Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

Glossary
Glossary
Absolute pressure
The actual pressure, where a true vacuum is the zero value, and so
atmospheric pressure is approximately 1.013 bar.
Accumulator
A vessel capable of holding liquid refrigerant and permanently connected
between the exit of the evaporator and suction of the compressor.
Air-conditioning
It is the process of controlling temperature, humidity, composition, and
distribution of air for the purpose of human comfort or for special technical
need of a industrial process (pharmaceutical, textile, etc.) or other application.
Article 2 countries
Parties to the Montreal Protocol that do not operate under Article 5. “Article 2
countries” refer to developed countries.
Article 5 countries
Developing country Parties to the Montreal Protocol whose annual per capita
consumption and production of ozone depleting substances (ODS) is less
than 0.3 kg to comply with the control measures of the Protocol, are referred
to as Article 5 countries. Currently, 147 of the 196 Parties to the Montreal
Protocol meet these criteria. Article 5 countries are eligible to receive technical
and financial assistance from the Multilateral Fund Secretariat, as per Article
10 of the Protocol.
Atmospheric lifetime
A measure of the average time that a molecule remains intact once released
into the atmosphere.
Atmospheric pressure
Also known as barometric pressure. It is the pressure exerted by the
atmosphere above the surface of the Earth. Standard sea level pressure is a
unit of pressure and, by definition, equals 1 atmosphere (atm) or 101.35 kPa.
Azeotrope
A blend consisting of one or more refrigerants of different volatilities that does
not appreciably change in composition or temperature as it evaporates (boils)
or condenses (liquefies) under constant pressure. Refrigerant blends assigned
an R5xx series number designation by ISO 817 are azeotropes.
Banks
The total amount of substances contained in existing equipment, chemical
stockpiles, foams and other products not yet released to the atmosphere.
Blends (mixtures)
A mixture of two or more pure fluids. Blends are used to achieve properties
that fit many refrigeration purposes. For example, a mixture of a high pressure
and a low pressure substance mixed in order to match the pressure of
another substance. Blends can be divided into two categories: azeotropic,
and zeotropic blends.
Boiling point
The temperature of a liquid at the point it starts to vaporize (see NBP).
Brazed joint
A joint obtained by the joining of metal parts with alloys which melt at
temperatures in general higher than 450°C but less than the melting
temperatures of the joined parts
Bubble point
Liquid saturation temperature of a refrigerant at the specified pressure; the
temperature at which a liquid refrigerant first begins to boil.
Cascade system
Two or more independent refrigeration circuits where the condenser of one
system rejects heat directly to the evaporator of another.
Chlorofluorocarbons (CFCs)
Halocarbons containing only chlorine, fluorine and carbon atoms. CFCs are
both ozone depleting substances and greenhouse gases.
Climate change
Climate change refers to a statistically significant variation in either the mean
state of the climate or in its variability, persisting for an extended period (typically
decades or longer). Climate change may be due to natural internal processes or
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