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Hello all,
Just lately I seem to be coming across more and more units that have had r134a removed and replaced with gasses like 'care 30'.
Surely unless the electrics are sealed ( made spark proof) it can't be very safe, because all it takes is a leak to mix with air and it could cause a small explosion.
I haven't had any experience in handling flammable HFC's so could someone correct me if I'm wrong.
Thanks Neil
the chances of it igniting is really remote..i guess we all remember that infamous case in australia with the behind bar cooler blowing up
however you probably have a 1 1/2 gas main coming right into your home -so how much sleep have you lost over it?
they (care) had to be extra cautious at the outset but like most 'dangers' familiarity breeds contempt -but you should also remain vigilant
cheers
richard
Hi Neil,
I dont know about EXPLOSIVE but with large amount in a small closed space and you cant help the urge for a cigarette. You are in danger.
care 30 like R600 is used more and in small domestic apliances.
The amounts is usually small and if you follow the safety guidlines made by the manufacturer, you are on the safe side.
I have only once in my life seen someone gets killed from having a leak in the oxygen hose next to a running 1/4 hp compressor which was "sucking" the oxygen in and after a few seconds: - oil and oxygen have been mixing and.......BOOOM.
Do you use the torch on a compressor charged with oil?
Now you can work the odds out yourself.
Have a Marry Christmas.
Chemi
Hello All,
I once saw a photo of a reciever that looked like it had be opened with a tin open except that what had happened was an untrained engineer pressure testing with oxygen not OFN.
At the end of the day, common sense prevails. If you go by the book then you shouldn't even use you're mobile phone near a CARE charged unit in case the static sets it off (Much the same as using you're phone in a petrol station).
Eliminate all possible risks and nothing SHOULD !!! go wrong
in a system that was evacuated right? there would not be enough oxygen in the system to allow it to ignite i wouldn't think.
also, the gas in the system is surposed to be relative to the size of the room where the appliance/system is installed, which is not supposed to displace anymore then 10 or 12% of the oxygen in the room or allow an ignitable amount out should all the gas escape and stay in the room.
which i think will work great.... until retailers get into it and sell thousands of these things (as appliances) without asking questions. i went to a guys place yesturday and he had 4 350L fridge freezers in a bedroom ... a potential bomb i suppose if something 'should happen'.
has anyone here got much experience working with and installing systems that run on hydrocaron refrigerans? i heard they only need about 1/3 the amount of gas that an equivalent ***** system does. true/false?
The HC refrigerant charge is also typically only 40% of the HFC equivalent.
lifted from their site
http://www.care-refrigerants.co.uk/h...id=3&idofuser=
cheers
richard
Let's me think on a accident of a colleague of my, years ago who lost his hand. He had oiled the thread on the oxygen pressure regulator and as soon he opened te oxygen, the regulator exploded, happily not for him the whole oxygen bottle.Quote:
Originally posted by chemi-cool
Hi Neil,
I have only once in my life seen someone gets killed from having a leak in the oxygen hose next to a running 1/4 hp compressor which was "sucking" the oxygen in and after a few seconds: - oil and oxygen have been mixing and.......BOOOM.
Do you use the torch on a compressor charged with oil?
Many of the fuels will not ignite at percentages over 15%
When you think about that, you have to have 85% air in the system which would not really happen very often.
There is also several things done inside a compressor to prevent spark potential, not just on systems using flamable refrigerants either. The sparks would lead to oil failure as it is not designed to be at those temperatures and it would degrade fast. This is why sleeve bearings instead of ball bearnings are used. It is why a centrifugal switch can not be used for starting components.
ASHRAE resomends not to use the straight hydrocarbons because of the risk that still exist, but also notes that improved oil return in low temp systems has advantages and makes them the refrigerant of choice.
Hi:)
just to note, these care refrigerants have flame retardants in them that brings the ignition temperature up quite a bit.
Me I would love to work on large hydrocarbon jobs (have I got a death wish :confused: )
We will be puting in one in polypropylene shortly with a 300kg charge:D
needless to say it is on a petrolem site and it is housed outside in a shelter far away from anything:eek:
Regards. Andy:)
want a lite andy?
Andy,Quote:
Originally posted by Andy
Hi:)
We will be puting in one in polypropylene shortly with a 300kg charge:D
needless to say it is on a petrolem site and it is housed outside in a shelter far away from anything:eek:
Regards. Andy:)
Why are they using poylpropylene? I see no advantages - a lot of disadvantages- but I have almost no experience with it. Perhaps they produce the refrigerant and that's the main reason.
I used it sometimes in a cascade system (coldtrap in a Leybold vacuum machine) as the 1st stage. We later changed one machine (after a compressor burnout) by R404a with almost no major adjustments to the cooling circuit. as far as we measured, we lost no cooling capacity.
Working on that specific machine is no much easier and safer.
The fire risk of hydrocarbons is usually way overestimated. Inside the system nothing can happen; there is no oxidizing agent inside (many of you think about air/oxygen only, but chlorine would be just as good, for example).
If a leak occurs, a few things must be right for something bad to happen:
- Fuel/air concentration must be between the LEL and UEL. Which is a fairly small band for most hydrocarbons.
- An ignition must occur.
- The ignited hydrocarbon/air mixture must be able to do damage.
Within most appliances, this won't happen. Airflow though the condenser or evaporator will remove the hydrocarbon from the confined space, if there was a confined space at all.
Ignitions won't occur easily at the same time the leak occurs.
And finally, the inside of most chambers containing the refrigeration system contain self-extinguishing stuff only. Thus even when a fire occurs, it won't spread. If it explodes, the chamber usually can take the beating and it will distort badly at most.
Jus a consideration (I'm not a chemist and I never understood it in school because it is not tangible): suppose a polypropylene compressor running below atmospheric pressure, there is a leak on the LP side and air and oxygen is entering and there is a spark inside on the windings. What then? This is a hypothesical question.
When we worked on that specific machines, the factory had made special tailor made work specs which we had to follow very stringent. Otherwise we could go.
Peter
As I said, the hydrocarbon concentration must be between the lower and upper explosion limits. Which is somewhere between 8% and 20% if I recall correctly. This means that we must suck in a huge amount of air; way more than what is required to stop the device from functioning.
And of course you are given stringent work specs. Everybody is uncomfortable about hydrocarbons, and the manufacturer knows that. One single failure due to an engineer being stupid, and he never sells a single package again.
try telling that to the nsw government over here... they wont let us put it into cars for fear of starting a fire.Quote:
DaBit
The fire risk of hydrocarbons is usually way overestimated. Inside the system nothing can happen; there is no oxidizing agent inside (many of you think about air/oxygen only, but chlorine would be just as good, for example).
need i remind them how much petrol my car carries? or the amount of gas in the cylinders carried my motorist running LPG?
i surpose i would rather fall into a temporary unconcious state by being smothered with r134a and possibly run into a truck or the only tree for 100Km on the highway, then singe my eyebrows when i lite a cigarette....
Did a training course for handling and using Care refrigerants, McDonalds were "made" use them in equip at Sydney 2000 Olympics. Flammability limit 2 -10% with normal air.
Like Andy I'd like to work on a large HC plant but the harsh reality of this modern world is the almighty buck.
Commercial customers will not pay extra for the additional safety concerns related to HC refrigerants.
Old mate in Oz wasn't blown up behind a bar, he walked into a small room (closet sized with non working exhaust fan) to service a condensing unit approx 1/2 to 1hp (small!) charged with a HC by a cowboy who didn't label it. Power was supplied by an extension lead pushed through into the room, the fridgy unplugged the unit to work on it and KABOOM!!!
You wouln't think it but unit had gas leak, he introduced just the right amount of air and then provided the spark.
HC's in commercial refrig units are dangerous due to the areas in which units are placed, its usually the last thing on the consultants mind when building your avg restaurant or shop and in lots of buildings its impossible to install outdoors or too costly to run 1/4" and 1/2" pipes six floors to the roof, or install mech ventilation.
Industrial only for HC's. Domestics too, they only just blow the door open when they go up!
What I did find out aboutHC type refrigerant, is that you only need about 40% gas comparerd to hfc gasses, so for domestic and under bar cabinets the amount of gas is too minimal to do much damage anyway.
Happy New Year
Neil
Friends,
Nice conversation and interesting , HC have a flammbility level from 2 till 10% by weight in air. So if you use HCs like Care 30 make sure your confined space (eg room is proportional to the refrigerant charge.) In Australia we recommend 1/3 of the original refrigerant charge in weight. ( because of the differnce in density [ try to lift a large barbeque bottle and compare it wit a similar R22 bottle you will feel the differce.]). The volume circulated in the system is the same as halocarbons.
For a "Boom or Bang"" you need a spark, right amount of HC in air, and a leak. If you add these 3 up some people who do Riskassesment come to the conclusion eg that having a "boom in car AC you need to win the Lotto twice in a row. And that is difficult or otherway being strikken by lightning twice in you life before you have a non fatal problem with HCs in your car AC system.
Does it make sence ?? All the frieightning idea's about HCs are
a continual trial by "Chemicalia" to not use HC because they cannot make money out of them, they are supplied by the LPG blokes.
jg/oz
NB we always work within the limits( lower than after full leakage of 25%) of LEL levels. EG 25% LEL level with HCs is 8 gram per m3 space. If you used it for AC system eg split in a 4x4x3m room ( 48 m3 space ) 48 x 8 gram can be used as the charge of HCs or 384 gram which is than equivalent to 348 x 3= 1 kg of Halocarbon R22 which is exactly eg a 1 1/2 hp unit ( split) so not a problem at all, you might full the room with 48 x 32 gram HC=
1.5 kg of HCs and light a match and the stuff will not ignate.
This 1.5 kg HC is equivalent to 4.5 kg Halocarbons. We use a safety factor of 1/4 of the LEL level for all cicumstances. So
safet first.
jg./oz
Hollywood has a lot to answer for.
My father in law used to be an explosives inspector. He was often called to do demonstrations, like blowing up cars at airports when an exercise was being carried out. He always had to take cans of petrol since if he just blew up the car with dynamite, everyone felt cheated. He had to artificially create a fireball.
Years ago, Australia changed the firearms laws and semi-automatic rifles had to be surrendered. I had a M1 carbine and several hundred rounds of ammo to get rid of, as did several friends. We drove to a friends farm who had a rubbish dump cut into the side of a hill. Someone brought along some old butane gas canisters (camping sort) and the farmer donated a gerry can of petrol. We soon discovered that Hollywood has been faking it. Even a plastic bottle of petrol sitting in a fire didn't do much when hit with a 22. It took a hot loaded 45/70 hitting the bottle to make something worth filming. Even the combination of butane cylinders, fire and bullets wasn't impressive.
Flammable liquids and gases need to be treated with respect. There have been too many deaths due to leaking gas to not take them seriously. But I get annoyed when people accept cars where each gallon of petrol equals several sticks of dynamite in potential explosive power, but want completely different standards for HC refrigerants.
hehe, gotta love those holywood blockbusters.
someone told me that diesel doesn't explode, anyone tryed? (that is diesel by itself ...) if so all the movies that show trucks having a head on with massive explosions are a crock...
i have tryed the flicking a ciggy but into petrol... and alcohol... it did nothing either, exept put it out, so i tryed again and again to the same avail... so Demolition Man is a crock too... only an open flame will ignite it... so smoke easy, but ignite from a safe distance lol.
of course if you actually watch these 'blockbusters' you will see the car/truck 'explode' usually 3 times from different angles in quick sequence
(just to make sure you got the idea that it has just blown up)
cheers
richard
of course if you watch these kind of film then expect to be treated with contempt you deserve
Friends,
"HC" are an interesting subject in the refrigeration world with Techies. Yes it explodes if your an idiot and using it.
Just remember the approx 2 billion housewifes in the world untrained an trying to ignite the stuff 10 times a day ????
We in Aussi land have a lot of 'silverfish' and other insects which we eradicate with so called "' ****rooch bombs" approx 300 grams of HC with some insecticide. We place this in a closed room and let the HC escape and hope for the best.
Of Course nobody read the instructions ( as useall) and sometimes we have a big explosion somewhere in Aussiland.
Nobody is killed so far but it is freightning what can happen.
It's not forbidden for untrained mothers to use this stuff, so what about HC's in Refrigeration with highly skilled Techies.
What about the 110 million EU fridges and freezers running is
on HC's
anyone an answer, let's discuss.
jg/oz
friends,
Answer to Andy--
your remarks are B.Sh. there are no flame retardents used and this was all a hoax, in Aussi land with HC use a stench is necessary in the fluids used similar to LPG ( same smell)AS/NZ 1677.part 2.
After 2. million user years I can tell you that mercaptain does not harm the "inners" of a refrigeration system nor compressors. 6 million car compressors use the refrigerant stench in HCs worldwide.
jg/oz
[QUOTE=Andy]Hi:)
just to note, these care refrigerants have flame retardants in them that brings the ignition temperature up quite a bit.
jg/oz
try www.care-refrigerants.co.uk
you never know you might learn something :eek:
Andy
Dear Andy,
I have known Calor for ages and even instructed approx
600 tech's in Calors Safety Instruction days in Australia.
I am familiar with Daniel Colbourne's and Ritters papers,
but think you should do some investigation in to Oztech US website and find out that the "flame retardent" issue was a hoax and after 1995/6 was never used again because it was
not true. Ple read an article by the Qld Gasexaminer who had the fluids tested by a laboratory and found out there was no
higher ignitionpoint in OzTech's refrigerants compared to
Propane.
Hope this helps, anyway Andy you probably did not know about this and I do not blame you for that,
best regards and no hard feelings
jg/oz
midwinter australia and 25 degr C ( on the Sunshine Coast)
Hi Guys,
I am told that here in the UK you SHOULD :rolleyes: have a certificate that allows you to purchase CARE gases and unless you have it HRP/NRS ect shouldn't :rolleyes: sell it to you is this correct.
If it is then would it not be a good idea to also bring a law in to effect ith all gasses, then hopefully it would stop untrained engineers who havn't done gas handleing getting there hands on it.
I know that people will always find a way to get some (Ebay) :rolleyes: but it's a start.
I am due to go on a CARE course in the next few weeks as apparently a lot of ice machines are now using it. Anyone else done one, if so was it usefull, i will post about it once i get back.
Regards
Raymond
Friends,
in Austrlaia we have regulation with Care products that a
Safety Certificate from Elgas ( local supplier) was required to be able to buy the LP Refrigerant gas.We in Aussi-land need to have a CFC Licence to buy ODP and GW refrigerants.
An interesting seminar was held by MacDonald, Ice Cream
supplier Unilever and Coca Cola. Basically these companies confirmed their abstance of "HFC" in the near future and go over to None HFC equipment.
have a look at http://www.refrigerantsnaturally.com
go into eg presentations and try to download he various
presented papers, very intersting and a lot of you making a living out of Factory "made plug in" refrigeration equipment may in for new study to follow Hydrocarbon, CO2 and other new
technologies which you may need within a few years, those who are early educated probably are on their way to become future millionaires.
good luck to you all
jg/oz
Propane as refrigerant is as safe as any other gas appliance or machine. I was in IIAR 2003 where the McDonald's restaurants using propane as refrigerant were presented by DTU (already operating in Denmark). If all these toxic and explosive substances were used 100 years ago, I thick with modern tech we can do fairly better!
BTW, answering a previous question, diesel does not ignite at atmospheric pressure. It has to be compressed to explode.
-Manuel.
I am due to go on a CARE course in the next few weeks as apparently a lot of ice machines are now using it. Anyone else done one, if so was it usefull, i will post about it once i get back.
Regards
Raymond[/QUOTE]
i did mine back in '99 -got it because the company we subbed to got the sydney games contract to supply 2 million quids worth of catering equipment.
i was hoping to go there as 'resident' fridge guy for the duration.
sadly they got some local in...750 valve
was it useful..not really haven't seen much color stuff and i don't 'do' domestics
cheers
richard
Hello everybody discussing this subject about flammable refrigerants.
I am the person responsible for the Danfoss controls for HC refrigerants, and I would like to inform you about our policy for these products.
The main reason for developing the HC program was because HCF would be phased out in Denmark (we got a new government, so we still can use HFC, but with limitation in charges to max 10kg per system).
Untill Danfoss decided to enter the field for larger systems we only supplied compressors to domestic refrigerators and freezer with up to 150 grams as max HC charge.
So the Danfoss policy was changes so we could deliver controls for systems with larger charges.
However Danfoss did want to end in a court case in countries where the law and legislations are not know or is known to be unacceptable.
So the controls can be supplied in EU and EFTA areas only.
Before we will supply there has to be a signed agreemnt between the user and Danfoss, it means, no agreement no supplies.
The rerfrigerant selected are R-290, R-1270, R-600 and R-600a for commercial refrigeration.
These products are classified for Hazard Zone 2 (only rare or short term threat), this according to the ATEX Directive (94/9/EC) and the Pressure Equipment Directive (PED) (97/23/EC).
I highly recommend that you follow the above Directives and any local legislation in the country operate in when you work with flammable refrigerant.
Getting informations about the products will always be through the local Danfoss sales company.
There was also the question why using R-1270 Propylene. The best reason I know is the compressor can in most cases be one size smaller compared to use R-290 Propane.
Regards Jorgen Bargsteen Moller