Quote:
Originally Posted by RB855
In my hurry to reply before bed, I forgot to explain some of the bigger deciding factors of choosing r-134a. Using a constant of 54* evaporating, 150* condensing temperatures.
R-410a pressures would have been pretty extreme, 155/610psi. R-22 a bit more acceptable 90/370, but not oil compatible. R-290 was considered for some time, given 85/327, but seeing as r-134a was 51/260 which are much more manageable, and available in bulk right out of the bottle. It also works with the existing POE, and mixing a little PAG in wont hurt it as well (using automotive charging equip that has PAG in it, as well as the use of dyed oil for leak finding). I didnt bother considering R-12, since its becoming so expensive. Something you may get a kick out of, is look up the blends in Freeze-12 (a "dropin" replacement that we used. I feel very ripped off). And speaking of which, AC-Hacker, you will like this link. The epa did something useful! Composition of Refrigerant Blends | Alternatives / SNAP | US EPA And to all you r-290 supporters, you may be entertained knowing I dissected a hotel minifridge to discover the compressor was rated for r-290, r-134a, and blends (USA Model)
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This list is rather dated. As you may or may not know, there are oodles of "new and natural" refrigerant blends on the market now. The OEM suppliers have now crossed the line of including "highly flammable" hydrocarbon refrigerants in the circuits of small appliances. The powers that be have been granted permission to do so below a certain mass of charge, and the mini-split and window-shaker market falls within the boundaries.
This trend has yet to penetrate the USA market, mainly confined to European and Asian markets. I believe it is just a matter of time until hydrocarbon refrigerants start appearing in refrigerators, dehumidifiers, and portable A/C units in the Americas. Your experience with the mini-fridge is living proof that at least a FEW of these units are being sold here now. But I can't help but believe that the r134 and r410 units are on borrowed time.