How 'cold' should air con get?

[NightPHEVer]

Hmm, when set to 15oC, after about half an hour of working ok(ish) my aircon symbol starts flashing now. At that point the cold air seems to cease. I'm going to have it checked soon as I also now have a cracked windscreen which will have to be replaced, which I'm going to have done at my local Mitsubishi main dealer, as the bloke they use to change windscreens seems to know what he'e doing. Not always my experience with certain other well known windscreen fitting companies, usually affiliated to insurance companies.

 

[EchoVictor]

I had my air con topped up recently at a local tyre and exhaust place. I was looking where to take it and noticed that ATS (a U.K. chain of tyre fitters) charge more for an air con top up for a hybrid than a 'normal' car. Any idea why?

 

[NightPHEVer]

Well it looks a bit complicated but there are (I think) two condensors, one for the cabin air con and one for the batteries. The batteries have their own air con to keep them at an appropriate temperature, as they generate a lot of heat I guess - this can even happen while they're charging from the mains I believe. So I'm thinking there is more gas needed than non PHEV systems? I'm not sure if all the gas goes into the same place for the entire air con system or whether there are two filling points.

 

[NightPHEVer]

Had my aircon checked - and as a result re-gassed - today. Apparently 189g of gas/lubricant was removed from the system and 600g put back in. It now blows icy cold at 15oC which it's never done since I've had it. It has usually blown fairly cold but never really cold. So 411g of gas had gone somewhere. Apparently no leaks were detected though. Let's hope they're right about that! My PHEV had only done 3000 miles in the first 2 years of its life, so I'm wondering if lack of use of the air con caused loss of gas? It's suggested from various sources that 10% of gas is lost in 12 months of avaerage use. There's a very comprehensive (and slightly worrying) explanation of auto air con on HonestJohn.co.uk

So am I right in my interpretation of the Mitsibishi 'Technician Training Guide' (which might be Australian) that the main battery is cooled by air conditioning if needed? Is this in fact the case with all PHEV's, or just Australian versions? I'd have thought due to the complexity of the design that all PHEV's are the same. In which case presumably the air conditioning needs to be in full working order to cool the battery. Would this not be a safety issue then, or at the very least a risk to the longevity of the battery. You'd have thought the system would give out some sort of warning if there was any risk to the battery?

 

[AndyInOz]

In case you missed it, somewhere in the manual, it is mentioned that it is important to run the air conditioner at least five minutes every week.

Otherwise, seals dry out, and leaks can occur.

The air-con comes on to demist the car, so this should not be difficult to achieve, unless you deliberately turn it off.

 

[NightPHEVer]

Well yes, as you say that should happen anyway. I'm pretty sure that the cabin timed pre-heat in the winter is air con too. Obviously timed pre-cool in the summer would be too, but I've never used that 'cos it's not very hot in my garage. Also of course - assuming that the batteries are cooled via A/C if necessary (which I think they are) - then that would come on as well, even when the batteries are being charged, if they get sufficiently hot.

My concern was that as the vehicle can't have been used much in its first 2 years of life then the air con wasn't used enough either, so the seals may have dried out allowing gas to escape - hopefully not causing permanant damage. Bit hard to tell unless it's checked again in 12 months time to see how much has escaped. The loss of 411g of gas in 3 years does seem a lot.

 

[AndyInOz]

If it is leaking gas, the next phase is for the service crew to add dye to the gas, this leaves a visible trace where the leak is, and then you know which seal (or seals) to replace.