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November 1989
CONSUMERS' QUESTIONS AND ANSWERS
Refrigerants and the Atmosphere
This information is provided as a public service by the
Refrigeration Service Engineers Society and your heating
and air conditioning service contractor. It is intended
to provide clear, factual answers to questions about
stratospheric ozone depletion, what is being done about
it, and how the situation will affect you.
Q: WHAT IS OZONE?
Ozone is a gas. It consists of three atoms of oxygen in
each molecule; the oxygen we breathe contains two atoms
in each molecule. Chemically, oxygen is O2, and ozone
is O3. The *ozone layer* consists of ozone in the
stratosphere, high above the earth at an altitude of
between 7 and 28 miles. It is formed by ultraviolet
light from the sun acting on oxygen molecules. The
ozone layer absorbs and scatters ultraviolet light from
the sun, preventing harmful amounts of ultraviolet from
reaching the earth. For this reason, it is often
referred to as the Ozone Shield.
Q: BUT ISN'T OZONE UNHEALTHFUL?
Yes, when it occurs in the lower atmosphere where we
breathe it. This is caused by ultraviolet radiation
from the sun acting on smog and air pollutants on hot
Summer days. This situation should not be confused with
the protective ozone layer in the stratosphere. Ozone
at ground level is a harmful pollutant; in the
stratosphere it is a protective shield.
WHAT ARE CFCs?
- chlorofluorocarbon*; chemicals that CFC stands for
contain chlorine, fluorine and carbon, and may contain
hydrogen. These chemicals are inexpensive, safe,
non-flammable refrigerants of high thermal efficiency.
They are also used as solvents in cleaning electronic
microcircuits, and as the blowing agent in manufacturing
foam insulations. There are some other uses, as well.
In many other countries, CFCs are still used as aerosol
propellants.
CFC is the general term often used inaccurately for all
these compounds. It is important to realize that not
all *CFCs* are equally suspected of affecting the
atmosphere. CFCs which contain chlorine but no hydrogen
(fully halogenated CFCs) are the real problem. Those
which contain no chlorine, only fluorine (HFCs), and
those which contain hydrogen along with chlorine
(HCFCs), have a far smaller effect, if any at all.
Q: WHAT DO CFCs DO TO THE OZONE LAYER?
Certain chlorine-containing refrigerants are so stable
that they do not break down in the lower atmosphere,
even a hundred years or more after being released.
These chemicals gradually float up to the stratosphere,
where the chlorine reacts with ozone, causing it to
change back to oxygen. The chlorine is not used up in
the reaction; each molecule goes on to cause more and
more ozone-to-oxygen reactions.
Q: ARE THERE OTHER CHEMICALS THAT HAVE THE SAME EFFECT?
Yes; bromine-containing compounds, such as contained in
certain *halon* fire extinguishers, also have been
implicated in potential ozone depletion. Bromine is
chemically related to chlorine.
Q: WHAT IS THE RESULT?
Depletion of the ozone layer could result in increased
exposure to ultraviolet radiation at some point in the
future. The best available scientific information
indicates that proper action taken now to reduce
consumption of fully halogenated CFCs should avoid
possible future effects on humans and the environment.
Potential effects include increases in skin cancer and
cataracts, inability to resist certain infectious
diseases, decreased yields of agricultural crops, and
effects on marine life that is essential to the food
chain.
Q: WHAT IS THE *OZONE HOLE* I'VE READ ABOUT?
This is a thinning in the ozone layer over Antarctica,
which occurs during the Antarctic Spring season (Autumn
in the Northern Hemisphere). It occurs over the
Antarctic continent due to the unique climate caused by
powerful circumpolar winds and extremely low
temperatures there; the lowest on earth. This area is
being carefully monitored for the degree to which ozone
thins out, since it has been found to lead to ozone
depletion in other parts of the world, as well.
Significantly reduced ozone levels were detected in
1985, and high chlorine levels were found in 1986.
Instrumented aircraft flights through this layer
indicate that the ozone depletion problem may be more
serious than initially thought.
Q: DIDN'T WE STOP USING CFCs IN SPRAY CANS FOR THIS
REASON?
During the early 1970s, CFCs used as aerosol propellants
constituted over 50% of total CFC consumption in the
U.S. Following concerns initially raised by Professor
Sherwood Rowland and Dr. Mario Molina in 1974, the
E.P.A. and the Food and Drug Administration in 1978
banned the use of CFCs as aerosol propellants in all but
a few essential applications. This use of CFCs was
reduced in the U.S. by approximately 95%.
Unfortunately, very few other countries followed the
U.S. in this ban. Because of the many practical uses of
CFCs, their production and use has now surpassed
pre-1974 levels.
Q: IS THIS THE SAME AS THE *GREENHOUSE EFFECT*?
No, but CFCs may be involved in this problem, also. The
greenhouse effect occurs when carbon dioxide (mostly
form the burning of fossil fuels; oil, natural gas, and
coal) and other gases (methane, nitrogen, oxides, and
others) build up in the atmosphere. These gases let
incoming sunlight and its heat reach the earth, but
block the earth's heat from radiating into space. This
is the way a greenhouse works, and so the name of the
effect. As the gases build up, more heat is trapped,
and the planet's temperature rises. Some scientists now
feel that CFCs may also be contributing to this effect.
Q: WHAT IS BEING DONE TO STOP DEPLETION OF THE OZONE
LAYER?
Scientists from around the world recognize the
importance and severe results of this problem, and
realize that all countries must cooperate to stop
erosion of the ozone shield.
In the Fall on 1987, representative of more than 30
nations, meeting in Montreal, Canada, signed an
agreement now known as the Montreal Protocol. The U.S.
and Canada were included. On August 1, 1988, the U.S.
Environmental Protection Agency (E.P.A.) enacted the
provisions of this agreement into regulations for the
United States.
The Montreal Protocol and the E.P.A. specify that as of
July 1, 1989, production and consumption of certain CFCs
will be limited to the levels produced and consumed in
1986. This actually means a cutback, because use has
grown since that time. In July, 1993, these levels will
be reduced by 20%, and to 50% of 1986 levels in July of
1998. Specifically, the chemicals involved are the
fully halogenated CFCs 11, 12, 113, 114, and 115.
Halons 1211, 1301, and 2402 are also covered, but on a
different time schedule. Scientific, technological,
and economic concerns are to be reviewed at least every
four years, with the first review in 1990.
The most recent technical information indicates that
even deeper cuts in production and use may be necessary.
The head of the E.P.A. has stated that these chemicals
should be completely eliminated, and some responsible
industry trade groups agree.
But all is not lost when it comes to our needs for
refrigerants.
It's important to remember that only fully halogenated
refrigerants are being phased down. The refrigerant in
home refrigerators, freezers and automotive air
conditioning is mostly CFC 12, one of those being
regulated. But central home air conditioning typically
uses HCFC 22.
Over a period of time, new appliances can be redesigned
to use HCFCs in place of fully halogenated CFCs.
Manufacturers of electronic microcircuits uses CFCs to
clean parts. They are successfully switching to other
chemicals.
Manufacturers of foam insulation use CFCs to produce the
insulating bubbles in the insulation. There are other
methods and chemicals they can used, although these
produce insulation that is less efficient.
New replacement refrigerators are also being developed,
but these will require years of testing for any toxic
effects, to make sure they are safe.
Q: CAN'T WE JUST SWITCH TO SOME OF THE OTHER
REFRIGERANTS?
Yes, but this is going to take time. HFC and HCFC
refrigerants can replace the CFCs, but the refrigeration
and air conditioning equipment has to be redesigned and
manufactured. The existing refrigerant in your
refrigerator, as an example, cannot be simply removed
and replaced with one of the other refrigerants, because
the compressor, cooling coil, and other components in
the system were designed for the specific refrigerant
being used. Different refrigerants have different
characteristics, which affect the compressor and other
components in the system.
A lubricating oil also has to be developed that will be
compatible with the new HCFCs and HFCs.
Q: HOW WILL THIS SITUATION AFFECT US?
As mentioned, insulation can be manufactured using other
methods and chemicals, but the result is less efficient;
greater thicknesses of insulation will have to be used
to get the same insulating effect. That will mean
refrigerators and freezers that are either larger on the
outside or smaller on the inside. Refrigerated trucks
can not be make larger on the outside, of course, and so
cargo capacity will be reduced. Carrying less frozen
food per trip will mean somewhat higher transportation
costs, which may increase some of the prices we pay.
Necessary changes in the processing of frozen foods may
also result in increased costs.
Refrigerators, freezers, and other systems using CFC-12
that are redesigned for other refrigerants will probably
be slightly less efficient, using more electricity for
operation. They may also be somewhat heavier.
The price your air conditioning service contractor pays
for refrigerant will increase, as a result of shorter
supplies. To help control these costs and make supplies
go farther, your service technician will take steps to
conserve, recover, and re-use refrigerants. It is
increasingly important to find and repair leaks in
systems, rather than just adding more refrigerant
periodically.
Existing residential appliances and systems should not
become obsolete nor have to be replaced any sooner.
Owners and operators of large commercial air
conditioners and refrigeration systems will probably
notice a great many more changes than the homeowner
will.
The more thoroughly we can prevent the escape of CFCs to
the atmosphere, and the more wisely we can conserve and
recycle these materials, the better we can protect our
health and that of generations to come, protect the
environment, and control our overall costs in the long
run.
This information was copied 12 October 1989 by
Jerry J. Trantow
Research Scientist
Johnson Controls, Inc.
507 E. Michigan Street MS-36
Milwaukee, Wi 53201
out of a bulletin from:
Refrigeration Service Engineers Society
1666 Rand Road
Des Plaines, Illinois 60016-3552
PHONE (312) 297-6464
FAX (312) 297-5038
with permission from Dean Lewis. If you would like an
original copy send a self-addressed stamped business
size (#10) envelope to RSES requesting a copy of
"Consumers' Question and Answers, Refrigerants and the
Atmosphere". Quantities are also available, call RSES
for details. The original bulletin has several color
pictures of the ozone hole, chemical reactions, etc.
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