running and using fuel when it's not needed.

I've never had any problem apart from the occasional re-gas

[stu22]

The clutch on the compressor should only engage when in demand, so makes little difference 99% of time.

[Dermottdog]

The clutch on the compressor should only engage when in demand, so makes little difference 99% of time.

True. I suspect the electromagnetic clutch failed on the Golf. When I pushed the AC button, there was no noise from the system and the engine didn’t load up.

The old 1999 Shogun we just sold had a leak from the AC system due to age but also lack of use. As already said, seals harden and let pressure by. When refilled with new gas, it was very efficient (lasted 5 or 6 months).

[Deleted User 2558]

I set the car to Auto, in fact it was on Auto when I bought it, and haven't touched it since.

[ACertainAge]

When I need it, to clear misting up or more agreeable feel in the summer I turn it on, otherwise it is off.

[Salmonfisher]

Soon steams up if off but maybe I'm a heavy breather. I always leave it on.