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SUPPORT voices
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 understanding theoretical and practical aspects of the industry. I will endeavour to enlighten. We are going back to basics as I have questions coming in that indicate that the basic understanding necessary to work in industry is not in place.
Sipho: Mr Grant, could you please help us with an understanding of pipework insulation? How do we use this in air conditioning? Is it important to use glue? Thank you.
Hi Sipho, yes, I can help. We are speaking about the insulation of tubing for copper piping, being a foamed insulation tailored to prevent condensation in copper piping on air conditioners. The insulation is a flexible, elastomeric nitrile closed-cell foam insulation designed to protect pipes from heat loss and condensation. It ' s commonly used in air-conditioning and refrigeration systems for small to medium-sized pipes, improving energy efficiency and preventing moisture buildup.
There are different types on the market, the solid type that is slid over the tubing. The slip-on method of installation is used when you can insulate new piping before an installation. You can cut the insulation open for installed piping or use the zip type.
You will need the correct size armour flex, adhesive, good adhesive brushes and a sharp utility knife. Apply insulation only when the pipes are clean. Since rubber insulation, a closed-cell rubber, is
flexible, it will follow bends in tubing and can be slipped right over bent tubing, 45 ° sweat elbows, 90 ° sweat elbows and couplings.
GENERAL GUIDELINES
• Always use tools that are in good condition
• Only apply insulation to clean pipes at room temperature
• Never stretch the insulation; it is in fact better to compress the insulation slightly
• Try using insulation sections that are as long as the piping being insulated
• Allow some gap between piping; this allows for air circulation, which will serve as an additional safeguard against possible condensation. This is particularly applicable in hot, humid climates.
RACA Journal I January 2026
Yes, Sipho you must use glue as all of the insulation joints must be properly sealed. This is called a‘ vapour barrier’ and minimises heat transfer and controls condensation. Should condensation be allowed to enter the joints, corrosion may occur in addition to water dripping, causing possible water damage.
Ultraviolet radiation( the sun) degrades the insulation material, causing the insulation to break down into a powder and ultimately causing failure of the insulation. When using insulation outdoors, the insulation must be protected either by trunking or painting. Use paint in accordance with the insulation manufacturer’ s instructions. With regards to double insulation, stagger the side and end joints. Do not compress the piping insulation at columns, duct hangers, etc. The maximum allowed is 10 % compression in order to maintain the thermal efficiency. In addition, condensation may occur where the insulation is compressed.
CONSTRUCTING 90 º ELBOW At times, it may become necessary to construct 90 º elbows to fit over existing bends. In order to form a 90 º elbow, simply cut through the insulation at 45 º. Reverse the position on one side to form the elbow. Next, cut open the inside wall of the elbow, and the split-open elbow will fit over the tubing. Apply approved contact adhesive to the slit open portion and join by pressing the seams together. Apply adhesive and join together the corners of the elbow in the same manner. Finally, one can apply adhesive to the butt ends and seal.
EXISTING PIPEWORK When working with existing refrigerant pipework, one can use zip-type insulation. Should this not be available one can, using a sharp utility knife, slit straight down the length of the insulation.
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