Air conditioning

Philip Chidlow · Post by **Philip Chidlow** » Mon Oct 05, 2009 10:33 am

Following on from: http://www.bxclub.co.uk/forum/viewtopic ... hlight=r49

Any further advice/experience of R49 (aka R314) which apparently can be used in an R12 system without conversion? Even older systems which have been converted to R134a (with limited life expectancy it has to be said) can be flushed and refilled with this new compound. R12 was mineral-based. R134a is fully synthetic (and poisonous). This R49 is, apparently part mineral and seems to actually coat and protect the otherwise vulnerable inner workings (pipes/linings) of elderly AC systems. You can even retain the rubber seals.

AlanS, you are sorely missed.

BX Bandit · Post by **BX Bandit** » Mon Oct 05, 2009 11:31 am

I have taken advice but not done this yet....but a drop in refrigerant was suggested by my a/c bloke to be far easier and from memory slightly better at cooling than R134a. I can't remember the name/code of the refrigerant although R314 rings a bell. When I come to get mine done that's the route I'll go - the R314, not the conversion. The PAG oil needs changing as well if you convert and it's apparently horrible stuff.

Post by **mat_fenwick** » Mon Oct 05, 2009 11:59 am

I believe that R49 and R413a (which may be what you had been told about Bandit) are essentially the same thing. I've not heard of R314 before, but that doesn't mean it doesn't exist.
I was recommended to use RS24 (R426a), and that has stayed in my R12 system for 3 years now (original oil but all seals replaced with green neoprene ones). I can't be sure whether the 'recommendation' was based on knowledge or just what they had in...

BX Bandit · Post by **BX Bandit** » Mon Oct 05, 2009 12:43 pm

You're more likely right than me Matt, it was about a year ago I enquired and my memory gets re-set every night!

Vanny · Post by **Vanny** » Mon Oct 05, 2009 6:06 pm

I'll only get berated for this but why put in a poor performance alternative for the sake of £20? R12 is bad for the environment (CFC) but by far the best refrigerant for auto HVAC, its so good the Americans still use it as staple diet. After that the next best is R134, its not poisonous, it isnt CFC, it isn't as good as R12 but in an over spec-ed unit like the BX it makes no difference.

R12 to R134 conversion for the BX costs £5 in seals (£15 from Citroen as a kit), a high side converter and possibly a low side dependant on the pump at £2.00 each and some new oil £3.50.

Thats less than £10 to convert!

You'll need to drain, flush, and recharge the system and possibly replace the drier, but they are standard service items anyway.

All of the R12 drop in replacements suffer from performance loss either over prolonged use or on pull down (time it takes to get from warm to cool), so it might not be a notable loss even over a long time (remembering weather is mild in the UK) but there is little to gain from what will likely be a more expensive 'drop in' refrigerant.

Jaba · Post by **Jaba** » Tue Oct 06, 2009 4:31 pm

I have recently gone from R12 to R134a. I researched a bit and found that R24 and R413a are still available but I was unable to find any aircon man who uses it. There is just not the demand.

So in went R134a, new seals, new Ester oil (compatible with 134a and the mineral oil residues in the system), and a new drier receiver - this is essential as the original R12 drier's desiccant does not work with R134a.

I am happy with R134a's performance. At tickover after switching on, the air vent temperature is down to 8deg after 30 seconds and cuts out at 2 -3 degs after 45seconds. More than adequate.
Ultimately there is not as much cooling capacity as R12 but this is not noticeable at air temps below 30 degs.
I would love to try some of that Greenfreeze stuff that Alan used to advocate but you cannot get that here either. Any mention of it to an aircon man results in the party line lecture about it being inflammable and therefore too DANGEROUS to use in a car.

I see that the motor trade is going over to a new refrigerant in a year or two that is not a greenhouse gas like R134a but is unfortunately not as good a refrigerant as R134a.

BX Bandit · Post by **BX Bandit** » Tue Oct 06, 2009 6:33 pm

Jaba wrote: and a new drier receiver - this is essential as the original R12 drier's desiccant does not work with R134a.

Is this a case of a new and R134a compatible receiver dryer or just a new receiver dryer (as per OE spec) to avoid cross contamination between the old R12 and R134a in the system. Does that make sense?!

Vanny · Post by **Vanny** » Tue Oct 06, 2009 6:53 pm

Ah, 2012 refrigerant, what a bloody joke that is becoming.

There are two options, CO2 or R1234yf.
R1234yf is an actual refridgerant, i believe runs at a slightly higher pressure and realistically is the ideal solution. If you believe the hype from the German manufacturers then it is super flamable and will combust if you talk about it, which is rubbish. It is certainly not as good as R134 and terrible compared to R12, the Americans wont accept R1234 or the CO2 systems so there is a good chance manufacturers will have to develop both.
Only a few German manufacturers have stated they will be using the CO2 option. Great refridgerant as obviously it does relatively little harm to the environment, but its perfromance is pretty hopeless and the only way to get any acceptable performance is to up the opperating pressure. Instantly all your AC components become considerably bigger and heavier making fitment an absolute pain and when all cars are trying to be lighter this is not good.

Well thats my view as best i know it, i'm trying not to keep on top of that aspect of the industry as it changes soooo quickly

BX Bandit · Post by **BX Bandit** » Tue Oct 06, 2009 7:26 pm

you could recover the co2 from the emissions and have a constant top up...............I'll get me coat........