Selected Refrigerant Data
|R11||75F||CCl3F||Orange||A=Not Toxic||1=Not Flammable||-|
|R12||-21.6F||CCl2F2||White||A=Not Toxic||1=Not Flammable||TXV has yellow top|
|R22||-41F||CHClF2||Lt. Green||A=Not Toxic||1=Not Flammable||-|
|R134A||-15F||C2H2F4||Lt. Sky Blue||A=Not Toxic||1=Not Flammable||-|
|R410A||-61F||Blend||Rose||A=Not Toxic||1=Not Flammable||AZ-20|
|R718||212F||H2O||Clear||A=Not Toxic||1=Not Flammable||Water|
Classes of Refrigerants
- A=Not Toxic
- 1=Not Flammable
The 3 R's of HVAC
- Recover - Remove refrigerant without filtering and store in an approved EPA container
- Recycle - Remove refrigerant, filter for nositure, oil and debris, then store in an approved EPA container
- Reclaim - Remove refrigerant, send to processing facility, where it is chemically tested and reprocessed in accordance with ARI-700
- Phosgene originated as a nerve toxin in World War I
- It is produced from the combustion of chlorine-flourine compounds,or when they come contact with hot metal or flame
- Brazing causes combustion - Special care MUST be taken
- Density: Heavier than air
- Has a blue-green color when combustion takes place
- Is considered to be a carcinogen, even at low exposure levels
- Physical retention is accumulative - It does NOT dissipate over time
- Alkyl Benzene Oil - A synthetic refrigeration oil commonly known as Zerol.
- Alternative Refrigerant - any of a number of refrigerants or refrigerant mixtures designed to replace the current CFC or HCFC refrigerants.
- Azeotrope - A mixture made up of two or more refrigerants with similar boiling points that act as a single fluid. The components of azeotropic mixtures will not separate under normal operating conditions and can be charged as a vapor or liquid.
- CFC Refrigerant - CFC refers to the chemical composition of the refrigerant. ChloroFluoroCarbon indicates that the refrigerant is comprised of Chlorine, Fluorine, and Carbon. Common CFC refrigerants are R11, 12,13,113,114, and 115.
- Drop-In Replacement - An alternative refrigerant that can be installed directly into an existing system with minor equipment changes. Most interim alternatives fall into this category.
- Ester Oil - A general term that applies to a family of synthetic refrigeration oils based on the chemistry of polyol esters. Ester oils are generally regarded as the oil to use with most of the alternative refrigerants. Ester oils are generally compatible with existing mineral oils, and system components. Ester oils are slightly hygroscopic and should be in non-porous containers.
- Forane - Atochem trade name for alternative refrigerants.
- Global Warming Potential - Global warming occurs when solar energy penetrates the atmosphere and the resultant infrared energy from the earth's surface is absorbed by certain gases and not allowed to leave. This process is commonly known as the greenhouse effect. Refrigerants are normally rated on a scale from 1 to 10.
- HCFC Refrigerant - HCFC refers to the chemical composition of the refrigerant. HydroChloro-Fluoro-Carbon indicates that the refrigerant is comprised of Hydrogen, Chlorine, Fluorine, and Carbon. Common HCFC refrigerants are R22.
- HFC Refrigerant - HFC refers to the chemical composition of the refrigerant. HydroFluoroCarbon indicates that the refrigerant is comprised of Hydrogen, Fluorine, and Carbon. Common HFC refrigerants are R134a.
- High Pressure Refrigerants (HP) - A term used for some alternative refrigerants designed to operate in the low temperature (-35° F to 0° F) range.
- Hygroscopic - A tendency for refrigeration oils to absorb moisture from the atmosphere.
- Interim Replacements (SHORT TERM) - Any of a number of refrigerants intended to serve as an intermediate solution during the transition from CFC to HFC refrigerants. Most interim replacements contain HCFC refrigerants like R22.
- Klea - I.C.I. Company trade name for alternative refrigerants.
- Long Term Replacements - Alternative refrigerants that are considered to have no adverse affect on the stratospheric ozone layer. Most long term replacements are HFC compounds.
- Medium Pressure Refrigerant (MP) - A term used for some alternative refrigerants designed to operate in the medium temperature (0° F to 4° F) range.
- Mineral Oil - Refrigeration oil currently in use but is not compatible with most of the alternative refrigerants. Refrigerant conversions often require. a procedure for the removal of existing mineral oil because of the incompatibility with alternative refrigerants.
- Near Azeotrope - A mixture made up of two or more refrigerants with different boiling points that, when in a totally liquid or vapor state, act as one component. However, when changing from vapor to liquid or liquid to vapor, the individual refrigerants -evaporate or condense at different temperatures. Near-azeotropic mixtures have a temperature glide (see below) of less than 10° F and should be charged in the liquid state to assure proper mixture (non-azeotropic) composition.
- Ozone Depletion Potential (ODP) - This is a relative indication of the effect of the chlorine in CFC's on breaking down the ozone layer. It is measured on a scale from 0 to 1 with 0 being non-depleting and 1 being the highest depleting.
- P.A.G. Oil - A general term that applies to a family of synthetic oils based on the chemistry of Polyalkyline Glycols. The primary application of P.A.G. oils will be for automotive air conditioning.
- Refrigerant - is a substance used in a heat cycle usually including, for enhanced efficiency, a reversible phase change from a gas to a liquid. Traditionally, fluorocarbons, especially chlorofluorocarbons were used as refrigerants, but they are being phased out because of their ozone depletion effects. Other common refrigerants used in various applications are ammonia, sulfur dioxide, and non-halogenated hydrocarbons such as methane.
- Suva - DuPont Company trade name for alternative refrigerants, replaces the Freon trade name.
- Temperature Glide - the temperature difference that occurs between the vapor state and liquid state during evaporation or condensation at constant pressure, i.e. the temperature in the evaporator and condenser is not constant. Temperature glide occurs in near-azeotropic and zeotropic mixtures.
- Zeotrope - A mixture made up of two or more refrigerants with different boiling points. Zeotropic mixtures are similar to near-azeotropic mixtures with the exception of having a temperature glide greater than 10° F. Zeotropic mixtures should be charged in the liquid state.
Link For Refrigerant DataSheets
|The ideal refrigerant:
Until concerns about depletion of the ozone layer arose in the 1980s, the most widely used refrigerants were the halomethanes R-12 and R-22, with R-12 being more common in automotive air conditioning and small refrigerators, and R-22 being used for residential and light commercial air conditioning, refrigerators, and freezers. Some very early systems used R-11 because its relatively high boiling point allows low-pressure systems to be constructed, reducing the mechanical strength required for components. New production of R-12 ceased in the United States in 1995, and R-22 is to be phased out by 2020. R-134a and certain blends are now replacing chlorinated compounds. One popular 50/50 blend of R-32 and R-125 now being increasingly substituted for R-22 is R-410A, often marketed under the trade name Puron. Another popular blend of R-32, R-125, and R-134a with a higher critical temperature, and lower GWP than R-410A is R-407C. While the R-22 and other ozone depleting refrigerants are being phased out, they still have value and can be sold but not manufactured.
Following the ban on chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), substances used as substitute refrigerants such as fluorocarbons (FCs) and hydrofluorocarbons (HFCs) have also come under criticism. They are currently subject to prohibition discussions on account of their harmful effect on the climate. In 1997, FCs and HFCs were included in the Kyoto Protocol to the Framework Convention on Climate Change. In 2006, the EU adopted a Regulation on fluorinated greenhouse gases, which makes stipulations regarding the use of FCs and HFCs with the intention of reducing their emissions. The provisions do not affect climate-neutral natural refrigerants.
Early mechanical refrigeration systems employed sulfur dioxide gas or anhydrous ammonia, with small home refrigerators primarily using sulfur dioxide gas. Being toxic, sulfur dioxide rapidly disappeared from the market with the introduction of CFCs. Ammonia (R717) has been used in industrial refrigeration plants for more than 130 years and is deemed to be environment-friendly, economical, and energy-efficient. The natural refrigerant carbon dioxide (R744) has a similarly long tradition in refrigeration technology.
Occasionally, one may encounter older machines which used other transitional refrigerants such as methyl formate, chloromethane, or dichloromethane (called carrene in the trade). Perhaps the most common of these to still retain a charge are the methyl formate Monitor Top refrigerators produced by General Electric.
Use of highly purified propane as a refrigerant is gaining favor, especially in systems designed for R-22. Moreover, propane is non-toxic. An odorant, such as ethyl mercaptan, can be added in trace amounts to alert persons of system leaks.
Emissions from automotive air-conditioning are a growing
concern because of their impact on climate change. From 2011 on, the
European Union will phase out refrigerants with a global warming
potential (GWP) of more than 150 in automotive air conditioning (GWP =
100 year warming potential of one kilogram of a gas relative to one
kilogram of CO2). This will ban potent greenhouse gases such
as the refrigerant HFC-134a—which has a GWP of 1410—to promote safe and
energy-efficient refrigerants. One of the most promising alternatives
is the natural refrigerant CO2 (R-744). Carbon dioxide is
non-flammable, non-ozone depleting, has a global warming potential of
1, but is toxic and potentially lethal in concentrations above 5% by
volume. R-744 can be used as a working fluid in climate control systems
for cars, residential air conditioning, hot water pumps, commercial
refrigeration, and vending machines. R12 is compatible with mineral
while R134a is compatible with synthetic oil. GM has announced that it
will start using HFO-1234yf in all of its brands by 2013. Hydrofluoro
olefin (HFO)-1234yf, which is considered to have the highest potential
for replacing R-134a. This new refrigerant has a GWP rating of 4 and is
not a blend.
Dimethyl ether (DME) is also gaining popularity as a refrigerant.
Some refrigerants, such as tetrafluoroethane, are seeing
rising use as recreational drugs,
leading to an extremely dangerous phenomenon known as inhalant abuse.
Refrigerants by class
Refrigerants may be divided into three classes according to their manner of absorption or extraction of heat from the substances to be refrigerated:
Main article: List of refrigerants
The R-# numbering system was developed by DuPont and systematically identifies the molecular structure of refrigerants made with a single halogenated hydrocarbon. The meaning of the codes is as follows:
For example, R-134a has 4 fluorine atoms, 2
hydrogen atoms, 2 carbon atoms, with an empirical formula of
tetrafluoroethane. The "a" suffix indicates that the isomer is
unbalanced by one atom, giving 1,1,1,2-Tetrafluoroethane. R-134
(without the "a" suffix) would have a molecular structure of
1,1,2,2-Tetrafluoroethane—a compound not especially effective as a
The same numbers are used with an R- prefix for generic
refrigerants, with a "Propellant" prefix (e.g., "Propellant 12") for
the same chemical used as a propellant for an aerosol spray,
and with trade names for the compounds, such as "Freon 12". Recently, a
practice of using HFC- hydrofluorocarbons,
CFC- for chlorofluorocarbons,
and HCFC- for hydrochlorofluorocarbons
has arisen, because of the regulatory differences among these groups.
Air as a Refrigerant
Yet, with suitable compression and expansion technology, air can be a practical (albeit not the most efficient) refrigerant, free of the possibility of environmental contamination or damage, and almost completely harmless to plants and animals.
DuPont Replacement & Retrofit Guide