View Full Version : How do you identify the refrigerant type in an unmarked system?

20-03-2014, 02:33 AM
Hey guys,

I have taken over an old ***** plant that has 11 separate systems. There are 3 different refrigerant types scribbled on the walls. I need to add gas but obviously want to add the right type. Does anybody have any cheap tricks to determining the refrigerant type within a system when there is no identification present.

20-03-2014, 03:51 AM
Pt chart works for me

20-03-2014, 04:52 AM
each gas has own pressure in different temperature.
So you can read pressure of system (evaporator )when it is off and read temperature of that and then look to all gas charts and you can find it is mach with one of them (you should have good gauges and good thermometer
R 22 -10.2 == 3.6 bar
R 134a +5.5 == 3.6 bar
R 404A -16.1== 3.6 bar
also R12 and R502 and R503
normally :
R12 for above 0 c
R22 for -20 to 0c
R 502 for low temp -20
R 503 for very low temp
Also you can find on top of expansion valve type of gas in system and each gas has standard color and you could see this color on top of expansion valve .

20-03-2014, 07:50 AM
Client might have old service reports to help if other suggestions exausted

20-03-2014, 09:39 AM
A Flame leak detector will tell you if it is HCFC, ie R22 as it will turn green, if it dosen't it likely a HFC. Just be careful though if it HC if may go bang!:eek:

20-03-2014, 04:05 PM
Android devices
https://play.google.com/store/apps/details?id=com.danfoss.koolapp (https://play.google.com/store/apps/details?id=com.danfoss.koolapp)

Edit - above link is to Danfoss PP app, Brian_UK

21-03-2014, 12:41 AM
you should be look label of TEV to exactly

21-03-2014, 02:21 AM
That's not so,seen plants with no markings on valves,sticker missing corrosion and 404a plant running with r22 valves,pt chart as I said earlier refrigerant type written on wall!!! Are correct marking label's/ tags hard to locate in your locality? Sounds to me like you need to identify the gas in all that and label it correctly,oh and paint/remove the writing on the wall and have a log/ record book in both the main office and plant room cannot believe it's not a legal requirement where the equipment is located.

The MG Pony
21-03-2014, 02:56 AM
the pt will get you close, but not exactly. In my books two options exist, take a sample and have it anylized, round about way but guarantees results.

that would be my first choice. Failing this, I would recover full charge, try to determine oil type, then recharge with the closest matching gas for the valves and oil, but even this is a shot in the dark.

The clues if present will be the compressor, txv and the temp range of the plant, but with out analysis it is all a blind shot short of a rebuild!

failing all ells take the pt and cross ref with the compressor markings if possible txv, in the very least the new gas will be close enough that the system will still sort of function!

21-03-2014, 06:27 AM
And all because some Muppets did not label it up correctly,so Mark plant up people!!!!

21-03-2014, 07:49 AM
What are the 3 refrigerants written on the wall?

21-03-2014, 07:57 AM
A Flame leak detector will tell you if it is HCFC, ie R22 as it will turn green, if it dosen't it likely a HFC. Just be careful though if it HC if may go bang!:eek:

Ahhh, the good old days of detecting gas leaks on CFC plants. :(

21-03-2014, 07:16 PM
pt chart will be accurate enough to determine what refrigerant each system is set up for. If your pressure and temps come out correct for R22 for example then it's pretty safe to say that's what the system has run on but you may well have a drop in refrigerant in there now which will have similar pressure and temp ratio. Now might be a good time to get your flame leak detector out to narrow it down. If you know you need R22 running pressures but your not completely sure what's in there, reclaim and charge with with a drop in, Then scribble on the wall... I mean LABEL it!

21-03-2014, 07:18 PM
What are the 3 refrigerants written on the wall?

Isn't that a nursery rhyme?..... Oh no I'm thinking of green bottles......

monkey spanners
21-03-2014, 11:45 PM
Remove the refrigerant and start again with your preferred type for the application. Or just top it up with your preferred type :D

22-03-2014, 05:47 PM
The 3 refrigerant types are R22, R404a & R507

Thanks for all the advice. I was able to recover some old service reports. I have already gone around and labelled all the units.

The MG Pony
23-03-2014, 11:24 PM
good show!

25-03-2014, 03:12 AM
brilliant wish everyone would do the same,it makes it so much easier for everyone.

install monkey
14-04-2014, 08:13 PM
analize it;)