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anyone know anything about the refrigerant 421a? Supposed to be a direct replacement for 22. opinions? I was told it was a blend of 125 and 134.:huh:
 

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You have to change the metering device. It takes a larger orifice. And on TXV systems, will usually take a larger TXV.

So if you were converting a heat pump, its would be a lot of work.
 

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I can't see that , seeing as though the pressure temp. relationship is almost identical at low temps and within 2 or 3 psi even at high temps....that is verrrrry close. My only concern is the oil compatibility.
 
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