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Air ConditioningAir Conditioning

RefrigerantsRefrigerants

2Desirable Refrigerant PropertiesDesirable 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

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Desirable Refrigerant PropertiesDesirable 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

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CFC’sCFC’sFacts 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

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HCFC’sHCFC’sFacts 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

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HFC’sHFC’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

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BlendsBlends

• 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

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Zeotropic BlendsZeotropic 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

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Azeotropic BlendsAzeotropic 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)

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Near Azeotropic BlendsNear 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

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Blend FractionationBlend 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

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Mixing RefrigerantsMixing 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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