Propane V R22

Discussion in 'All Things Boats & Boating' started by Frosty, May 14, 2012.

  1. Frosty

    Frosty Previous Member

    Has any one used propane in air con system instead of R22 R21 or 135a etc?
     
  2. Frosty

    Frosty Previous Member

  3. jehardiman
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    jehardiman Senior Member

    I've heard of old ammonia plants, which were deadly enough, but a leak in a propane system? What I do know is many refrigerants are excluded commericaly because the working fluid causes bearing and seal issues which prevent retrofitting existing equipment. So we are stuck with some things until the end of thier useful life.
     
  4. Frosty

    Frosty Previous Member

    Propane has an odour and can be smelled. Propane is no more flamable than R12 /R22 infact not flamable at all until mixed with air. The oil in the compressor is more flamable.

    At 250 dollars for R22 and dont even ask about R134a as Dupont has the patent and has convinced the Gov to outlaw it.

    Propane is pennies. Propane is also known as R240 ( I think)
     
  5. SheetWise
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    SheetWise All Beach -- No Water.

    Have you looked at Duracool? I understand it's propane based, but formulated to protect the hardware.
     
  6. jehardiman
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    jehardiman Senior Member

    LOL....that's the issue with a small leak, I was never worried about the fluid IN the system....:D
     
  7. Frosty

    Frosty Previous Member


    No more inflammable that R12 R22.

    Propane--- LPG is a petroleum derivative = lubrication.


    R22 is 1300 times more ozone damaging that Co2 (Source internet) and propane is considerably less.

    Whilst your concern about safety is acceptable re- consider the 20 gallons of petrol under the rear seat that your kids are sitting on.

    An air con system needs 1/2 kilo and using propane needs less.

    If a air con pipe burst, total evacuation would be less than a second. Hardly time to heat let alone set fire to--- 'if' it were to be ignited.
     
  8. CDK
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    CDK retired engineer

    Propane works so well in refrigerating systems that all modern fridges use it. And of course it can also be used in A/C units.

    But there are issues.

    Modern car A/C systems are designed for use with R134a and employ Sanden compressors with variable output to minimize engine load. They need the temp/pressure characteristic of R134a and perform poorly with anything else.
    Also, you cannot use the highly contaminated bottled propane for cooking. It contains butane, pentane and other oily stuff that clogs the thermostatic valve within a few seconds. What you need is isopropane; it doesn't smell, contains no additives and is (of course) much more expensive than the ordinary stuff. In old R22 units it works at least as good as the original gas.

    Because of the small quantity compared to a fuel tank and the construction of an A/C system, fire hazard is a non-issue.
     
  9. Frosty

    Frosty Previous Member

    Whilst your points maybe valid CDK I do not know . The internet is full of guys filling 12 22 and 134 systems with propane in cars.

    The propane used is a clean propane --what that means im not sure , One site said it was not the LPG for cooking, I dont understand why as a refrigerent is simply a good releaser of heat hence its purity is again smoke and mirrors as is the Patent of Dupont to 12 22 144.

    Its said that a 1 ilb system would need just 2/3rds of that if using propane as it is better than 12.

    Just chopping and joining various fittings to get propane in the system manifold guages seems to be all thats required as long as you stay on the low side.
     
  10. CDK
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    CDK retired engineer

    In Europe you cannot buy clean propane, it is always mixed with other gases the refinery want to get rid of. That is generally not a problem because they all burn very well, except that butane boils at approx. 0 C. so in cold weather it has no pressure.
    Propane boils around -40 C. which makes it an ideal refrigerant.

    If you have an old A/C unit with a Delco or equivalent compressor you can fill it with clean propane and it will perform better than new.
    Filling is done on the low pressure side after the system has been evacuated with a vacuum pump for at least 15 minutes to remove any trace of moisture.
     
  11. Frosty

    Frosty Previous Member

    Yes yes I know that bit. The one in the boat is R22 and a bit down so Im thinking of filling it --topping it up with LPG from the cooking gas bottle.

    I was surprised to see how well known it is and how succesful it is and that apart from regulated USA a lot of people are doing it.

    You don't need to evacuate for a top up. If you had moisture the TX valve would freeze.
     
  12. jehardiman
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    jehardiman Senior Member

    ??

    R12 and R134a are not combustable though they will give off toxic gases if heated well above normal temp (+250C).
    http://www.inchem.org/documents/icsc/icsc/eics0048.htm
    http://www.inchem.org/documents/icsc/icsc/eics1281.htm

    and R22 only ignites at high tempertures (+600C).
    http://www.inchem.org/documents/icsc/icsc/eics0049.htm

    This is why they were initialy used, they were about as safe as you could get and thier biggest hazzard was asphyxiation in closed spaces because they are heavier than air.
     
    Last edited: May 15, 2012
  13. DCockey
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    DCockey Senior Member

    My recollection is that twenty five years ago propane was briefly considered by automobile manufactuers as a replacement for R12 in automobiles, but that the potential liability from a flamable gas under pressure with a direct path to the passenger compartment in the event of an evaporator leak was considered unacceptable.

    Individuals may reach a different conclusion for their own applications.
     
  14. Frosty

    Frosty Previous Member

    Im sure from all the information on the internet that propane will work. I agree with CDK also as well as the internet that the small amount of Propane needed 475Gms makes the inflammable thing of no issue. Like I say--your kids are sitting on a fuel tank of 20 galls of Petroleum fuel or more. Half kilo of propane behind the ventilated fire wall of the cars engine compartment would not worry me.

    My only concern is that the propane is of the cooking gas type cheaply available from any LPG supplier. Im also concerned though not as much about the smell addative that is unpleasant to say the least.

    However after checking on the ease of availability of 12 -22 and 134 plus 404 is easy here and a can of 22 is 30 dollars and I bought some manifold guages yesterday for 15 dollars at a huge air con shop in Hat yai south Thailand. They also sold 22 at 3 dollars a kilo if you had a can to pressurise it in.

    I love this freedom.
     

  15. DCockey
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    DCockey Senior Member

    The refrigerant in an automotive AC system is not isoloated in the engine compartment. It runs through the evaporator which is located in the airflow going through the passenger compartment. So the concern is a leak in the evaporator will introduce refrigerant into the passenger compartment.
     
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