Air Con doesn't seem very good

[FROSTYBALLS]

It was a response from one of the staff on HJ's website to a question asked of Honest John.

[Stivino]

19 minutes ago, FROSTYBALLS said:

It was a response from one of the staff on HJ's website to a question asked of Honest John.

Therefore, not an expert on air con.

[FROSTYBALLS]

Believe what you want.

[Stivino]

30 minutes ago, FROSTYBALLS said:

Believe what you want.

Thanks, I will.  And I'll stick to believing proven scientific facts not hairy fairy stuff that could be written by anybody.

[yossarian247]

I have contacted 'Honest John' in the past regarding some slightly dubious advice he'd given re. VW diesels and he freely admits he's just a journalist who writes about cars and has no specific technical knowledge. In fact he said that a lot of the information on his website and in his Telegraph column comes from letters and emails readers have previously sent it.

[Mooly]

Many will probably wonder why vehicle A/C systems such as these need such specific 'care' while domestic fridges/freezers which are exactly the same in operation do not.

The reason is simply that the domestic refrigeration is classed as 'hermetically sealed' and that in essence means it is a closed and sealed system. All pipework and joints are brazed/welded together with no couplings, seals and flexible hoses and consequent possible areas for gas to escape. Then there is the compressor that pumps the refrigerant around the system. The domestic one is to all intents and purposes 'sealed' into a single metal can that is welded together. The only entry point is for the electrical cable and that can be sealed up pretty much 100%. The vehicle compressor has the rotating shaft brought out of the compressor in order for a pulley to be attached and to enable it to be driven from the engine. This rotating shaft/seal interface is often the biggest cause of natural leakage in a system and the way to keep it sealed is to run the system to ensure it is always lubricated and moistened with the oil in the system, most of which resides within the compressor. A small amount of the oil gets circulated around with the gas and that keeps the seals at all the other joints flexible and supple preventing leaks.

Whether to run a system all the time the vehicle is used or whether to run it briefly as preventative maintenance is an interesting question. Which would have the lowest leakage rate? I suspect there are pros and cons for each and probably there is a point where the two regimes cross over. Wear is another obvious factor. A system not running is suffering no wear.     

[Mooly]

This is quite interesting, particularly from page 30 onward. It's an old document... however 🙂   

Establishing the Leakage Rates of Mobile Air Conditioners.

[FROSTYBALLS]

As regards the Honest John website, it was bought out of administration in February this year by Heycar. There have already been some changes to how it operates, so what might have been the case previously, may not be the case today.

[Merlin5]

My air con seems to be on point now.  Had a horrible musty  smell coming from the vents yesterday but that's gone now. 

 

 

[Mooly]

Good to see you have cool air again. What was done to fix it? 

 

 

[Merlin5]

6 minutes ago, Mooly said:

Good to see you have cool air again. What was done to fix it? 

 

 

Yeah,  they just re-gassed it.  He said he doesn't think it'll leak because there was still some old refrigerant in it.  Hopefully it'll keep on working! 

[Stivino]

10 minutes ago, Merlin5 said:

there was still some old refrigerant in it

That's because the rest had leaked out. i.e. if it's not on the inside, it must be on the outside.  How did it get from the inside to the outside?

[Merlin5]

1 minute ago, Stivino said:

That's because the rest had leaked out. i.e. if it's not on the inside, it must be on the outside.  How did it get from the inside to the outside?

Yes,  good point! Hmm, I'll have to keep my eye on it. 

[paul9]

They generally all leak, just very slowly. He's probably of the opinion that it all seems to be normal and correct. Meantime, get an AC sanitiser along these lines:

https://www.halfords.com/motoring/engine-oils-and-fluids/air-con/halfords-air-con-purifier-150ml-192496.html

A new cabin air filter might be due too, depending on your service schedule.

[Stivino]

Hopefully it's just normal seepage and with a bit of luck it'll keep enough gas in it so that it works for a few years.

[Mooly]

10 hours ago, Merlin5 said:

Yeah,  they just re-gassed it.  He said he doesn't think it'll leak because there was still some old refrigerant in it.  Hopefully it'll keep on working! 

As long as you keep on using it... 

Remember that in winter if the outside temperature is very low then it won't tend to run anyway. If it did the evaporator would tend to freeze up with moisture. So leaving it switched on 24/7 is even more important because the only chance it gets to run may be for a few minutes, perhaps only when you restart after parking and the engine bay is hot.

Good luck.    

[Konrad C]

On 5/23/2020 at 3:12 PM, FROSTYBALLS said:

There was a question and answer on Honest John this week re air con, and the answer was -

Most air conditioning problems in cars are caused by lack of use, usually because the driver has switched the system off during the winter/colder months. Air con systems in cars are not designed to be used in this way. They should be switched on 100% of the time, otherwise the joints dry out and allow the refrigerant gas to escape. In the worst cases (if the air con has been switched off for a very long time) the compressor will seize and fail.

I react to the first part of the statement regarding the lack of use of the air-con. My previous '98 Avensis Mk1 was the first car I owned with air-con. I learnt about using it for demisting. So it was used for that, as well as for cooling. I admit that I don't just turn it on for a few minutes every week, but the system was effective for years between before needing a re gas. The current car is the same, and the air-con comes on, when I need to demist the windows. Both cars air-con work well. 
Talking of re gas, more recent cars use R1234 refrigerant, that is more expensive and said to be more flammable than the previous R134. I wonder what users of this newer refrigerant experience compares with the older R134?


   

[ziauris]

If you want to check whether you have refrigerant in the system, take the plastic cap off the L(ow) AC pipe in the engine bay and press down the central mental tab with a screw driver. If you hear a hiss and gas comes out then you have some refrigerant in there. Do not do this took much as harmful for enviroment,. If not then nothing. Mine I got nothing so looking for a cheap refill.