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GRANT LAIDLAW
Grant Laidlaw is currently the owner of the Air Conditioning and Refrigeration Academy (ACRA) in Edenvale.
He holds a Bachelor of Business Administration and an associate degree in educational administration. He
has a National Technical Diploma and completed an apprenticeship with Transnet. He has dual-trades status:
refrigeration and electrical. He has been involved with SAIRAC for 17 years and has been a Johannesburg
committee member for the past eight (chairman in 2011 and 2012) . Currently he is the treasurer
(Johannesburg council) as well as president (national council).
REFRIGERANTS IN
COMMERCIAL REFRIGERATION
By Grant Laidlaw
Chris asks: Grant,we are beginning to see a lot of R290 in
the commercial refrigeration space and in particular the cold
drink type fridges. We were wondering, what changes to
tooling and basic procedures do we need to make as this is a
problem for us. Any advice would be appreciated. Also, are
we allowed to transport these new flammable refrigerants
in our vehicles? Again, what additional procedures do we
need to implement a professional driving permit (PDP)?
As equipment may only use 150g of hydrocarbons is this
really viable for air conditioning systems or only for larger
refrigeration systems?
H
Many people ask for assistance in the understanding of theoretical and
practical aspects of the industry. I will endeavour to enlighten.
Grant Laidlaw looks into
R290 in the commercial
refrigeration space.
i Chris, let us begin with the tooling, yes there are of course
some changes necessary.
Some standard tools and equipment, including gauge
manifold sets, can be used safely with flammable refrigerants.
Although, South Africa is still in the process of updating the
national standards pertaining to Hydrocarbons. Looking at the
English and European EN Codes we find the following: Avoiding sparks, good ventilation and no leakage are key
points to avoid a dangerous situation. When working with
A3 refrigerants, use a leakage detector and remember
that the vacuum pump, ventilation fan, recovery unit and
leak detector will need to be suitable and not constitute an
ignition source.
Safety procedure for the work area where HC systems
are being serviced: As far as the tooling is concerned let us begin with vacuum
pumps. The best option is to use vacuum pumps approved
for use with A2L, A2 or A3 (flammable) refrigerants. Having
said that, at the moment it is difficult to source these pumps
from our local suppliers. This situation will improve as the
market develops.
•
•
•
There must be no source of ignition (compressor contactors,
klixons, electrical connections) within 3m of the system.
The area must be well-ventilated.
The area must be monitored with a hydrocarbon leak
detector.
A3 are refrigerants with a higher flammability risk than A2L-
refrigerants. The main difference is that a relatively weak spark
can ignite a flammable mixture. Static sparks typically occur
from clothing, poor electrical earthing, or lighting an oxy-
acetylene torch.
www.hvacronline.co.za
TOOLING
What if a vacuum pump approved for flammable
refrigerants is not available?
Vacuum pumps with brushless motors can be used if the pump
is switched on by an external power source and not by the on/off
Continued on page 53
RACA Journal I February 2020
51