Hydrocarbon refrigerant AC gas - (W140)

[sc_rufctr]

(I tried asking the question on a Mercedes forum but got zero replies)

Hi all, The air-conditioning in my car (1992 Mercedes S420 W140) still works but it's not as cold as it used to be. Not bad considering I've owned the car for well over 5 years! I'm planning on getting it serviced soon but a friend of mine suggested using a "Hydrocarbon refrigerant gas" instead of the standard R134a. I live in Australia and we can't buy R134a without a refrigeration licence so my only option is to go to a licenced service tech... But I'd prefer to DIY and I can buy and use "HyChill Minus 30" Hydrocarbon refrigerant gas in Australia legally.

All I need is a a gauge set and vacuum pump. (I'd get the R134a extracted by a local garage)

Has anyone done this and how did it work out?

See here for more info on the gas I plan to use... https://hychill.com.au/products/minus-30

This is the label affixed to my car.



W140 As a daily?

[asphaltgambler]

If it were me, I wouldn't mix different types of freon. The best bet if you can't buy it as a consumer, take it to a shop that you trust. It's likely just needs a top off.

[rfuerst911sc]

Based on the info in the link you provided I see no reason not to use it . The propane/butane cocktails have been around a long time under various name brands . If I am not mistaken European car companies are looking into using similar .

The website did recommend flushing existing system and use a specific oil . But it also says compatible with all refrigerant oils . I would call them and get clarification on that . If you end up using it please report back your results.

[jrj3rd]

If you have to go to the local ot get the R134 extracted just get them to take care of adding R134. Youa re already paying the labor to do most of the work. R134 isn't that expensive compared to buying the right equipment to do it all your self.

[GH85Carrera]

As far as I know, all hydrocarbon (propane and such) are illegal for road use in the USA. That certainly does not stop people from using them. They are a potential firebomb in an accident. A crash hard enough to get to the engine compartment can rupture those lines and make a nice cloud of extremely flammable gas in your nice hot engine compartment.

And don't say yea, what about the gas tank. The gas tank is in a protected area inside the frame, and liquid gasoline is not that flammable. One when it is vaporized is gasoline flammable.

So a 15 MPH hit on the front end will make the crumple zone (engine compartment) crumple, and make a nice cloud of explosive. Your insurance company might want to know about that and deny coverage.

Look up the DOT and EPA regulations on hydrocarbon refrigerants. Make your own choice.

If the AC worked properly when new, more than likely is just needs a competent pro to diagnose the problem and fix it properly. It could be a clogged orifice tube, or expansion valve, or simple low on charge. Don't just dump in more refrigerant, as that can make the problem worse when working blind.

No way will I ever use propane in my car as a refrigerant. Vehicles that use propane or natural gas have those high pressure tanks in safe part of the car, and the tanks themselves are pressure tested, and have to be replaced after a number of years. AC lines are very vulnerable.

[masraum]

Originally Posted by GH85Carrera

As far as I know, all hydrocarbon (propane and such) are illegal for road use in the USA.

He's in Australia. I don't think US DOT or EPA are too concerned with what he does with his car AC.

[red-beard]

Glen,

The issue is not fire in an accident. It is not a bomb. The amount of propane refrigerant is quite small and it is a gas and dissipates quickly. Gasoline is far more likely to cause a fire.

The real issue with propane refrigerant is that if a leak occurs in the evaporator, it is inside the cabin. The good news is that if a leak occurs, you will smell the propane, unlike R134A.

[nota]

all new small window AC units use the propane in the USA for the last several years
as do the floor units with hoses
many do also use propane in cars freeze 12 is one brand as the gas is way cheaper

the valves in the units may need to be swapped out

[Arizona_928]

I use a mix of propane and isobutane for a r12 system. It's also compatible with 134a. Volume differs though due to weight. So you'll have to do a conversion. I put a can in every year and I'm happy.
Flammability is on par with r12 without that fluorine to cause cancer (in the state of California).

I would agree with James on the bomb thing. There's no rapid expansion and under pressure it'll quickly vent or be a short lived propane flame thrower. But that's very unlikely as it's in the gas phase. Gasoline vapor is way more dangerous.

[sc_rufctr]

Thanks for the input... And yes it would be cheaper to get it gassed up/checked by a tech but I like being able to DIY.

Originally Posted by nota

all new small window AC units use the propane in the USA for the last several years
as do the floor units with hoses
many do also use propane in cars freeze 12 is one brand as the gas is way cheaper

the valves in the units may need to be swapped out

Do you mean the Schrader valves in the high and low ports? I had planed to swap those out & also replace the receiver drier.

[greglepore]

Given its a 140 and they have know evap corrosion issues, I'd think hard about this. Regardless, check out Cryoseal as a prophylactic.

[RANDY P]

I've done it on my W202 C36 and had it for a long time in my Silverado. Works killer in high temps, in my truck in cooler temps had a hard time due to evap icing, difficult to get the pressures just right for wide range of operation.

Would I do it again? Probably not due to safety issues.

rjp

[nota]

Originally Posted by sc_rufctr

Thanks for the input... And yes it would be cheaper to get it gassed up/checked by a tech but I like being able to DIY.



Do you mean the Schrader valves in the high and low ports? I had planed to swap those out & also replace the receiver drier.

no the internal metering valve that controls the pumped gas flow rate called a TVX

the schrader valve is to get gas into the system and F12 vs F134 are different to prevent
useing the wrong gas

many report propane works in some systems with the stock valve
others do not work as well

https://www.hvac.com/resources/txv-valves-and-how-they-work/

AS RANDY SAID ICE IS A TVX ISSUE

[mattdavis11]

Ice forming on the evaporator is a charge issue most of the time. He has a block style expansion valve (internally balanced) which is completely different (externally balanced) from which Randy (link above) is talking about on a HVAC or section 608 of the EPA, not 609 which is MVAC.

I would replace the Schrader valves, pull a vacuum and charge up with R134a, a HCFC.

[Bob Kontak]

Originally Posted by mattdavis11

II would replace the Schrader valves, pull a vacuum and charge up with R134a, a HCFC.

He can't buy R134a.

We can buy R134a all day long if purchased in the 12 oz cans. 609 certification is required for 30 pound jugs.

[nota]

research shows why not to use ordinary cooking propane

one it ain't pure propane got butane and WATER in them BBQ tanks

refer r290 is pure sans water or other gas costs more but will not kill you system with corrosion
like water will

a Propane/Propylene mix is a bit better cooling

Thermodynamic performance analysis of eco friendly refrigerant mixtures to replace R22 used in air conditioning applications
SV Shaik, TPA Babu*- Energy Procedia, 2017 - Elsevier
In the present study theoretical thermodynamic performance of a 0.8 TR window air
conditioner with ten binary refrigerant mixtures consists of propylene (R1270) and propane
(R290) was investigated based on actual vapour compression refrigeration cycle. All the
investigated refrigerant mixtures consist of zero ozone depletion potential. Global warming
potential of R22 is 1760 whereas GWP of all the studied refrigerant mixtures were below
three and also these mixtures are closer to azeotropic containing the temperature glide*…

[Bob Kontak]

Originally Posted by nota

research shows why not to use ordinary cooking propane

one it ain't pure propane got butane and WATER in them BBQ tanks

refer r290 is pure sans water or other gas costs more but will not kill you system with corrosion
like water will

a Propane/Propylene mix is a bit better cooling

Thermodynamic performance analysis of eco friendly refrigerant mixtures to replace R22 used in air conditioning applications
SV Shaik, TPA Babu*- Energy Procedia, 2017 - Elsevier
In the present study theoretical thermodynamic performance of a 0.8 TR window air
conditioner with ten binary refrigerant mixtures consists of propylene (R1270) and propane
(R290) was investigated based on actual vapour compression refrigeration cycle. All the
investigated refrigerant mixtures consist of zero ozone depletion potential. Global warming
potential of R22 is 1760 whereas GWP of all the studied refrigerant mixtures were below
three and also these mixtures are closer to azeotropic containing the temperature glide*…

Are you out of your mind? Who are you expecting to appreciate this?

[nota]

an other neat idea I stumbled over

is called liquid/suction/heat/EXCHANGER

SIMPLE STUPID IDEA

JUST RUN THE COLD RETURN LINE INSIDE THE OUTGOING HOT LINE
SUCK THE LAST LITTLE BIT OF COLD ENERGY OUT OF THE RETURN LINE
TO COOL THE HOT OUTGOING HI PRESSURE SIDE A BIT AT A SMALL LODE PRICE BUT GAIN IN OVERALL COOLING FAR MORE

THEY CLAIM 20 T0 30% LESS ENERGY BY THE SIMPLE JOINED TUBES HEAT TRANSFER

[nota]

Originally Posted by Bob Kontak

Are you out of your mind? Who are you expecting to appreciate this?

NOT YOU i GUESS

[Arizona_928]

Originally Posted by Bob Kontak

Are you out of your mind? Who are you expecting to appreciate this?

Copy and paste....

But no one cares bc it's not an expensive engineered fix.