Been driving cars with air con since 2004 . When summer comes I sometimes pop it on, always amazed at how cold it is, my point is this, I have NEVER ever had the system recharged on any car, simply because I think doing so, it could not get any cooler . . .is it a waste of money ? 2017 SEAT Ateca 4drive 2.0 xcellence (May 2022 -
2007 HSE with HST bodykit in Zermatt Silver 169,700 miles (dec 2016 - May 2022 )
2007 Honda Civic Type S GT (2012-2017)
2002 Mini Cooper S (2008-2012)
1992 Honda Legend 3.2i (2003-2008)
1990 Honda Concerto (1999-2003)
1985 Honda Accord (1997-1999)
1983 Honda Accord (1993-1997)
1983 Mini Mayfair (1988-1993)
1974 Mini 1000 (1979-1986)

It's a waste of money if it doesn't need doing! As far as I know, people get their cars re-charged because some of the gas has leaked out over time through dry seals etc (probably from under-use of the system). A good garage will measure the temperature of the system before re-charging and will not go-ahead if it doesn't need doing (i.e. if they will get no improvement). Even Kwik-fit do this!

when doing an air con recharge they should also flush out the system as the bacteria that reside in the pipework and components can be pretty horrific.
the advice is to turn it on periodically if not on all the time, and to have the windows open for the first 5 minutes or so in order than any bacteria will then vent out the windows.
plus air con is not just about cooling but also dehumidifying the air, so air con helps in winter too preventing misting up etc

Don't turn it on periodically - don't turn it off EVER

Cooling the air lowers its dew point and so water condenses out = air is far dryer, useful in winter as it keeps the screen clear and stops the car getting moldy.
The seals benefit from the lubricant in the refrigerant and dry out causing refrigerant loss if they aren't lubricated.

The "radiator" (heat exchanger) that provides cold air is obviously cold, when you stop the engine moisture condenses on this radiator, if left bacteria grown on it. this not only gives the car a musty smell, the bacteria being blown into the cabin is not good for your health.

Yes it does marginally increase fuel consumption - nowhere near as driving at above 30mph with a window open, but you are driving a 2 tonne brick with the aerodynamics of barn door, if fuel economy (and running costs in general) is that much of a consideration you should really be driving a Fiat Panda Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Use it or lose is the way a/c has been described to me. Mine is on constantly unless I'm driving with windows open. Landrover - turning owners into mechanics since 1948

2014 Orkney grey Freelander SD4 GS.
2004 Zambezi silver Discovery 2 Td5 (Gone)
1963 Surf blue Morris Mini Minor Super de Luxe (my little toy)

I was told AirCon costs you 10% more fuel ??? or 10% less BHP ??? whichever ??

I think that was in the early days of car air con when they were fitted to 1 litre vehicles and had a noticeable effect. I believe the systems are different today and have less effect on the engine. I did try 'no air con' tests on previous vehicles to see if it made a difference in fuel economy but never noticed any. Otherwise I leave it on all the time. 
Hung like Einstein, smart as a horse.

The schrader valves for my 2008 LR2 si6 are pricey, especially the low side...........they appear to be non standard and not carried by none. And, I agree with Bob, use it or loose it.

3landertwo wrote:

I was told AirCon costs you 10% more fuel ??? or 10% less BHP ??? whichever ??

Andy131 wrote:

Don't turn it on periodically - don't turn it off EVER

Cooling the air lowers its dew point and so water condenses out = air is far dryer, useful in winter as it keeps the screen clear and stops the car getting moldy.
The seals benefit from the lubricant in the refrigerant and dry out causing refrigerant loss if they aren't lubricated.

The "radiator" (heat exchanger) that provides cold air is obviously cold, when you stop the engine moisture condenses on this radiator, if left bacteria grown on it. this not only gives the car a musty smell, the bacteria being blown into the cabin is not good for your health.

Yes it does marginally increase fuel consumption - nowhere near as driving at above 30mph with a window open, but you are driving a 2 tonne brick with the aerodynamics of barn door, if fuel economy (and running costs in general) is that much of a consideration you should really be driving a Fiat Panda

Andy131 wrote:

....... if fuel economy (and running costs in general) is that much of a consideration you should really be driving a Fiat Panda

what like this G4 4x4 Challenge ???? looks like yours.

Andy131 wrote:

3landertwo wrote:

I was told AirCon costs you 10% more fuel ??? or 10% less BHP ??? whichever ??

When 40bhp was a good output for a family car, 4hp for the air conditioner was 10%.
Now you have 160bhp, 4hp is 2.5%
So if it makes 2.5% difference and you only get 30mpg, then the aircon is going to make 0.75mpg difference - you are not really going to spot that unless you drive for 12 months with the aircon off and do EXACTLY the same route and have the same traffic as the previous 12 months with the aircon turned on - that's what labs are for.

I dont understand the comments suggesting never turn it off, or keep it on forever . . . . .mine is either aircon or a heater, so in winter I will use the heater rather than freeze myself to death  2017 SEAT Ateca 4drive 2.0 xcellence (May 2022 -
2007 HSE with HST bodykit in Zermatt Silver 169,700 miles (dec 2016 - May 2022 )
2007 Honda Civic Type S GT (2012-2017)
2002 Mini Cooper S (2008-2012)
1992 Honda Legend 3.2i (2003-2008)
1990 Honda Concerto (1999-2003)
1985 Honda Accord (1997-1999)
1983 Honda Accord (1993-1997)
1983 Mini Mayfair (1988-1993)
1974 Mini 1000 (1979-1986)

I always use the AirCon in the winter to clear the inside 'fogged' up screen.

3landertwo wrote:

I was told AirCon costs you 10% more fuel ??? or 10% less BHP ??? whichever ??