Convert Cold Machine to Hydrocarbons

[rbk]

In a unique situation where I cannot get 134 to recharge my system (failed Schrader) but have plenty of access to Hc alternatives Redtek, duracool etc. I don’t want to start an argument about the explosive powers of 5.5 oz of Hc on a boat, or the processes involved, but to any Canadians or Europeans that have made the switch, was the performance as good as ‘they’ claim? How long ago did you do the swap and any side effects.

[rbk]

Ya I wouldn’t be blending it. Evac and replace with straight durracool was my thought. Company claims it’s a 134 replacement. Just looking for first hand experience, more so in a small precise refrigerant unit like the AB rather than auto AC.

I should add that the company literature for duracool and many others make some promising claims with zero pitfalls. This makes me suspicious.

[RaymondR]

Hi rbk and Ozypete.

I changed over to a hydrocarbon based refrigerant called Hychill-30 about nine months ago and have not yet blown myself up and the fridge appears to work just as well as it did with the R134. I crawl into the space where the condensing unit is installed occasionally and feel the filter drier but so far nothing to indicate that there has been any deterioration of the lube oil.

Danfoss had a 12/24 V compressor specified for hydrocarbon refrigerants but I dunno if the design differences was for the compressor mechanicals or for the electricals.

[rbk]

Thanks Raymond. Maybe it is all they say it is. Only time will tell if it has any effect on the compressor.

[Joyful Noise]

I rarely use the 40+ year old Crosley refrigeration pump on my boat but when I did it worked quite well. I assume that it was R12 and I don't know what to do about servicing it given the gasses that are now available. Any suggestions?

[RaymondR]

The two primary considerations in deciding to switch to hydrocarbon refrigerant were the safety and oil compatibility issues.

The safety issue is the possibility and probability of sufficient hydrocarbon gas escaping from the refrigeration circuit to form an explosive gas air mixture and be exposed to an ignition source. My rationalization of this factor was that I already have a large hydrocarbon gas reservoir connected to an open ended comparitively low pressure rated conduit into the boat in my gas stove and therefore the risk introduced by the 100 or so grams of hydrocarbon gas in the refrigeration circuit was comparatively very small.

The oil deterioration issue I rationalized by researching the major use of hydrocarbon based refrigerants and found they were common in large industrial systems and in Europe in small domestic refrigeration systems. Consequently I accepted the manufacturers claims that hydrocarbon refrigerants were compatible with both the old hydrocarbon based oils and the modern synthetic oils. I am assuming that any problems with the lube oil will express by blocking of the filter drier hence the regular checks for pressure drop.

Life, in respect of refrigeration problems, has certainly become a lot simpler since I changed over to the hydrocarbon based refrigerants. The product I use is available from auto parts stores and no licensing is required for it's purchase and use. I keep a can and a charging hose set on the boat and when I notice a lessening of the most downstream evaporator plate give it a little shot of gas and things go back to normal.

[sdowney717]

I did this on an R22 system and it works fine.
The propane you want is simply the kind in the small torch bottles, its dry and clean enough to work.
Charge amount is about 50% of the amount of R22.
If you look at the comparison PT chart for R22 and R290, (propane), they are about identical.
And the EPA has ruled Propane can be vented to atmosphere.

Things are heading to propane as it has a global warming number of 3 versus many thousands for most all other refrigerants.

Charge to 70 to 75 psi low side, and charge by superheat of 10 to 16*F, and it works.
And the other good thing about using it is its cheap and does not cause environmental concerns. At least the marine AC units have a high pressure cut off switch. Many of the new refrigerants are also explosive. I am glad they have not banned r134a yet.

[OzePete]

Some great info here and would be good if those members who do try a conversion to one of the blends could keep us informed with the results.

Cheers OzePete

[Grattaway]

OsePete

In an emergency most refrigerant blends will do the job. I operate a coldstore here in NZ and have used a number of different ones including Hc. We did not experience any compressor issues when changing from R12 or R22 or R404a to Hychill -30
Hc is more efficient than R134a or R22 and see previous replies regarding quantities.

R134a is generally widely available as most vehicle aircon units and most shipping containers are still charged with R134a but in a pinch most alternative refrigerants will keep a system operating without to many issues.
If I had to change om my boat in an emergency a propane mix (In Aust Hychill) would be my choice given that I already have propane gas and a gas detector on board so minimal safety issues