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Modern Refrigeration and Air Conditioning
6.1 Refrigerants and the
Ozone Layer
In the 1970s, satellites were placed in orbit to exam-
ine the climate of the earth. One thing scientists stud-
ied with these satellites was the protective gaseous
layer—composed primarily of ozone (O3)—located in
the earth’s atmosphere. One surprising discovery was
that the protective layer of ozone had a hole in it.
The ozone layer acts as a filter for the sun’s ultra-
violet rays. This protects human, plant, and animal life
from the damaging effects of these rays, Figure 6-1.
The ozone layer also assists in maintaining stable tem-
peratures. Scientists believe that depletion of the ozone
layer can have harmful effects, such as climate change
and an increase in skin cancer and eye damage.
Scientists have determined that ozone layer deple-
tion is a result of numerous man-made gases that
escape and rise up into the atmosphere. One group of
these gases is chlorofluorocarbons (CFCs). Destruction
of the ozone layer by the release of CFCs into the atmo-
sphere is of great concern. In addition, hydrochloroflu-
orocarbons (HCFCs) and hydrofluorocarbons (HFCs),
which are also used as refrigerants, have been shown
to contribute to climate change as well.
In an attempt to stop ozone depletion, a treaty
was signed that banned the production of CFCs in all
large, developed countries. The treaty, which went into
effect on January 1, 1989, was known as the Montreal
Protocol. The Montreal Protocol required the United
States and other developed countries to stop produc-
ing CFC refrigerants by January 1, 1996. The banning
of CFCs resulted in the largest development program
to invent new refrigerants since the early days of
refrigeration.
6.1.1 The Clean Air Act
and EPA Regulations
The Environmental Protection Agency (EPA)
is a US governmental agency charged with enforc-
ing the regulations for working with refrigerants. The
Clean Air Act is a federal law that includes guidelines,
restrictions, and penalties for releasing refrigerants
into the atmosphere. Fines are assessed, up to $37,500
per day, for failure to comply with the Clean Air Act.
The following is a partial list of violations subject to
legal action:
• Venting of CFC, HCFC, and HFC refrigerants into
the atmosphere.
• Failure to recover refrigerant to required evacuation
levels before opening equipment for maintenance.
• Falsifying records or failure to keep records.
• Performing refrigeration work without having
technician certification according to the Clean Air
Act Section 608.
• Disposing of refrigeration and air conditioning
equipment or cylinders without fully recovering
or reclaiming the refrigerant.
• Using recovery equipment that is not EPA
approved.
The implementation of these laws has resulted in a
significant change in refrigerant handling by HVACR
technicians. It is necessary to be certified and trained
in how to perform refrigerant recovery, recycling, and
reclamation. These regulations are intended to prevent
significant purposeful releases of refrigerants into the
atmosphere. However, there are exceptions that allow
service technicians to reasonably do their job.
UV radiation
Ozone depletion
leads to thinner
ozone layer
and holes
Increased UV radiation
reaches earth
Ozone layer
(O3)
CFCs
released
into
atmosphere
Earth Earth
Normal Ozone Layer Depleted Ozone Layer
CFCs react
with O3 to
create O2
(oxygen)
Goodheart-Willcox Publisher
Figure 6-1. The depletion of the ozone layer allows increased ultraviolet radiation to reach the earth. This increased radiation has
negative effects on human health and the earth’s climate.