AC with Propane- Staying Alive - PeachParts Mercedes-Benz Forum

airedale2 · #30 08-12-2009, 12:44 PM

Hello everyone,

havent posted for a while. I am using hydrocarbons in my ac on my 300d. Had to play around with the pressures for a while as the pressures from the supplier do not match up correctly. With trial and error i do have a functioning ac again. I am currently using products from envirosafe as it is a purified product. BBQ propane works fine, but the added butane keeps high side pressures lower. This is the reason for the blended product.

Tried lower pressures, and they were okay for cooler temps in the 80's. Tempuratures in TX are well into the 100's for most of the summer though. I have my low side pressure up to 55psi and my high side runs between 200-250psi depending on temps. Mostly around 225psi in 100 degree days.
I get about 50-55degrees at the vent while moving.

When running the motor at about 2500-3000 rpm, the pressures drop to about 35psi, which seems to be an ideal pressure when looking at r134, r12 and propane/butane. If you are charging your system with any refrigerant, you must run your motor at operating rpms. Most use 1500rpm as a rule of thumb, but remember that 617s like to routinely operate at 3000rpm. Then you get proper cooling across the outside condensor.

I have had the pressures up to 60psi with no appeciable losses or strain on the compressor. I have noticed that compressor runs with less strain than with the previous r134 conversion. The compressor was very noisy with r134, and not a good noise. It is now very quiet and smooth with hydrocarbons.

Hydrocarbons will work with ANY oil, mineral or pag. You do not need to flush anything unless you have an obstruction.

As far as conversions go, you only need to convert your r12 system with r134 fittings and then you can run any refrigerant you want. Epa has no standing on the use of hydrocarbons. Why, because the new refrigerant of the future 410a, is half hydrocarbons. And it runs at twice the operating pressures of its predecessor r22. If you are concerned with a leak, most leaks will occur outside the cabin in the high pressure side of the ac. If inside, it would be very, very minor and neglible.

So if i am correct, then it will be okay to use hydrocarbons in your house but not in a vehicle? Someone is going to make a lot of money off you naysayers. And thats okay. I just want to leave you my card when you call.

I am a fireman(that actually goes into actual burning buildings) and now i also have my ac certification soon to finish my assoc. in residential cooling. Looking from both ends of the spectrum, get used to hydrocarbons, because they are here to stay and will become the future.

By the way, r134 is on its way to being phased out along with r22. Then what are you going to use in your ac?

If anyone has any questions regarding charging their auto ac, feel free to contact me, i would be happy to help. Just remember, i assume no responsibility for what happens, including frostbite.