Beyond the surface: the unseen world of insulated panels

By Eamonn Ryan

Often overlooked, insulated panels are complex marvels of engineering, silently safeguarding everything from fresh produce to critical data.

Insulated panels, often called sandwich, composite or structural insulated panels, are far more complex than they appear. While they might look similar across suppliers, their configurations and material compositions vary significantly. Understanding these differences requires specialised knowledge.

In the cold chain, insulated panels are critical for maintaining temperature separation, reducing the energy demands on refrigeration systems. Imagine trying to cool a steel shed exposed to the midday sun—panels make this far more efficient by managing heat load.

While commonly associated with produce storage, their applications extend across the cold chain: cold and freezer rooms, food production and preparation facilities, abattoirs, medical rooms, growing environments, display fridges and transportation. Essentially, they’re vital wherever controlled conditions are needed to prevent product decay and ensure hygiene.

South Africa has seen a boom in cold storage and distribution centres, attracting international investment and higher standards. This growth benefits local manufacturers who have embraced technology and global standards, pushing boundaries with facilities featuring walls up to 38m high in some cases. The e-commerce surge has also boosted the transportation sector, driving demand for these panels in home delivery services.

At its core, an insulated panel is simple: a core material ‘sandwiched’ between two metal ‘skins’. In South Africa, production typically involves bonding pre-cut blocks to facings or ‘foam-in-place’ injection, where the core material expands to fill a cavity.

However, the devil is in the detail. Both core and skin materials come in various forms, directly impacting the final product’s quality. Panel thicknesses range from 25mm to 300mm, but density is also crucial for thermal properties. Skins, from 0.25mm to several millimetres’ thick, can be composites of different metals. Lower quality can lead to premature corrosion or compromised structural integrity. Beyond protecting the insulation, skins offer weather protection (especially from the harsh South African sun), hygienic surfaces and fire resistance, thanks to various coatings.

Fire risk ratings and optimal panel thickness/core choice based on application and geography are extensively covered in industry resources and online studies.

 

Installation and joining techniques

Wall panels can be freestanding or interlocked using various joining techniques or installed with full frame support.

They can also serve as wall cladding on existing concrete structures. Ceiling panels typically rely on wall panels for support, supplemented by hangers or steel cables. Both wall and ceiling panels come in different span lengths, with local production limited primarily only by transport capabilities. Reputable manufacturers provide guidelines for best installation practices, and often do it themselves.

A key, supplier-dependent feature is the panel joining method, which can involve unique locking designs, simple dovetails, direct insulation engagement with skin overlaps, or separate extrusion systems.

Insulated panels have a life expectancy of up to 30 years. South Africa offers various core materials, including special formulations from international suppliers. Detailed pros and cons of each material, such as degradation rates or liquid permeability, are available from industry associations.

Common core materials include:

• Expanded Polystyrene (EPS): ‘Bead boards’ are produced by expanding and bonding polystyrene beads in three densities. EPS degrades with prolonged sun exposure and requires compatible adhesives and sealants.
• Phenolic foam: Manufactured from phenol formaldehyde resin, it’s available in open or closed cell forms. It needs protection from prolonged sun and water exposure and is suitable for interior wall sheathing, both above and below ground.
• Polyisocyanurate (PIR) and Polyurethane (PUR): These are formed by chemical reactions that create tiny air cells filled with refrigerant gases. They require protection from prolonged water and sun exposure and must be covered with fire-resistant material indoors.
• Rockwool: Also known as stone wool or mineral wool, this material is derived from rocks and minerals.

It excels at sound and heat blocking and is often chosen for fire resistance, withstanding 1 000°C heat. However, it’s a brittle structural material and needs a matching supporting structure.

 

Factors for choosing the right insulation

Selecting the appropriate insulation product project-specific factors, as each facility typically has unique requirements:

• Facility/room size: Dependent on space needs and traffic flow
• Product/process type: The nature of what will be stored or processed
• Product volume: The quantity of product entering and leaving
• Processing versus storage needs: Whether the primary function is processing or long term storage
• Product entry/exit temperature: The temperature at which products enter or leave the process line
• Required storage temperatures: Specific temperature ranges needed (pull down, chill, freeze)
• Door sizes: Larger doors can significantly impact heat transfer

Diverse applications of insulated panels

Beyond the cold chain, insulated panels have evolved into versatile components for complex building systems. They are widely used as an alternative, modular construction solution, designed and manufactured off-site for rapid, effortless on-site erection. Their applications extend to:

• Houses (high-end and low-cost)
• Data centres
• Chemical storage areas
• Clean rooms
• Laboratories
• Hospitals
• General plant rooms
• Breweries
• Shipping
• Petrochemicals
• Mining
• Manufacturing
• Toilet and shower facilities
• Entertainment venues
• Portable facilities
• Flooring solutions
• Agriculture

Panel technology for cold stores

Kingspan Insulated Panels, thanks to its Isocab brand, is a global leader in providing high-performance insulated panels crucial for the cold store sector. Its commitment to innovation and sustainability directly addresses the critical need for energy-efficient solutions in temperature-controlled environments.

Michel van Helm, MD for Western Europe and Africa at Kingspan, says Kingspan’s insulated panels and Isocab are at the forefront of their offerings, including a focus on the cold storage sector in markets like Africa. A cornerstone of their panel technology for cold stores is QuadCore foam. This proprietary, self-blended foam offers significant advantages over standard PIR insulation:

• High levels of fire performance: QuadCore provides enhanced fire resistance, a critical safety factor in large industrial and storage facilities
• High thermal efficiency: Its advanced insulation properties lead to better temperature control and reduced energy consumption, which is paramount for cold storage facilities
• Logistical advantages: Thinner panel profiles and reduced screw requirements simplify installation and can optimise space within cold stores

“These characteristics make Kingspan and Isocab’s QuadCore panels ideal for a range of applications beyond just cold storage, including industrial buildings, warehouses, logistics facilities and data centres, all of which require precise climate control,” he says.

Kingspan’s overarching ‘Planet Passionate’ programme drives the development of low embodied carbon (LEC) products. For their panels, this translates to incorporating recycled content in steel, significantly minimising their overall carbon footprint.

Recognising that buildings account for a substantial 37% of global carbon emissions, primarily from heating and cooling, Kingspan’s integrated approach directly tackles this challenge. By combining high-performance insulated panels with airtightness solutions, they effectively minimise the energy required for climate control within cold stores, leading to substantial reductions in operational carbon emissions.

Van Helm adds: “Kingspan and Isocab employ a ‘best fit for purpose’ approach to insulation materials for its panels, offering a diverse range including PIR and mineral wool. This ensures that the optimal solution is selected based on specific performance requirements, catering to the varied demands of cold store construction while prioritising thermal efficiency.”

Selecting appropriate insulated panels for cold storage facilities requires careful consideration of several key factors. These systems are crucial for maintaining precise thermal and atmospheric control, ensuring product protection and hygiene in environments like freezers, coolers and food processing plants. A range of panel types are available, including Polystyrene (EPS), Polyurethane (PUR), Polyisocyanurate (PIR), Phenolic, Rockwool and Mineral Fibre. The decision-making process should prioritise durability, cost- effectiveness, fire performance, thermal efficiency and vapour tightness.

 

Fire safety and insurance considerations

The fire performance of insulated panels is a paramount concern, particularly given past incidents involving combustible materials. Buildings utilising certain types of sandwich panels, especially those with polystyrene cores, have been associated with significant fire losses in the food industry. This has led to heightened scrutiny from insurers and, in some cases, a reluctance by firefighters to undertake internal suppression due to safety risks.

While non-combustible panels exist, featuring core materials like mineral foams or fibres, even these may contain small amounts of combustible adhesives. To mitigate fire risks, several strategies can be employed:

• Fire breaks: Incorporating sections of non-combustible panels within areas of combustible panels
• Alternative materials: Opting for inherently non-combustible or less combustible panel materials
• Sprinkler systems and fire prevention planning: Implementing these based on a Rational Fire Design (RFD) that adheres to relevant standards (for example, ASIB or SANS in South Africa). This approach can lead to strategic sprinkler installations in high-risk zones and potentially reduce overall costs through compartmentalisation

Beyond material choice, the amount of smoke released during a fire is another critical aspect. Panels with low smoke release ratings are preferred to minimise harm to occupants, the surrounding community and the environment.

Independent certifications are valuable indicators of a panel’s fire performance, as these panels undergo rigorous testing. Some facilities prioritise passive fire protection strategies, focusing on panel components that inherently resist fire spread, to minimise potential downtime compared to active systems like sprinklers, which can still lead to prolonged operational halts.

 

Energy efficiency

Insulated panels are fundamental to the energy efficiency of a cold store. They effectively reduce heat ingress through walls and ceilings, provide a crucial vapour barrier to limit moisture penetration, and create a secure, hygienic enclosure. These functions are directly linked to maintaining the desired internal temperature with minimal power consumption. Thicker insulation generally translates to lower heat gain and, consequently, reduced energy usage. While the initial capital expenditure for thicker panels may be higher, the long-term savings in running costs often justify this investment.

When evaluating thermal performance, two key metrics are important:

• U-value: This measures the rate of heat loss through a specific thickness of a building element. A lower U-value indicates better insulation and less heat gain
• R-value: This represents a material’s ability to resist heat transfer at a given thickness. A higher R-value signifies superior insulating properties

Advances in panel composition mean that thinner panels can now achieve impressive thermal performance, maximising storage space within the cold store.

 

Warranties and long-term reliability

The longevity and performance of insulated panels are supported by manufacturer warranties. As product quality continuously improves across various panel types, warranties serve as a crucial differentiator in the market. A comprehensive, long-term warranty signals a manufacturer’s confidence in their product’s structural and thermal performance. It is essential for operators to thoroughly understand the terms and conditions of these warranties, as some may become void if panels are used in applications beyond their intended purpose. Prioritising suppliers who offer extended warranty periods provides peace of mind and safeguards against unforeseen capital expenditures in the future.

References:

1. The Global Cold Chain Alliance (GCCA)
2. FM Approvals
3. ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers
4. Africhill
5. Dalucon Refrigeration Products
6. Isowall
7. Kingspan
8. Panel World
9. Precool Manufacturing
10. Rigifoam
11. Science Direct
12. Thermal Insulation Products and Systems Association (TIPSASA)

 

 

Panel builder programme empowers local builders Supplied by Schneider Electric By simplifying operations, fostering growth, and embracing innovation, the mySchneider Panel Builder Programme in South Africa helps panel builders remain competitive in an ever-evolving market. The programme is a global initiative launched in South Africa in 2021. It is an interactive and intuitive platform that provides panel builders with certifications and specialised training, tailored to the industry segments they specialise in and customised for their respective industry segments, ensuring relevance and value. “Our primary goal is to equip panel builders with the right competencies and expertise to position themselves as specialised partners in their target markets. This helps them stay top-of-mind with end-users,” says Patsy Mboumba, channel marketing specialist at Schneider Electric South Africa. She explains that the overall objective of the panel builder programme is to assist panel builders to grow their businesses by becoming specialised, competitive partners. “This is more than a business initiative; it’s a partnership. We are dedicated to creating opportunities that benefit both Schneider Electric and our partners, ensuring long-term success for everyone involved,” Mboumba says. She notes that the programme has been recognised globally with a five-star rating for partner success, which illustrates that it is working well and achieving its goals of helping to enrich its partners. “This rating reflects the effectiveness of our partner- centric approach, setting Schneider Electric apart as a company that prioritises the success of its partners alongside its own,” Mboumba adds,   Digitisation and innovation Mboumba adds that the digitisation aspect of the mySchneider panel builder programme is designed to support panel builders to become more than just hardware providers, but also data and analytics partners for their customers. This aligns with the company’s focus on enabling digital transformation. By leveraging connected solutions, panel builders can integrate panel data with software to deliver actionable insights to their customers. “This ability to transform raw data into valuable insights allows panel builders to offer a comprehensive value proposition. End-users can better understand their power usage, improve efficiency and make data-driven decisions,” says Mboumba. In addition to the focus on digitisation, Schneider Electric is also expanding the programme to include a services component. This will see the introduction of the ‘power upgrade’ badge to the programme, which will enable panel builder partners to enter the services business. “This services aspect includes maintenance and ongoing services for the units as well. By adding this service component, panel builders can position themselves as full-service providers,” says Mboumba.  “Since the launch of the programme in South Africa, it has grown significantly, and we currently have more than 100 panel builders participating in this initiative. The introduction of the service component is yet another key part of the programme’s evolution,” she says.

 

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