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

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Retrofitting
• Upon evaluation of a system that requires major repair and
is close to the end of its technical/economical life, consider
replacement if it is more cost effective than retrofitting.
• The safety and environmental properties of alternative refrigerant
to be used, such as flammability, toxicity, ODP and global
warming potential shall be considered.
• Include in the assessment the compatibility of components
and materials in the system, such as elastomers and oil. Also
components like sight glasses and oil separators must be
checked for suitability.
• Assess and examine the operating conditions of the system and
determine the service and its operational history.
If necessary, consult the equipment manufacturer for the recommended
alternative refrigerant and lubricant for the system.
Use of drop-in refrigerants
The phasing-out of ODS refrigerants, and in particular, CFCs in
the RAC sector, has led to the development of new refrigerants
that are often claimed to be direct replacements for the original
ODS refrigerants. These refrigerants vary in compositions; some
are synthetic fluorocarbons, others are natural refrigerants such as
hydrocarbons (HCs), some are single substances, others are blends.
However, it is important to thoroughly investigate any particular
refrigerant that is being considered for use, to ensure that it is a
suitable replacement for the situation under consideration, and that
those working with the refrigerant are fully aware of its implications.
The following should be carried out:
• Check the Material Safety Data Sheets (MSDS) to understand its
safety characteristics
• Request relevant information related to the substance from the
manufacturer of the substance
• Find out whether or not the existing mineral oil needs to be
replaced or not
• Technicians should also look for training on the proper handling
of these new refrigerants.
Hydrocarbons are known to be flammable, although there are
certain concentrations that must be reached prior to explosion
if ignition occurs. That is why education and information
dissemination is very important. Several developing countries are
implementing, with the support of UNEP and other implementing
agencies, training programmes in good practices, and the use
of drop-in refrigerants among other topics are covered in such
courses.
General retrofitting procedures
A generalised procedure should be followed when retrofitting
any refrigeration system with an alternative refrigerant. However,
there may well be specific variations according to the particular
characteristics of the system under consideration and the
refrigerants involved. See the interactive diagram to see how this
flow works for a retrofitting of CFC refrigeration equipment.
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