After a couple of warm days in the UK I noticed my air con makes no difference, not great for the German Shepherd. I'd like to top it up with R-1234yf but after researching I'm getting mixed opinions. It looks pretty straight forwards and there's a decent saving doing it ones self. Has anyone got any advice?

I've got a -    KAROQ SE L TSI DSG / Year of manufacture    2020 / Gearbox    7 speed SEMI AUTO

Cheers

Will

2 hours ago, Mr-Will said:

I'd like to top it up with R-1234yf but after researching I'm getting mixed opinions. It looks pretty straight forwards and there's a decent saving doing it ones self. Has anyone got any advice?

It is illegal to DIY recharge air con.

Thanks for the info @Paws4Thot . I would never guess it was illegal but I suppose this makes sense as it's a flamable gas.

So, for entertainment purposes only it a simple procedure, I've been quoted upwards of £130 for a top up at kwickfit.

It is certainly illegal to recharge a A/C system without first identifying and repairing the cause of loss of refrigerant.

Believe it is a requirement for ref. engineer to be certified.

The reason for this is reduction of uncontrolled releases of greenhouse gases.

Thanks @Warrior193 , my understanding is that the updated R-1234yf has smaller molecules then the more pouting older version R-134a. This is a bit like a kids helium balloon loosing it's lift after a couple of days because the smaller helium molecules escape through the membrane of the balloon.

As a result the aircon system starts running low after a couple of years and needs topping up after five years. It's sensible to make sure there are no leaks etc before doing anything but has anyone got any knowledge.

Just let me know if air con is taboo

Recharging A/C systems is covered by several Gov. regulations in UK (& EU)

A secondary breakdown product of HFO refrigerants such as R1234yf is HFC-23 - a very potent greenhouse gas (reported as 14,800 on GWP100 scale)

Another reason for the regulations is that the remaining gas in the A/C system must first be recovered correctly.

My understanding of most recent ref. gases is that they are commonly a 'cocktail' of different gasses and lubricating oil, the system must be completely evacuated before being leak-tested. The refrigerant charge must then be replaced completely.

My understanding is that partial re-charging will result in incorrect proportions of gas and oil in system.

I had a car from a different manufacture from 2015 to 2021, which had the newer type of fluid. Every year without fail the aircon wouldn't work in the spring, which was down to lack of fluid. Every year the tried to fix it. Vacuum leak test, double doses of dye, never found the leak. Every year had interesting discussions with service managers about how the fluid should last more than a year, they can't fix it, and I shouldn't have to pay. Was like it until I sold the car.

... While on the other hand, my Octavia A/C is still working with the original refrigerant charge from 9.5 years ago - There, that's gone and put the kiss of death on it! 🙃

Thanks for all the advice. I understand that it is a legal requirement to have the air con pressure checked before recharging. The recharging is legal if it's been tested hence being able to buy it from Halfords. It's also a consideration that the oil to gas mix might mess things up so it's a good idea to drain the system first.

With this in mind it doesn't look more complicated the refilling a gas cigarette lighter?

It is a legal requirement that the remaining refrigerant must be recovered and disposed of correctly.

The new charge then requires to be weighed into the leak-tested and evacuated A/C system.

Had mine done last month, during annual service. Whole job of drain/recovering, recharge, including dye and oils, check all hoses, belts, connections, and then ZACBOMB freshener, total £139 inc vat. And, as dealer job, fully guaranteed if any problems later, like leakage.

32 minutes ago, Choclab said:

Had mine done last month, during annual service. Whole job of drain/recovering, recharge, including dye and oils, check all hoses, belts, connections, and then ZACBOMB freshener, total £139 inc vat. And, as dealer job, fully guaranteed if any problems later, like leakage.

The price seems to have gone down. It was in the £200 range when the new fluid was introduced.