ASHRAE Journal - January 2020 - 56

COLUMN REFRIGERATION APPLICATIONS
Andy Pearson

Looking Back and Forward
BY ANDY PEARSON, PH.D., C.ENG., FELLOW ASHRAE

January is a good time for taking stock, looking back over what's been achieved and
looking forward to what is to come. 2020 has a particular signiﬁcance because it is the
year that the Montreal Protocol restriction on the use of HCFCs such as R-22 reaches
100%-a complete ban-for developed economies.

ISTOCK CLAUDIODIVIZIA

Looking back over the Montreal Protocol it is inter10 years became widespread in their use. So we had
esting to note that the original text was published
CFCs for 60 years and they disappeared in a further
in 1986, the year that I started work full time in the
six, HCFCs for 40 years with a 20-year phasedown and
refrigeration industry, and was signed the following
HFCs for 25 years before their restriction started. On
year and subsequently ratiﬁed by all the members of
the face of it, this shortening of the time horizon does
the United Nations as well as other entities such as
not bode well for the HFOs. It is true that their develthe Holy See and the European Union. The original
opment has addressed each of the questions asked of
text only required a reduction to 50%
previous generations of refrigerant
Janus didnÕt know where to look.
of baseline consumption for CFCs but
so that they offer no threat to the
this quickly transformed into a comozone layer and have a global warmplete phaseout and was followed by the
ing potential similar to that of CO2,
phaseout of HCFCs.
but doubts remain about long-term
Looking further back, the introducreliability, effects on the environtion of CFCs to the market took about 40
ment and, perhaps most importantly,
years, from the initial launch of R-12 in
energy efﬁciency.
1930 to the development of R-502 in the
Looking forward, it seems likely that
late 1960s. This period was somewhat
efﬁciency will be the dominant deterextended because of the Second World
minant in refrigerant choice over the
War, when R-12 was reserved for military
next few years. It seems unlikely that
uses and the domestic systems of that time continued to
the challenges presented in this respect can be resolved
use methyl chloride until the war was over. So it took 40
simply by putting new ﬂuids into old system designs.
years to bring CFCs in but they only had 19 years of use
When considered on a "source-to-sink" basis most "notbefore the eight-year phaseout started. HCFCs came in
in-kind" technologies fare less well than any of the sysafter the war and were included in the Montreal phasetems using ﬂuorinated gases so they also don't seem to
out lists in the late 1980s.
offer a complete solution.
The replacement for CFCs, the HFCs, fared less
We have come a long way in the last 30 years and have
well. Introduced from about 1990 it took only 15 years
achieved a great deal, but there is a lot to be done. The
for concerns to be raised about  global warmquestions facing us are getting harder, and the time
ing potential and within a further 10 years they had
available to answer them is less. I'll leave you with this
been added to the Montreal phasedown mechanism.
question to consider: Will HFOs have a longer applicaInterest in their replacements, the HFOs, dates back
tion life than the CFCs that they are replacing?
almost to the introduction of the HFCs but they started
Andy Pearson, Ph.D., C.Eng., is group managing director at Star Refrigeration in Glasgow, UK.
to receive signiﬁcant interest around 2005 and within
56

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