HR12 gas for A/C
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  1. #1
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    Default HR12 gas for A/C

    Hi,
    i'm hoping for superior knowledge on A/C gases etc.
    Just discovered HR12 available in 300g cans. It is hydrocarbon and it's makers claim great performance. www.hychill.com
    As i've invested in a set of gauges and hoses and being fedup with the time and money it takes for shops to regas with not always good results i decided to have a go. If there is a leakage i can replace o-rings etc in my own time.
    For evacuating the system i use a fridge compressor in reverse. It pulls 30 inHG in Melbourne (Surrey Hills). For weighing the gas i use digital kitchen scales ($65).
    In the last two days i 'did' my daughters 84 Pulsar and it cools to 8 deg C. at 20 deg C. ambient. My other daughter's Suzuki 998cc (yeah, i know it is a lawn mower motor but the thing is surprisingly good around town) after replacing all the O - rings, evacuating and recharging i have a high low side (between 80 and 110 psi) and a low high side reading not much higher.
    The puzzling thing (to me) is that this indicates a compressor problem/low side obstruction. Yet, the vent temp. is cycling between 2.2 and 4.6 deg C.
    So, it works, but there is a problem.
    I'll get to the 19's soon. One was converted to R134a but i'm not sure it was done properly (not just fittin a 134a fittin on the low side and gassing it up. It only cools to 11 deg. C. at 25 deg. C. ambient.
    Any ideas would be very much appreciated.
    JoBo

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  2. #2
    1000+ Posts robmac's Avatar
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    Default hr 12 /er12

    Quote Originally Posted by JoBo
    Hi,
    i'm hoping for superior knowledge on A/C gases etc.
    Just discovered HR12 available in 300g cans. It is hydrocarbon and it's makers claim great performance. www.hychill.com
    As i've invested in a set of gauges and hoses and being fedup with the time and money it takes for shops to regas with not always good results i decided to have a go. If there is a leakage i can replace o-rings etc in my own time.
    For evacuating the system i use a fridge compressor in reverse. It pulls 30 inHG in Melbourne (Surrey Hills). For weighing the gas i use digital kitchen scales ($65).
    In the last two days i 'did' my daughters 84 Pulsar and it cools to 8 deg C. at 20 deg C. ambient. My other daughter's Suzuki 998cc (yeah, i know it is a lawn mower motor but the thing is surprisingly good around town) after replacing all the O - rings, evacuating and recharging i have a high low side (between 80 and 110 psi) and a low high side reading not much higher.
    The puzzling thing (to me) is that this indicates a compressor problem/low side obstruction. Yet, the vent temp. is cycling between 2.2 and 4.6 deg C.
    So, it works, but there is a problem.
    I'll get to the 19's soon. One was converted to R134a but i'm not sure it was done properly (not just fittin a 134a fittin on the low side and gassing it up. It only cools to 11 deg. C. at 25 deg. C. ambient.
    Any ideas would be very much appreciated.
    JoBo


    If you are gettiing what appear to strange pressures where are the service ports ?, if they are not on the compressor then readings may be different.

    Watch HR 12 when you use it -it like LPG - not dangerous it you are aware that it is flammable.

    It is also not miscible with other refrigerants so start with an empty system.
    Replace the receiver and give it a good long vac down.

    I was told the story about a techi who tried to free a rusted receiver dryer fitting with oxy torch, ruptured the o ring ad had a flame out with the refrigerant. Watch the ionisation and flame leak testers !!!
    Dont use them!!

    You can't use the old trick of the lack of bubbles in in the sight glass to confirm a full charge as you could with R12. Low side is also not really good check of charge. HR 12 always foams.

    The way it is done is weigh the charge , usually abour 600gm (from memory) for the average system.

    If you are going from a r12 system and using hr12, the you will have slightly too small condenser , it works at a higher high side pressure. Make sure the condenser is absolutely clear and add / fit a bigger fan to it. R 134a is even higher condensening pressure, so you can put straight into a r134a system (check oil compatbily)

    You get about 25 degrees c temperature drop across coil when
    all is working 100 %. , but that is seldom acheived in my experience. 2 to 4 discharge air is excellent

    Incidently you are supposed to have a refrigerant handlers certificate and not allowed to vent R12 to the atmosphere.

    Of course the systems you work on are totally empty before you start so that's no problem.

    regards

  3. #3
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    Hi robmac, thank you for the info.
    the service ports i usesed are after the r/d on the high side and the low side is on the way to the compressor.
    The system was out of gas and i vacced it for 1 hr. Don't have any leak dedectror except soapy water. But i vacced for 5 min. and observed the vac gauge for another 5 to 10 min. for leaks,
    The weight of the charge is supposed to be 1/3 of 134a. I put 210g onto the Suzuki. The R19 will take 270g.
    I'm aware that it is flamable as is the petrol in my tank (about 40 to 50l)
    HR12 is alleged to run at lower pressure than 134a.
    I'm crafing info re A/C, so i hope to receive more.
    Thank you

    JoBo

    P.S. should be craving before edge gets on his high horse
    Last edited by JoBo; 6th February 2005 at 06:33 PM.

  4. #4
    1000+ Posts robmac's Avatar
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    Default Aircon Info

    Quote Originally Posted by JoBo
    Hi robmac, thank you for the info.
    the service ports i usesed are after the r/d on the high side and the low side is on the way to the compressor.
    The system was out of gas and i vacced it for 1 hr. Don't have any leak dedectror except soapy water. But i vacced for 5 min. and observed the vac gauge for another 5 to 10 min. for leaks,
    The weight of the charge is supposed to be 1/3 of 134a. I put 210g onto the Suzuki. The R19 will take 270g.
    I'm aware that it is flamable as is the petrol in my tank (about 40 to 50l)
    HR12 is alleged to run at lower pressure than 134a.
    I'm crafing info re A/C, so i hope to receive more.
    Thank you

    JoBo

    P.S. should be craving before edge gets on his high horse
    Hi Bo,

    If you get a pressure rise after shutting off the vac to the system it doesn't necessarily mean there are system leaks.

    If the system has been open or "wet" it can be moisture coming out of the oil
    and reducing the vacuum. In gauge rise fact it is the standard way of checking fo this.

    BTW on systems which are suspect moist do your first vac, break the vac with refrigerant to about +2 psi . Leave for a few minutes. Let the charge out till the pressure is only very slightly positive. You can do a prelim leak test at this stage and not waste a full charge if there is a leak. Then vac the system again.

    The refrigerant attracts and absorbs residual moisture in the oil and the second vaccing clears it out. You get a cleaner system this way.

    I always do this this on split systems where the piping may be moist, before I open up the condensensing unit (which is pre charged).

    If you can find an old "open" (the one used on old display freezers) refrigeration type compressor, the type with reed vales, they work well as vacuum pumps. Eventually your hermetic compressor will fail because it is not being properly lubricated at the moment.

    regards

    Rob

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    Thanks a lot Rob,
    you've told me a lot i did not know. Was wondering about the fridge for evacuating, I thought if i give it a bit of oil prior it would be OK?
    Any ideas on flushing the system? Melbourne Auto Air have a 4l or 5 l can for $80.-. My mate's garage - the boss told him to use metho to flush the system.
    Another point is the receiver dryer. when and how often should it be changed and how do you know when it needs changing?
    Hope to get an answer
    thanks and regards

    JoBo

  6. #6
    1000+ Posts robmac's Avatar
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    Default Purging/ Flushing System

    Quote Originally Posted by JoBo
    Thanks a lot Rob,
    you've told me a lot i did not know. Was wondering about the fridge for evacuating, I thought if i give it a bit of oil prior it would be OK?
    Any ideas on flushing the system? Melbourne Auto Air have a 4l or 5 l can for $80.-. My mate's garage - the boss told him to use metho to flush the system.
    Another point is the receiver dryer. when and how often should it be changed and how do you know when it needs changing?
    Hope to get an answer
    thanks and regards

    JoBo

    Hi Jobo,

    The standard flushing medium is R11 which is simliar to carbon tet a highly volatile liquid. Bought in tins. -keep them capped !!!

    You buy R11 at refrigation supply shops.

    Use compressed air to force it through the components after system pulling all the lines off. If you are a purist you will use compressed dry niitrogen to do this instead of air, but I wouldn't worry -you will vac the system afterwards.

    I would not use metho because of the residue which can gum up tx valves.

    Reciever dryers have a mesh filter and a dessicant in them to dry up any moisture you miss whilst vaccing. The book says change them every time you
    do major service.

    I suggest you replace every time you find that has zero pressure and therefore a leak and has the system has probably gone atmospheric.

    Or if a compressor fails and fills the system full of sh*t.

    BTW you know about liquid slugs when charging don't you?

    Charge thru the hi side initially when the system stopped.

    Run the system and to trim the charge you can introduce gas thru the low - note gas, not liquid make sure the cylinder is right was up, atch the gauge and using the hand valve keep the pressure under 50 psi. This is necessary when doing top ups.

    It you get a liquid slug you can destroy a compressor valve. If you have short hoses on your manifold gauges this is real risk. If they are long then the liquid tends to evaporate.


    regards


    Rob

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    Default

    Thanks again Rob,
    did not know about liquid slugs.
    I've studied the 134a book from Melbourne Auto Air but don't recall anything about that nor about putting charge in on the high side (with the system not running of course). Also what is the duration of a good vac. Shops only do it for 30 to 45min.?

    Thanks, Jo

  8. #8
    1000+ Posts robmac's Avatar
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    Default Vaccing

    Quote Originally Posted by JoBo
    Thanks again Rob,
    did not know about liquid slugs.
    I've studied the 134a book from Melbourne Auto Air but don't recall anything about that nor about putting charge in on the high side (with the system not running of course). Also what is the duration of a good vac. Shops only do it for 30 to 45min.?

    Thanks, Jo

    Jo,

    The time you vac it for depends on the capacity of and "how deep" the vacuum pump pulls.

    How big is the compressor you are using ? If it is a 2 hp a/c compressor
    then probably 1 hr is fine. If it is a little fridge compressor then a quite a bit longer. Breaking the vac with a refrigerant helps a lot too.

    Hi side charging whilst not running is the go - the charge is circulated around the system at least once. If you charge low side the charge is sucked stairght into the system and if there is any liquid when started it hits the reed valve.

    You can drop a whole liquid charge (cylinder inverted) into the system hi side this way - it is good practice to turn the compressor with a socket a few turns just to distribute any liquid.

    The other thing 1 forgot to mention relative to measured pressures. Is that these vary wildly depending on the heat load ie how hot it in the car and the air thru the condener and ambient temperature.

    You should put a fan thru the vehicle radiator / condenser when testing.

    If you have a few vehicles to do suggest you look for an old open type fridge compressor - they make quite a good vacuum pump and have good volume.

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    Interesting stuff...

    A few years ago I had some contact with people who were trying to break into the market with an American hydrocarbon refrigerant. The garbage they were getting in opposition was unreal!

    Their fingers were burned badly, but those who had their gas in their cars and coolrooms were laughing all the way to the bank.

    The people involved reckoned the only way a hyrdrocarbon refrigerant would ever make the grade in Australia would be if it came from Du Pont. After all, it was the vested interests in the major players that caused them all their troulbes.

  10. #10
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    Default Vac pump

    Jobo

    "Somewhere" among my junk, I have an old bee-keeping refrigeration unit that many years ago I stripped off the copper tubing. If this unit is any good to you, I can hunt it out - I have your phone # from two years ago if it is still the same.

    Ken

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    Quote Originally Posted by Kenfuego
    Jobo

    "Somewhere" among my junk, I have an old bee-keeping refrigeration unit that many years ago I stripped off the copper tubing. If this unit is any good to you, I can hunt it out - I have your phone # from two years ago if it is still the same.

    Ken
    Thank you Ken,
    Very kind of you but i have a 1HP unit that works well.
    Start on the R134a converted R19 and sure enough the bugger only changed a few O rings. The ones on the R/D and a few others were still the black ones. He probably didn't even change the receiver/dryer let alon the oil.
    Speaking to someone in the industrie he said that probably 80% work like that.
    His mate uses premium unleaded for flushing a/c systems. Insists that it is an OK practice.
    Rob's info especially the finer details i found extremly helpful.

    thanks guys

    Jo

  12. #12
    1000+ Posts robmac's Avatar
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    Default Refrigerants

    Quote Originally Posted by Ray Bell
    Interesting stuff...

    A few years ago I had some contact with people who were trying to break into the market with an American hydrocarbon refrigerant. The garbage they were getting in opposition was unreal!

    Their fingers were burned badly, but those who had their gas in their cars and coolrooms were laughing all the way to the bank.

    The people involved reckoned the only way a hyrdrocarbon refrigerant would ever make the grade in Australia would be if it came from Du Pont. After all, it was the vested interests in the major players that caused them all their troulbes.

    R22 is "hydrocarbon" refriigerant. It been around since JC was a little boy.

    What is needed is an efficient refrigrant for car use. R22 only give change in temp of 20 degreesC .

    R12 (a hydrofluoruocarbon) preferred for car or low temp systems, gives about a 30 degree C change.

    ER12, evironmentally friendly R12 (and HR12) I suspect are little more than LP gas and do an inferior job to R12 but still much better that R134a .

    Yes, Du Pont traditionly hold the market share.

  13. #13
    Gone Fishin' Ray Bell's Avatar
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    This produce was, I think, HC12... and it was basically LPG with a flame retardent in it.

  14. #14
    Real cars have hydraulics DoubleChevron's Avatar
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    I used to have a crazy (but extremely inteligent) old guy living over the road from me. He swears LPG works really well in air-cons (my reply was "BANG"). He seamed to think it was quite ok though.

    This is very interesting to see that you have used an old fridge motor to vacuate the system.

    How much would did it cost to make up all the fittings. You see I'd love to fit air-con to my CX, but I simply can't afford to spend all the $$$ required to have so called "profesionals" do the work. And once you have the equipment you can then always fix your own leaks.

    seeya,
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    Hi Shane L.,
    the two gauges on a manifold and 3 hoses (only three footers) cost $132.- inl GST.(BOC).
    The fridge motor was free. I did a dismanteling job in a cafeteria. At first i wanted to sell the thing but nobody wanted it - not even the fabricators of refrigeration cabinets.
    Apart from that it is only consumables like refr. oil, rec./dryer, o - rings (about 3 to 4 for a packet of the smaller variety).
    A mate bought a complete dual system for a Tarago from Andy's in Broadmedows for $200.-. It was still gassed up so hopfully it will be ok.
    It would be a bit fiddly to fit a system that is not specifically made for the car.

    Hope it'll work for you too

    Jo

  16. #16
    1000+ Posts robmac's Avatar
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    Default tarago dual air

    Quote Originally Posted by JoBo
    Hi Shane L.,
    the two gauges on a manifold and 3 hoses (only three footers) cost $132.- inl GST.(BOC).
    The fridge motor was free. I did a dismanteling job in a cafeteria. At first i wanted to sell the thing but nobody wanted it - not even the fabricators of refrigeration cabinets.
    Apart from that it is only consumables like refr. oil, rec./dryer, o - rings (about 3 to 4 for a packet of the smaller variety).
    A mate bought a complete dual system for a Tarago from Andy's in Broadmedows for $200.-. It was still gassed up so hopfully it will be ok.
    It would be a bit fiddly to fit a system that is not specifically made for the car.

    Hope it'll work for you too

    Jo

    Hi Jo,

    The Tarago Dual air system is made by Nipponenso. Without doubt it would have to be one of the most sophisticated auto con system made.

    It has twin evaporators (and some with an ice box/drink cooler too) . It also has twin condendors, one in front of the radiator and one horizontally under the front of the car.

    There is an electronic j*sus box that does all the logic.

    It has solenoid valves on the liquid lines to the evaporators which are controlled by individual thermostats.

    In the Tarago or Spacia it is a magic system -but prone to blockages and electronic module problems.

    I dipps me hat to the person who could re-install it in another car and make it work !!!

    regards


    Robert

  17. #17
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    Hi Rob,
    you are spot on. But the system he got has all the bits you describe except the computer and it only has one temp. sensor in the front evaporator. don't think he got it working yet.
    I think the system should work ok this way.
    He looked at another Tarago and it had the works and it confused him a bit.
    If you have any pointers, i'm sure he'd appreciate them.

    Any ideas are most appreciated

    Jo

  18. #18
    1000+ Posts robmac's Avatar
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    Default Tarago Air Con

    Quote Originally Posted by JoBo
    Hi Rob,
    you are spot on. But the system he got has all the bits you describe except the computer and it only has one temp. sensor in the front evaporator. don't think he got it working yet.
    I think the system should work ok this way.
    He looked at another Tarago and it had the works and it confused him a bit.
    If you have any pointers, i'm sure he'd appreciate them.

    Any ideas are most appreciated

    Jo

    Hi Jo
    If either of you has any electronic knowledge forget about the themistor temperate control and use standard bourdon tube thermostats front and back..

    You will need to work out the logic to make the conpmressor and condensor fans and the evap solenoids operate. This is in place of the "computer" ecu as Denso call it. This can be done with few a relays to create "relay logic" in place of the ECU.

    Essentially the fans and compressor run when either thermo is under temp and the indivdual evap thermos control the individual soleniod valves. There is evap fan switching and the on/off for each front and back but this straight foward.

    I take it is the twin solenoid valve version ? In the Spacias they had a single soleniod valve version. If it only has one thermistor in the front evaorator it may be the one valve version -I have a full installation manual for one of these !

    Check whether it was out of a Tarago or Spacia the systems are very similar and pretty well interchangeable

    regards


    Rob

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