Z2TT

26-12-2015, 09:52 AM

Hi Guys.

I'm comparing R12 and R134a, most tradies or refrigeration mechanics who work on Automotive say that R134a is less efficient, is a worse conductor of heat and that R12 was a great refrigerant.

However I am trying to find out what technical data supports that. Most technical documents from compressor manufacturers mention that R134a is actually a more efficient refrigerant as it has a greater refrigerating affect so I'm trying to understand how it is a worse refrigerant than R12.

I have been comparing values of latent heat of vaporization - R12 is about 166 kj/kg and r134a is 215kg/kg, which means for R134a that for any given liquid amount in the evaporator, it can absorb more energyfrom the incoming air from the blower until it evaporates compared to R12, which would mean it can cool more air for a longer time.

I am wondering what exactly is it that makes R134a less efficient than R12, is it something to do with the required amount of energy required at the condensing stage to condense it into liquid, as it appears in the evaporation stage it is able to do much more work. All I know is that it runs at slightly higher pressures at the high side but it appears the trade off is worth it.

Thanks.

I'm comparing R12 and R134a, most tradies or refrigeration mechanics who work on Automotive say that R134a is less efficient, is a worse conductor of heat and that R12 was a great refrigerant.

However I am trying to find out what technical data supports that. Most technical documents from compressor manufacturers mention that R134a is actually a more efficient refrigerant as it has a greater refrigerating affect so I'm trying to understand how it is a worse refrigerant than R12.

I have been comparing values of latent heat of vaporization - R12 is about 166 kj/kg and r134a is 215kg/kg, which means for R134a that for any given liquid amount in the evaporator, it can absorb more energyfrom the incoming air from the blower until it evaporates compared to R12, which would mean it can cool more air for a longer time.

I am wondering what exactly is it that makes R134a less efficient than R12, is it something to do with the required amount of energy required at the condensing stage to condense it into liquid, as it appears in the evaporation stage it is able to do much more work. All I know is that it runs at slightly higher pressures at the high side but it appears the trade off is worth it.

Thanks.