1 Air Conditioning Refrigerants

2 Desirable Refrigerant Properties Non-Toxic Non-Flammable Chemically stable Resistance to chemical breakdown Easy to handle Non-Toxic Non-Flammable Chemically stable Resistance to chemical breakdown Easy to handle

3 Desirable Refrigerant Properties High latent heat of Vaporization Compatible with System Material Easily detectable Very available In most cases, environmentally friendly High latent heat of Vaporization Compatible with System Material Easily detectable Very available In most cases, environmentally friendly

4 CFC’s Facts about CFC’s: Contains –Chlorine –Flourine –Carbon Prime offender in Ozone depletion Has high ODP Atmospheric life of 100 years Production ceased Dec 31, 1995 Facts about CFC’s: Contains –Chlorine –Flourine –Carbon Prime offender in Ozone depletion Has high ODP Atmospheric life of 100 years Production ceased Dec 31, 1995

5 HCFC’s Facts about HCFC’s: Contains Hydrogen, Chlorine, Fluorine, and Carbon Not as damaging to the ozone layer Has much lower ODP Will decompose sooner because of Hydrogen atom Production will cease sometime in the twenty first century Facts about HCFC’s: Contains Hydrogen, Chlorine, Fluorine, and Carbon Not as damaging to the ozone layer Has much lower ODP Will decompose sooner because of Hydrogen atom Production will cease sometime in the twenty first century

6 HFC’s Facts about HFC’s: Contain Hydrogen, Fluorine, and Carbon No Ozone depletion Not compatible with mineral oil Virtually all refrigerants will be in this family Facts about HFC’s: Contain Hydrogen, Fluorine, and Carbon No Ozone depletion Not compatible with mineral oil Virtually all refrigerants will be in this family

7 Blends Refrigerants that are made by blending existing refrigerants. These were created as replacements for CFC’s Make sure that compatible oil is used Refrigerants that are made by blending existing refrigerants. These were created as replacements for CFC’s Make sure that compatible oil is used

8 Zeotropic Blends Many different boiling points Large Temperature glide Two column PT chart is used Must be charged in liquid state only –Very little fractionation occurs –If a large leak occurs, refrigerant must be recovered, leak fixed and virgin refrigerant charged Many different boiling points Large Temperature glide Two column PT chart is used Must be charged in liquid state only –Very little fractionation occurs –If a large leak occurs, refrigerant must be recovered, leak fixed and virgin refrigerant charged

9 Azeotropic Blends Mixture of refrigerants when combined they act like a single refrigerant A chemical process Can be charged as a Vapor or Liquid –Very little fractionation occurs –If a large leak occurs and can be fixed, just add refrigerant Examples –R500 (73.8% R12 and 26.2% R125a) –R502 (48.8% R22 and 52.2% R115) Mixture of refrigerants when combined they act like a single refrigerant A chemical process Can be charged as a Vapor or Liquid –Very little fractionation occurs –If a large leak occurs and can be fixed, just add refrigerant Examples –R500 (73.8% R12 and 26.2% R125a) –R502 (48.8% R22 and 52.2% R115)

10 Near Azeotropic Blends Has small temperature glide Usually, if leak occurs, it can be topped off with refrigerant without being recovered. May use only one column PT Chart Ex. R-410a Has small temperature glide Usually, if leak occurs, it can be topped off with refrigerant without being recovered. May use only one column PT Chart Ex. R-410a

11 Blend Fractionation When one refrigerant acts as a single refrigerant rather than a blend When two or more of the mixtures leak at a faster rate than the other Leaks are a Problem It is recommended to change all refrigerant in a major leak When one refrigerant acts as a single refrigerant rather than a blend When two or more of the mixtures leak at a faster rate than the other Leaks are a Problem It is recommended to change all refrigerant in a major leak

12 Mixing Refrigerants Never mix refrigerants You will be charged money to have them incinerated Never mix refrigerants You will be charged money to have them incinerated

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