Flammability Standards
and 2L Refrigerant Introduction
B
y now we are all aware that
programs to thoroughly investigate the
a degree of flammability or to accept a
regulation of fluorinated
performance and reliability of these
higher GWP in order to maintain non-
refrigerants is here in
alternatives and to optimise syst em
flammability. Central to this choice is how
Europe through the
performance based on the properties of
to meet the GWP regulatory requirements
the new fluids.
whilst maintaining a high degree of safety?
Mobile Air Conditioning (MAC) Directive,
for automotive air conditioning, or the
F-Gas Regulation for all other refrigerant
applications.
As with many of the higher GWP products
they are to replace, for example R-404A,
many of the new alternatives proposed
In some circumstances, the choice is made
for us by the regulations. For example the
MAC directive requires use of refrigerant
GWP below 150 and with the exception of
Over the last few years, the chemical
are blended HFCs. The building blocks
manufacturers have been looking to
for these alternatives include the
develop reduced GWP products that are
hydrofluoroolefins (HFOs) as well as the
capable of meeting the requirements of
more familiar lower GWP fluids such as
Similarly looking ahead to alternatives for
these regulations and which maintain the
R-32 and R-152a.
R-410A in smaller (<3kg charge) single-
high levels of safety and efficiency we have
come to expect from hydrofluorocarbon
refrigerants. Here, Stuart Corr, techno
commercial director of refrigerant gases
manufacturer and supplier, Mexichem,
discusses how the issue of refrigerant
flammability relates to the use of reduced
GWP products.
All of these components are flammable,
falling into the ASHRAE 2 2L safety
categories. Whilst they can be blended
with non-flammable components in
order to achieve non-flammability,
for the majority of air conditioning
and refrigeration applications, it is an
unfortunate fact that the lowest GWP
We are in a position where the
products will tend to be flammable to a
refrigeration and air conditioning
degree, mostly falling within the ASHRAE
industries have a number of options
2L category.
available to them across the range of
application sectors and many of the
equipment manufacturers have active
64
PECM Issue 20
CO2, there are no viable non-flammable
candidates.
split a/c systems, the F-Gas Regulation
imposes a GWP limit of 750 and again
there are no viable non-flammable
candidates identified to date with R-32,
and blends based on R-32, coming to the
fore. The first step towards introduction
of a refrigerant is to determine the
flammability and toxicity classification for
the fluid. This is most commonly through
the internationally recognised ASHRAE
classification system (figure 1). Whilst this
process is essentially complete for the MAC
The industry is then faced with a choice:
sector, the stationary applications are more
to use the lowest GWP fluid and accept
complex.