www . refrigerationandaircon . co . za RACA Journal I July 2023 41
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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 over two decades and served on the Johannesburg committee as chairman and was also president between 2015 and 2018 . Currently he is the SAIRAC national treasurer .
WELCOME TO THE
SOLUTIONS PAGE
By Grant Laidlaw
Many people ask for assistance in the understanding of theoretical and practical aspects of the industry . I will endeavour to enlighten . I am going back to basics as I have questions coming in which indicate that the basic understanding necessary to work in industry is not in place .
Jannie asks : “ I have often wondered why do we fit insulation to pipes on split units , does it really make such a difference when looking at costs , trunking looks better anyway ? On larger air conditioning systems what other types of insulation can we use ? I would like a better understanding around this subject .”
Hi Jannie , let us start by asking : ‘ Why insulate ?’
Insulation is used to prevent heat loss or heat gain , to control noise ( acoustic insulation ) and to prevent condensation on cold surfaces ( the vapour barrier ). Although its primary purpose is economic , insulation also provides more accurate control of process temperature and protection ( health , safety and comfort ) of people . We need our air-conditioning and refrigeration systems to operate at maximum efficiency levels especially as our electricity supply is so limited . Remember , some buildings run hundreds of units , and the energy savings can therefore be significant .
Insulation is the energy stabiliser – it keeps the wanted energy in and the unwanted energy out . It protects , controls and saves .
Building and industrial safety standards must be adhered to when choosing the type of insulation products , vapour barriers , coverings , coatings and / or claddings . Knowledge of building and industrial fire standards is extremely important . One must know where and for which application combustible materials may be used . The rules for that building / room / industry apply to all materials used therein .
The suppliers of insulation materials supply data sheets containing the thermal , acoustic ( where applicable ), fire and
ACRA safety properties of their material , as well as any handling , storing and installation instructions .
Thermal and acoustic insulation is used externally and internally on ducts . Pipe-work is insulated to save energy , prevent condensation and in some applications to reduce noise . Understanding the basics of heat transfer is vital in understanding the subject of insulation .
In order to understand thermal insulation , it is necessary that we first understand the basic principles of heat transmission
“ Insulation is the energy stabiliser – it keeps the wanted energy in and the unwanted energy out .”
The fullyaccredited Air Conditioning And Refrigeration Academy .
www . refrigerationandaircon . co . za RACA Journal I July 2023 41