Common Refrigerants and Environmental Safety

What is a refrigerant?

A refrigerant is a chemical that is used to provide cooling in a heat transfer system.

Types of refrigerants

Chlorofluorocarbons (CFCs)

These are refrigerants that contain Chlorine, Fluorine and Carbon. They were developed in the 1930's and were used in a variety of industrial, commercial, household and automotive applications. They were ideal for commercial, household, and automotive use due to the fact that they are non-toxic, non-flammable, and non-reactive with other chemical compounds. In 1973 however, it was discovered that the Chlorine atom in the CFC's unfortunately is a catalyst for ozone depletion. Basically the Cl atom rips away the extra oxygen atom in the ozone compound. Since 1987 their use has been prohibited by the Montreal_Protocol.

The following animation demonstrates how CFC molecules destroy ozone molecules

o3split.gif
  • A chlorine atom is broken off of a CFC molecule by UV radiation.
  • The chlorine atom breaks apart the ozone molecule (O3), resulting in an oxygen molecule (O2) and a chlorine monoxide molecule (ClO).
  • A free oxygen atom breaks apart the chlorine monoxide molecule (ClO), releasing the chlorine atom and forming an oxygen molecule(O2).
  • The chlorine atom can now break apart another ozone molecule (O3). One chlorine atom can continue to break up ozone thousands of times.

CFC list with descriptions

R11
R12
R13
R13B1
R113
R114
R500
R502
R503

Hydrochlorofluorocarbons (HCFCs)

These are refrigerants that contain Hydrogen, Chlorine, Fluorine, and Carbon. They have only about 10% of the ozone depleting potential as CFCs. They are energy-efficient, low-in-toxicity, cost effective and can be used safely. They have allowed the CFCs consumption of the world to fall by about 75%. Unfortunately HCFCs are Greenhouse_gases, despite their very low atmospheric concentrations.

HCFC list with descriptions

R22
R123
R124
R401A
R401B
R402A
R403B
R408A
R409A
R414B
R416A

Hydrofluorocarbons (HFC's).

These are refrigerants containing Hydrogen, Fluorine, and Carbon. Therefore they do not contain any ozone depleting Chlorine. Besides containing no ozone depleting elements they usually have an even lower global warming potential than HCFCs. Unfortunately they are targets of the Kyoto_Protocol because they have activity in an entirely different realm of greenhouse gases.

HFC list with descriptions

R23
R134a
R404A
R407C
R410A
R417A
R422A
R422B
R422D
R507
R508B

Refrigerants with the least environmental impact.

The following chart shows the ozone depletion potential(ODP) and global warming potential(GWP) values for common CFC's, HCFC's, and HFC's.

44475Calmfig02j_00000020215.jpg

Because of their ozone depletion characteristics, CFC's have been phased out and HCFC's are in the process of being phased out. The United States is now resorting to the development and use of HFC's to take the place these refrigerants. Two of the most environmentally safe HFC's are HFC-32 and HFC-152a. These two refrigerants have zero ODP values and extremely low GWP values. The following two tables give the specs of each of these HFC's.

Difluoromethane HFC-32

Difluromethane

Difluoroethane HFC - 152a

Difluoroethane

Other new age alternatives

Most of these are "drop in" alternatives for CFC R12, HFC R134a, HCFCs R22, R502 and R11. Most are also natural organic refrigerants.

The list with descriptions

HR12
HR22/502
HR290
HR600a

HC-12a
HC-22a
HC-502a

References

05 Dec. 2007 <http://www.hpac.com/Content/Site019/Articles/01_01_2007/44475Calmfig02j_00000020215.jpg>.

"CFCs, HCFCs, HFCs." National Refrigerants. 05 Dec. 2007 <http://www.refrigerants.com/>.

"Chlorofluorocarbons and Ozone Depletion." CIESIN Thematic Guides. 05 Dec. 2007 <http://www.ciesin.columbia.edu/TG/OZ/cfcozn.html>.

"Haloalkane." Wikipedia. 05 Dec. 2007 <http://en.wikipedia.org/wiki/Haloalkane>.

"HR12, HR22/502, HR209, HR 600a." Making HCs Work for You. 05 Dec. 2007 <http://www.hychill.com.au/products/>.

"Refrigerant Resource Center." McQuay International. 05 Dec. 2007 <http://www.mcquay.com/McQuay/DesignSolutions/RefrigerantResourceCenter>.

"Stratospheric Ozone, the Protector." The University Corporation for Atmospheric Research. 05 Dec. 2007 <http://www.ucar.edu/learn/1_6_1.htm>.

"HCFCs the Proven Solution." The Alliance for Responsible Atmospheric Policy. 05 Dec. 2007 <http://www.arap.org/docs/hcfc.html>.

"THE FACTS ON HYDROCARBON REFRIGERANTS." Mac Freeze Refrigerants. 05 Dec. 2007 <http://www.macfreeze.com/referfacts.htm>.

"The World’S First and Only Patented, Environmentally Friendly HC Refrigerant." Fox Tool Supply. 05 Dec. 2007 <http:www.foxtoolsupply.com>.

"Toward a Safer Refrigerant." Global Spec. 05 Dec. 2007 <http://www.cheresources.com/saferefrig.shtml>.

Created by:

Timothy Bagatti (Princess)
Mike Durka (Durka Durka Durka Durka Durka….)
Brandon Young (Bring um Young)

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