1

Refrigerants and

refrigerant oil

Refrigerants and

refrigerant oil

2

The clean air act of 1990The clean air act of 1990

• The Environmental Protection Agency [EPA] enforces regulations set in place by the clean air act governing the repair and service of automotive air conditioning systems.

• Fines and prison terms have been imposed on technicians who have violated EPA rules on vent refrigerants into the atmosphere.

• The EPA monetarily rewards whistle blowers for information leading to prosecution of violators.

• The Environmental Protection Agency [EPA] enforces regulations set in place by the clean air act governing the repair and service of automotive air conditioning systems.

• Fines and prison terms have been imposed on technicians who have violated EPA rules on vent refrigerants into the atmosphere.

• The EPA monetarily rewards whistle blowers for information leading to prosecution of violators.

3

Technician certification Technician certification

• EPA section 609 states: All persons repairing or servicing motor vehicle air-conditioning (MVAC) systems for consideration [being paid for it] must be properly trained and certified by a program authorized by EPA.

• Refrigerant handlers certification is done through ASE, MACS [Mobile Air Conditioning Society] and other institution

• Currently certification is required for the purchase of R-12 but not for R-134a

• EPA section 609 states: All persons repairing or servicing motor vehicle air-conditioning (MVAC) systems for consideration [being paid for it] must be properly trained and certified by a program authorized by EPA.

• Refrigerant handlers certification is done through ASE, MACS [Mobile Air Conditioning Society] and other institution

• Currently certification is required for the purchase of R-12 but not for R-134a

4

Refrigerant propertiesRefrigerant properties

• A good refrigerant needs to be:– Low boiling point – well below 0 deg. F at

atmospheric pressure– High boiling point at pressures above 200 psi– Non toxic– Non flammable – Compatibility with refrigerant oil– Must be compatible with the rubber hoses and

seals usedin the A/C system– Have little or no effect on the environment– Inexpensive

• A good refrigerant needs to be:– Low boiling point – well below 0 deg. F at

atmospheric pressure– High boiling point at pressures above 200 psi– Non toxic– Non flammable – Compatibility with refrigerant oil– Must be compatible with the rubber hoses and

seals usedin the A/C system– Have little or no effect on the environment– Inexpensive

5

Refrigerant propertiesRefrigerant properties

• Ammonia is often used as a commercial refrigerant but cannot be used in automobiles due to it’s high toxicity.– The ammonia we see in household cleaners is

extremely dilute – about 1% by volume.– Inhaling the fumes from concentrated ammonia

can be fatal.

• Propane is an excellent refrigerant, but imagine what would happen if you were in a front end collision in a car that used propane as a refrigerant.

• Ammonia is often used as a commercial refrigerant but cannot be used in automobiles due to it’s high toxicity.– The ammonia we see in household cleaners is

extremely dilute – about 1% by volume.– Inhaling the fumes from concentrated ammonia

can be fatal.

• Propane is an excellent refrigerant, but imagine what would happen if you were in a front end collision in a car that used propane as a refrigerant.

6

Chlorofluorocarbons - CFCsChlorofluorocarbons - CFCs

• Automotive air conditioning systems installed on cars built before 1990 used refrigerant compounds made from:– Chlorine– Fluorine– Carbon– Hydrogen

• Chemicals containing these elements are known as CFCs

• R-12 was used on most cars prior to 1993.

• R-12 is dichlorodifluoromethane [CCL2F2]– R-12 was marketed by DuPont under the trade name

‘Freon’

• Automotive air conditioning systems installed on cars built before 1990 used refrigerant compounds made from:– Chlorine– Fluorine– Carbon– Hydrogen

• Chemicals containing these elements are known as CFCs

• R-12 was used on most cars prior to 1993.

• R-12 is dichlorodifluoromethane [CCL2F2]– R-12 was marketed by DuPont under the trade name

‘Freon’

7CFCs and the environmentCFCs and the environment

• In the 1980s it was determined that CFCs that were released into the atmosphere were destroying the ozone layer.

• Ozone is a form of oxygen [O3] that is present in the upper stratosphere at 20 to 30 miles above the earth’s surface.

• The ozone layer absorbs UV [ultra violet] radiation.

• UV radiation in small doses causes sunburn and skin cancer.

• If the ozone layer was to be totally destroyed all land base life on earth would be at risk.

• In the 1980s it was determined that CFCs that were released into the atmosphere were destroying the ozone layer.

• Ozone is a form of oxygen [O3] that is present in the upper stratosphere at 20 to 30 miles above the earth’s surface.

• The ozone layer absorbs UV [ultra violet] radiation.

• UV radiation in small doses causes sunburn and skin cancer.

• If the ozone layer was to be totally destroyed all land base life on earth would be at risk.

8

CFCs and the environmentCFCs and the environment

• Research in the 1980s revealed that it was the chlorine in CFCs that was damaging the ozone layer.

• As a result of the Montreal protocol of 1990 CFCs were phased out and replaced by HFCs [Hydrogen-fluorine-carbon] .

• The EPA at this time implemented rules requiring reclamation and recycling of refrigerants and began requiring the technicians who service auto A/C systems to be licensed in refrigerant recovery and handling.

• Research in the 1980s revealed that it was the chlorine in CFCs that was damaging the ozone layer.

• As a result of the Montreal protocol of 1990 CFCs were phased out and replaced by HFCs [Hydrogen-fluorine-carbon] .

• The EPA at this time implemented rules requiring reclamation and recycling of refrigerants and began requiring the technicians who service auto A/C systems to be licensed in refrigerant recovery and handling.

9

R-12R-12

• R-12 was used on all automotive A/C systems on vehicles built prior to 1990.

• The world wide production of R-12 has been banned but bootleg R-12 from Asia is still widely available.

• Recycled R-12 is also widely available • Only licensed A/C technicians can purchase

R-12• R-12 is the best option for keeping the A/C

system in an older car running.• R-12 boils at -21 deg F. • At 30 psi R-12 boils at 32 deg F.

• R-12 was used on all automotive A/C systems on vehicles built prior to 1990.

• The world wide production of R-12 has been banned but bootleg R-12 from Asia is still widely available.

• Recycled R-12 is also widely available • Only licensed A/C technicians can purchase

R-12• R-12 is the best option for keeping the A/C

system in an older car running.• R-12 boils at -21 deg F. • At 30 psi R-12 boils at 32 deg F.

10

R-134aR-134a

• R-134a replace R-12 in the early 1990s.• It contains no chlorine so it will not harm the

ozone layer but it is also a greenhouse gas.• The SAE is currently evaluating possible

replacements for RE-134a but the auto industry has not yet made a decision on what it will be.

• R-134a boils at -26 deg F when exposed to atmospheric pressure.

• At 27 psi R-134a will boil at 32 deg F.

• R-134a replace R-12 in the early 1990s.• It contains no chlorine so it will not harm the

ozone layer but it is also a greenhouse gas.• The SAE is currently evaluating possible

replacements for RE-134a but the auto industry has not yet made a decision on what it will be.

• R-134a boils at -26 deg F when exposed to atmospheric pressure.

• At 27 psi R-134a will boil at 32 deg F.

11

RetrofitsRetrofits

• In the late 1990s the cost of R-12 skyrocketed to over $30 a pound.

• Most vehicles built for R-12 were retrofitted to use R-134a or alternatives when their A/C systems needed service.

• Retrofitting to R-134a involved changing the service fittings and adding POE refrigerant oil that was compatible with the new refrigerant.

• A retrofit label that lists the type of refrigerant should have been installed at the time of retrofit.

• In the late 1990s the cost of R-12 skyrocketed to over $30 a pound.

• Most vehicles built for R-12 were retrofitted to use R-134a or alternatives when their A/C systems needed service.

• Retrofitting to R-134a involved changing the service fittings and adding POE refrigerant oil that was compatible with the new refrigerant.

• A retrofit label that lists the type of refrigerant should have been installed at the time of retrofit.

12

Blended refrigerantBlended refrigerant

• Some refrigerants are a mix of two or more chemicals.

• Since two chemicals have two different boiling points as refrigerant is lost slowly over time the chemical with the higher boiling point is lost at a faster rate.

• Blends were commonly used in retrofits in the 1900s and early 2000s.

• R-22 is a blend that was used in stationary A/C systems and sometimes found in some retrofit systems. It is not compatible with the rubber used in most automotive A/C systems and should never be used as an automotive refrigerant.

• Some refrigerants are a mix of two or more chemicals.

• Since two chemicals have two different boiling points as refrigerant is lost slowly over time the chemical with the higher boiling point is lost at a faster rate.

• Blends were commonly used in retrofits in the 1900s and early 2000s.

• R-22 is a blend that was used in stationary A/C systems and sometimes found in some retrofit systems. It is not compatible with the rubber used in most automotive A/C systems and should never be used as an automotive refrigerant.

13

Future refrigerantsFuture refrigerants

• Two refrigerants that are often mentioned as possible replacements for R-134a are:– R-152a

– CO2 [Carbon Dioxide]

• R-152a has all the properties of an excellent refrigerant except that it is toxic– The system would have to locate the evaporator

outside the cabin to utilize R-152a

• CO2 is an excellent refrigerant but needs to be compressed to very high pressures [over 700 psi]

• Two refrigerants that are often mentioned as possible replacements for R-134a are:– R-152a

– CO2 [Carbon Dioxide]

• R-152a has all the properties of an excellent refrigerant except that it is toxic– The system would have to locate the evaporator

outside the cabin to utilize R-152a

• CO2 is an excellent refrigerant but needs to be compressed to very high pressures [over 700 psi]

14

Refrigerant containersRefrigerant containers

• Refrigerant is sold in 30 lbs. disposable tanks and 12 oz. cans.

• Refrigerant tanks are color coded.– R-12 is white– R-134a is light blue

• Refrigerant tanks for R-12 have a 7/16” x 20 conventional threaded fitting for hose attachment.

• Refrigerant tanks for R-134a have a ½” x 16 Acme thread fitting for the hose connection.

• Refrigerant is sold in 30 lbs. disposable tanks and 12 oz. cans.

• Refrigerant tanks are color coded.– R-12 is white– R-134a is light blue

• Refrigerant tanks for R-12 have a 7/16” x 20 conventional threaded fitting for hose attachment.

• Refrigerant tanks for R-134a have a ½” x 16 Acme thread fitting for the hose connection.

15

Refrigerant oilRefrigerant oil

• The bearings and rings in the compressor and the expansion valve require a continuous supply of lubrication oil.

• A few ounces of oil circulate with the refrigerant and keep all of the mechanical components well lubricated.

• The oil must have a low viscosity to prevent it from turning into wax and blocking the orifice/expansion valve where temperatures will be around 32 deg. F.

• The bearings and rings in the compressor and the expansion valve require a continuous supply of lubrication oil.

• A few ounces of oil circulate with the refrigerant and keep all of the mechanical components well lubricated.

• The oil must have a low viscosity to prevent it from turning into wax and blocking the orifice/expansion valve where temperatures will be around 32 deg. F.

16

Mineral oilMineral oil

• R-12 systems used a mineral oil type lubricant.

• Mineral cannot be used in R-134a systems– It will congeal at the bottom of the condenser

and evaporator blocking the flow of refrigerant.

• Normally light yellow color• Available in 500 or 525 viscosity• Slightly hygroscopic – like brake fluid it

absorbs water

• R-12 systems used a mineral oil type lubricant.

• Mineral cannot be used in R-134a systems– It will congeal at the bottom of the condenser

and evaporator blocking the flow of refrigerant.

• Normally light yellow color• Available in 500 or 525 viscosity• Slightly hygroscopic – like brake fluid it

absorbs water

17

PAGPAG

• Polyalkylene glycol• Synthetic oil chemically similar to antifreeze• Developed for R-134a systems• Light blue color• Available in 3 viscosities 46, 100 and 150– Most late model cars that use Asian compress

require PAG 46– Older domestic compressors normally require

PAG 150

• Highly hygroscopic – avoid skin contact

• Polyalkylene glycol• Synthetic oil chemically similar to antifreeze• Developed for R-134a systems• Light blue color• Available in 3 viscosities 46, 100 and 150– Most late model cars that use Asian compress

require PAG 46– Older domestic compressors normally require

PAG 150

• Highly hygroscopic – avoid skin contact

18

Ester - POEEster - POE

• Polyol Ester [POE] is compatible with both R-12 and R-134a so it was used in most retrofits

• Clear color – no tint• Slightly hygroscopic• Although it is marketed as a universal oil it

should not be used in R-134a systems as PAG is a much better lubricant

• Polyol Ester [POE] is compatible with both R-12 and R-134a so it was used in most retrofits

• Clear color – no tint• Slightly hygroscopic• Although it is marketed as a universal oil it

should not be used in R-134a systems as PAG is a much better lubricant

19

A/C system placardA/C system placard

• By law new vehicle must have an A/C system placard under the hood that lists:– The type of refrigerant used – The volume of refrigerant needed to fully charge

the system– Normally the type and amount of refrigerant oil

is also displayed

• The placard color for R-134a systems should be gold and yellow

• By law new vehicle must have an A/C system placard under the hood that lists:– The type of refrigerant used – The volume of refrigerant needed to fully charge

the system– Normally the type and amount of refrigerant oil

is also displayed

• The placard color for R-134a systems should be gold and yellow

20

Refrigerant identificationRefrigerant identification

• When servicing new cars the type of refrigerant is stated on the A/C system placard under the hood.

• When working on and older car the refrigerant listed on the placard may not be what was originally used when the car was built.

• When servicing new cars the type of refrigerant is stated on the A/C system placard under the hood.

• When working on and older car the refrigerant listed on the placard may not be what was originally used when the car was built.

• Refrigerant identifier machines are available that can chemically analyze the refrigerant currently in the system so that proper recovery can be done.

• Refrigerant identifier machines are available that can chemically analyze the refrigerant currently in the system so that proper recovery can be done.

21

DesiccantsDesiccants

• Desiccants are chemicals that absorb moisture.

• A porous bag of desiccant material is installed inside the accumulator or receiver drier to absorb any moisture that may find it’s way into the system.

• Water in the system can freeze and block the orifice so that no cooling occurs.

• Water also reacts with refrigerant to form acid that corrodes metal parts.

• The receiver/drier or accumulator are normally replaced anytime a component is replaced in the system.

• Desiccants are chemicals that absorb moisture.

• A porous bag of desiccant material is installed inside the accumulator or receiver drier to absorb any moisture that may find it’s way into the system.

• Water in the system can freeze and block the orifice so that no cooling occurs.

• Water also reacts with refrigerant to form acid that corrodes metal parts.

• The receiver/drier or accumulator are normally replaced anytime a component is replaced in the system.

22

UV leak detector dyesUV leak detector dyes

• The source of small A/C system leaks are normally detected by adding a dye to the refrigerant and inspecting the system using a UV light source.

• The dye glows yellow/green when illuminated by UV light.

• Dye can be introduce into the system with a small can of refrigerant mixed with dye, adding liquid dye concentrate to the refrigerant during a recharge or with a special syringe.

• The source of small A/C system leaks are normally detected by adding a dye to the refrigerant and inspecting the system using a UV light source.

• The dye glows yellow/green when illuminated by UV light.

• Dye can be introduce into the system with a small can of refrigerant mixed with dye, adding liquid dye concentrate to the refrigerant during a recharge or with a special syringe.