Air Conditioning Tech Thread.

[Z2TT]

It used to be called Hychill HR12, now called Minus30. It worked good in my Soarer GZ20 which doesn't have the best airflow through the condenser so it wasn't as good at the lights but when going I got 5 degree vent temps on a 40 degree day, and that is with a dirty condenser too.

It's more efficient than R134a and R12.... so in theory it SHOULD get colder but how cold you'll get is limited to how well your system is designed to transfer heat, e.g airflow through condenser, whether you have a fan that comes on to cool the condenser, and if not, airflow through grille. If it's very bad, then you probably won't get much performance increase from switching to a more efficient refrigerant.

It works just fine in R12 and R134a systems, as it was originally intended to be a Drop-in replacement for R12.

[dnegative]

I think the problem with the AW11 is air through the condenser, with normal cars the air goes through it and the radiator into the engine bay. On my MR2 is hits a front firewall about 5cm behind the thermos.

[matty12]

I spoke to my aircon guy a while back about HC12, and he said that he's seen many different products come and go over the years that were replacements for R12, and so far R134A was the only one that seems to be sticking around. So based on that he doesn't deal with HC12.

We had the same issues with FR12, some system just did not work with it, some of the problems ive been lead to believe with blends as they evaporate at different rates and so separate.


Alot of the jap stuff is easy to check the evaparators on by either pulling them out or taking out the fan speed resistor or blower fan to get a look at it. Granted you can only see one side though, or if its a big leak sometimes there is oil in the drain tube.

[maccac__1590]

anyone ever tried LPG? apparently it runs real well, except for being explosive haha

[dnegative]

Apparently it can also stuff your compressor too, you can use a lot of things (even ammonia)

The freeze30 stuff is flammable too

[maccac__1590]

i have heard of old farmers running it it tractors ect, and lasting as long as they keep topping it up and or until there is no oil left and the compressor seizes, i suppose it might depend on oil type, compressor type, how clean system is ect ect ect

[mick08]

I'm pretty sure theres a law about using lpg in automotive A/C systems, you wouldn't want to slowly gas yourself on a long trip, let alone the fire risk of lpg under pressure in a collision.

[Z2TT]

There might be certain regulations in Queensland only, but not in other states concerning Hydrocarbons.

You can use LPG in Auto A/C, however it is not as refined, so it would probably have high levels of moisture than what is acceptable.

Also depending on the blend of Butane/Propane in the LPG you put in, the pressures in the system may be too high than what it is designed for.

[briney]

i'd check with the aust. refrigerant council. i'm pretty sure you're not allowed to use hydrocarbon refrigerants (e.g lpg) in anything which moves under its own steam.

[maccac__1590]

oh yeah its dodgey as fuck and not to mention illegal, not being able to use hydrocarbons in something that moves under its own power rings a bell from somewhere.

would suck to have a few dodgey plug leads or something and develop a leek under the bonnet.....

also mick mentioned being gassed while driving, i suppose if it was leaking inside, is that another requirement of a automotive refrigerant to be non toxic? i have never really thought of it before

[The Witzl]

its cheap enough to get the proper gas - stop being a fkn tightarse!

Plus, the real stuff does seem to work pretty darn well... at least in my corolla.

[Rhyno]

The thing is if leaving it overnight, wouldn't the pressure of the nitrogen inside the system change as the ambient temperature outside changes, which if the day is colder the next day.... may fool one into thinking it's a leak?


Also is there any refrigerants your "allowed" to use for leak testing, so you can use a sniffer.

Nitrogen does not have a pressure/temperture relationship like refrigerant e.g. if you pressure test at 4pm then check it at 8am the next day if should not have moved. However when pressure testing with oil in the system (as in the compressor and in the evaporator due to "oil logging") you can small traces of refrigerant in the oil, which may cause the system to rise/fall by 50kpa. If the pressure goes up, you know this is the case and your all good. If it drops by more than 50kpa (7.251886886510461 in PSI, I use kpa as it is a more accurate measurement) then it is time to get out the bubbles...

In regards to refrigerants being allowed for sniffing the politicaly correct answer is no... However there have been many occasions where say, 100 kpa of gas is put in as a trace, then a proper pressure test of Nitrogen put on top of it, to give the sniffer something to sniff. This is the only way to accuratly diagnose hard to find leaks (like between steel walls for example, obvisouly not an issue in cars) after you have tried isolating your system, e.g breaking up your pressure test into different sections, high side/lowside for example. Once the leak/s are identified this mix must then be reclaimed and disposed off appropiatly.

This happens a fair bit on boats on the open sea's, no mister work safe or ARCtick guys floating around in the big blue Again this is not good practice, just highlighting that it was quite common in the "old days" but it still does happen, from time to time.

In regards to the design of leak testers, they come with a fan built in, that sucks the refrigrant in and samples it. Check out the CPS LS3000 for example, thats what I use from time to time.

Kind Regards,

Ryan

[Rhyno]

its cheap enough to get the proper gas - stop being a fkn tightarse!

Plus, the real stuff does seem to work pretty darn well... at least in my corolla.

Your right Witzl, just buy the best shit IMHO, as if done right, you will save money on econermy, and plus avoid the muck around of "testing" new refrigerants

[maccac__1590]

its cheap enough to get the proper gas - stop being a fkn tightarse!.

exactly, words of wisdom

[Z2TT]

If it were leaking inside, you would definitely smell even small amounts. Hychill has a strong odour so it's easy to smell even the smallest amounts.