Thread: Dangers of using Hychill AC gas

My 24yo tractor had its 1st a/c re-gas today using the same R134A that was used initially. I don't know whether that's good or bad but the a/c works again after stopping a few days ago, found to be due to low pressure.

So, ummmm....whose game enough to mention bbq gas and aircon in the same sentence....

This is a very emotive issue and there is a lot of skewed evidence out there. I believe in the science and the proven use of hydrocarbons for decades over multi nationals pedaling their vested interests.

I've had Boral ER12 in my D2 4.6 for nine years without any issues or re-gassing. After an altercation with a member of our outback wildlife, I repaired the vehicle, installed a new condenser and drier, replaced all the "O" rings and seals and vacc'd the system (I've got refrigeration equipment). As I'd let my license lapse (retired), I had it checked and gassed by a professional frigie in Alice. The a/c system works far better and chills down a lot quicker in our outback 40++ heat.

My bro inlaw has had the same gas in his Hilux for even longer, also without issue or re-gassing.

If I had to think about it I feel far safer with a few hundred grams of hydrocarbon in my a/c system than up to 170 litres of premium petrol sitting in my fuel tanks.

Ask yourselves this, why is the US & the EU phasing out R134A.

If your into heavy reading here's a link on Hychill's site to the report prepared by Granherne for Boral (Esanty Refrigerants) for their ER12 hydrocarbon refrigerant for use in automobiles.
https://hychill.com.au/media/pages/i..._report_sm.pdf

A link to Hansard re Esanty
https://parlinfo.aph.gov.au/parlInfo...-09-29/0000%22

Originally Posted by johnp38

So, ummmm....whose game enough to mention bbq gas and aircon in the same sentence....

There's the thing. It's not BBQ gas. It's an approximately 60/40 mix of Propane (R290) and Iso-Butane (R600a). Straight propane will have pretty high head pressures and a greater chance of doing some pressure related damage.

Here is a PT Chart I knocked up a few years ago to try and illustrate this to a muppet who was insistent on putting "BBQ Gas" in his AC.

Y : Pressure in PSI. X : Temperature in C.

In this context OZ-12 is an approximately 60/40 blend of the 2 hydrocarbons (which is what Hychill is). It's a pretty close match for R12. When replacing R134a in a system reliant on pressures (like the old school suction pressure regulated variable displacement compressors) you need to up the propane component a bit or the evap will freeze. All the modern stuff seems to be controlled on evaporator temperature, so it seems to work fairly well.

So it's not just "BBQ" gas.

That PT chart is not much good for us fridgies,we need it to run a lot lower than 10 degrees C

You have actually done a better job than the Local TAFE that the boys did their Hydrocabon course at,they didn’t even have a PT chart for the commonly used Hydrocarbon refrigerants.
After a good few complaints from the students,they found one.

A capillery selection chart would have been good as well,but no luck there either

I guess this is what you are referring to, Brad:


Wholesale Refrigerant - Cheap R22 Freon, R22a, R410a, R12a, R134a Replacement (frostycool.com)

HC-12a, also called ES-12a, OZ-12a, DURACOOL 12a^[1] and Hydrocarbon Blend B, is a "drop-in" replacement refrigerant for Freon-12 and to a lesser extent, R-134a.

Originally Posted by scarry

That PT chart is not much good for us fridgies,we need it to run a lot lower than 10 degrees C

You have actually done a better job than the Local TAFE that the boys did their Hydrocabon course at,they didn’t even have a PT chart for the commonly used Hydrocarbon refrigerants.
After a good few complaints from the students,they found one.

A capillery selection chart would have been good as well,but no luck there either

I generated those out of Refprop. It's easy enough to generate arbitrary mix charts and I'd be more than happy to sort an extended chart, but to be frank below about 20C it follows the R12 line pretty closely. It does make it easy to tweak the gas mix to suit the evaporator pressure, but it's pretty application specific.

As for capillary, I've been tweaking empirically because the behaviour in a cap tube is a bit different to the CFC/HFC. I have an interesting unit here with a double evap (for a vacuum distillation still). It's a 12/24V danfoss variable speed compressor which runs one conventional tube based evap at ~-5C and then a second flooded evap at ~-20C. That took a *lot* of tuning to get right and it is extremely condition specific, so I have to wait for it to properly pull down to temp for it to work right. I played initially with EEV's, but I can't buy an EEV with a small enough orifice to make it reliable. I have a selection here, but they're all suited more for A/C applications 1.6KW and up. That makes use in a 40W system problematic.

Originally Posted by Old Farang

I guess this is what you are referring to, Brad:

Sort of. Using the software I used to produce the pt for each refrigerant I used the OZ-12 blend as it was already built in and didn't have any significant additives. A lot of the blends mix in HFC refrigerants for various proprietary reasons. I just picked the one that was the closest to a pure HC mix that Hychill sell. That was produced pretty quickly to illustrate R290 having a 50% higher pressure at 60C to prevent some neanderthal doing something dumb. "Ugh, but it blows real cool dude".