Aircon efficiency over time

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Fri 13 Apr 2007 10:43
Aircon efficiency over time - oldgit
I have a MK V Golf with 'climatic' semi-automatic Aircon and at this time of the year, often become paranoid as to whether it is working at its most efficient. I have read that one can expect the system to lose gas at up to at least 10% per annum which means that after 2.5 years use, mine could be down by at least 25%?

Does anyone have any figures as to what the face level air vent temperatures should be for a fully efficient system? I have placed a quality mercury bulb thermometer about 2" into the the central face level vents and run the aircon at 1500rpm with all the air directed through these vents and on 'recirculation' and have obtained a minimum temperature of 4ºC - this with an outside temperature of about 18ºC.

I was wondering whether this value was typical and in the right range for a system in good working order?


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Fri 13 Apr 2007 10:50
Aircon efficiency over time - L'escargot
......... and have obtained a minimum temperature of 4ºC - this with
an outside temperature of about 18ºC.


It sounds very good to me. If the ambient air temperature had been below 14 the outlet air temperature could have been below zero and the face vents might have started to ice up!
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L\'escargot.
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Fri 13 Apr 2007 11:05
Aircon efficiency over time - Quinny100
4 degrees at the vents is pretty much spot on what it should be. If you run the aircon all the time, as most cars with CC do unless you specifically turn it off, the loss of gas will be much lower than a system only run occasionally.
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Fri 13 Apr 2007 11:14
Aircon efficiency over time - Group B
I was going to say the same thing, get it much colder and you risk getting frostbite...
www.guardian.co.uk/print/0,,4731265-103690,00.html

The article above says Jaguar's system will not blow air colder than 3'C, for safety reasons, althought that didn't help the driver in question.

I had my aircon re-gassed last month and I don't think mine is blowing as cold as 4'C (it doesn't feel that cold - but I haven't measured it).
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Fri 13 Apr 2007 11:20
Aircon efficiency over time - L'escargot
the loss of gas will be much lower than
a system only run occasionally.


My car's handbook advises switching off the aircon when it's not needed.
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L\'escargot.
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Fri 13 Apr 2007 11:24
Aircon efficiency over time - Stuartli
I have a pal who runs an A/C servicing outlet - he reckons (he would of course!) that such systems should be regassed every two years.
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What\'s for you won\'t pass you by
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Fri 13 Apr 2007 11:26
Aircon efficiency over time - Stuartli
PS

If the outside temperature is 5 degrees C or less, my A/C system (and that of most cars apparently) will not allow full recirculating mode.
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What\'s for you won\'t pass you by
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Fri 13 Apr 2007 11:53
Aircon efficiency over time - John S
oldgit

I do wonder if there's something in this. After 6 years the aircon on my BMW didn't appear to be working as well as it used to. The aircon had never been turned off since I'd had the car. I'd fitted a new pollen filter. However, an aircon service showed it still had over 90% of the correct mass of fluid. The refill with the correct mass made little, if any, difference. Vent outlet temperatures were correct, around the 4 deg. mark as best I can recall. I'm still not sure if the system efficiency had dropped or I was imagining it.

JS
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Fri 13 Apr 2007 21:26
Aircon efficiency over time - Micky
Bring back R12.
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