r-12 to ?

[garthr]

have an old milk truck with a separate fridge and freezer. apparently has a low charge, been sitting for 12 years. question. can i evacuate and replace with r-134a? being a refer dumb-dumb would anyone know if this makes sense?

[monkey spanners]

Hi Garthr,

R134a won't be compatable with the oil and o rings used in your old system. What you need is a refrigerant designed to replace R12 in existing systems such as R413A also know as R49 or I believe there is one called 'hotshot' in the states. Have a talk with your local rerigerant wholesaler to see what they stock and recommend.

Jon

[garthr]

thanks for the reply. i have heard of a replacement refrigerant for r-12 called freeze 12 for automotive use. would this perhaps be a satisfactory substitute for r-12 without component damage and without having to change the oil??

[monkey spanners]

I've not heard of freeze 12, personally i wouldn't use any refrigerant that didn't have an 'R' number.
What R12 replacements does your local fridge wholesaler stock?

Just had a quick look online, RS24 or R426A might be worth a look, all the other blends listed in the US EPA list seem to still hcfc's in them, which are being banned here in december, not sure how far behind things are in the States.

[Petur]

i have been asked to replace r12, normally that is 134a and change of oil etc.

but if i want to retain the plant as is, what refrigerant can be suggested

bstrgds

[chemi-cool]

R-409 is a replace for R-12.

I have used it a lot and it is doing very good job.

You work above 0°C so you will not have any problems.

[mikrasiates]

R409 my friend it is good

[paul thompson]

use r 49+ , EASYstraight foward , no messing about with oil change . just recover any existing refrigerant , change drier , pressure test . vac out system if pressure test passes , and recharge .we ,ve done 100,s on r49 and now on r49+ .