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Cold storage panel installation is a core process in cold storage engineering, and the details of the construction directly determine the insulation effect, energy consumption, and service life of the cold storage. Many cold storage facilities experience problems such as cold leakage, frost formation, deformation, and water leakage later on, and 80% of these are caused by improper installation.   1. Pre-construction preparation. Verify the panel parameters in advance, confirm the panel thickness and flame retardant rating according to the temperature control requirements of the cold storage, and check the panel surface for dents, delamination, and damage. At the same time, clean the construction ground, ensuring it is flat, dry, and free of debris. For low-temperature cold storage, a moisture-proof layer must be laid in advance to prevent the floor from stretching the panels due to freezing. Prepare specialized sealant, angle aluminum, and pressure strips in advance; do not use ordinary household sealing materials.   2. The installation of the base plate and walls requires control over flatness and sealing. First, locate and mark the installation points of the panels accurately, ensuring overall horizontal and vertical alignment. When installing the bottom panels, ensure even gaps are left, and apply a full layer of special low-temperature sealant to all joints to prevent hollow gaps. This is a crucial step in preventing cold bridging and condensation. After the wall panels are assembled, reinforce them with strips and angle brackets immediately, paying special attention to sealing edges and corners to prevent cold air leakage. Continuously check verticality throughout the installation process; deviations must be kept within specifications.   3. Top panel installation is the most error-prone stage. Top panel joints must not have upward-facing gaps. All joints must face inwards, and the sealant must be full, dense, and free of breaks or air bubbles. Reinforcing brackets must be installed at load-bearing locations on the top panels to prevent them from being suspended and deformed or detached under long-term stress. Avoid drilling holes for pipes; ensure all openings are properly sealed to prevent cold air leakage.   4. Pay close attention to finishing details and acceptance procedures. Irregularly shaped areas such as doors, vents, and access panels require meticulous sealing to prevent air leakage from dead corners. After all panels are installed, apply a final coat of sealant, inspect all seams and edges, and repair any omissions or defects. Finally, conduct a no-load cooling test to observe for frost, water seepage, abnormal temperature differences, etc. Once everything is confirmed to be in order, the project is considered complete and ready for handover.   In summary, proper material selection, standardized splicing, and meticulous sealing are essential for cold storage panel installation. This not only improves the insulation stability of the cold storage and reduces future energy consumption but also minimizes rework and rectification, enhancing the project's delivery reputation.

Cold storage insulation materials are currently mainly divided into three types: PU polyurethane, PIR modified polyurethane, and EPS polystyrene. These three differ significantly in insulation performance, price, and suitable application scenarios. In practical applications, the appropriate material can be selected based on specific needs.   PU polyurethane sandwich panels are the preferred material for general cold storage. With a thermal conductivity of 0.022-0.024 W/m·K, high closed-cell rate, and low water absorption, their thermal insulation and sealing performance is superior to ordinary insulation panels. The panels have high structural strength and are not easily deformed. The flammability rating can reach B1 (with added flame-retardant formulation), and is mostly B2 under normal operating conditions. The long-term applicable temperature range is -35℃ to +10℃, suitable for most commercial cold storage conditions, including fresh-keeping warehouses, low-temperature warehouses, and general frozen warehouses. The panels have tight joints, effectively reducing cold bridging and leakage problems. With outstanding overall cost-effectiveness, it is currently the most widely used cold storage insulation material on the market. The market price is moderate, suitable for conventional cold chain projects with a controllable budget.   PIR modified polyurethane sandwich panel, specifically designed for high-end low-temperature cold storage.  Its thermal conductivity reaches 0.019-0.022 W/m·K, offering slightly better insulation performance than PU panels. It boasts superior flame retardancy, is less prone to producing molten droplets during combustion, and consistently achieves B1 flame retardancy rating. It also exhibits better high-temperature resistance. With a long-term operating temperature range of -55℃ to +15℃, it shows minimal insulation degradation under ultra-low temperature conditions. The panel exhibits stronger anti-aging properties, making it suitable for high-end projects with stringent fire safety standards, such as blast freezers, ultra-low temperature cold storage facilities, and medical cold chain warehouses. While offering excellent insulation and low-temperature stability, its main drawback is its higher cost, exceeding that of ordinary PU panels by 15%-30% per square meter. It is more suitable for critical projects with high safety and temperature control requirements.   EPS polystyrene sandwich panel, an economical alternative for cold storage. EPS insulation panels are lightweight, inexpensive, and easy to install, making them suitable for cold storage facilities with limited budgets and less stringent temperature requirements. Its thermal conductivity is 0.038–0.041 W/m·K, indicating weak thermal insulation capabilities and poor moisture and frost resistance. Long-term use at low temperatures can lead to water absorption, deformation, and decreased insulation performance. It is only suitable for fruit and vegetable preservation and ambient/constant temperature workshops, and is not recommended for low-temperature or frozen storage.   In summary, cold storage insulation materials should be selected according to specific needs. PIR insulation panels are preferred for high-end low-temperature or ultra-low-temperature cold storage, PU insulation panels are suitable for conventional commercial high and low-temperature cold storage, and EPS insulation panels are suitable for ordinary preservation and constant temperature scenarios.  

The service life of sandwich panels is primarily determined by the facing material, facing coating, core material type, operating environment, and subsequent maintenance; lifespan varies significantly depending on the materials used and the application scenario.   The facing material is a key factor determining service life: in standard inland environments, panels featuring an Al-Zn (aluminum-zinc) alloy substrate (AZ100/AZ150) with a PE (polyester) coating typically last 12–15 years, whereas those with a PVDF (fluorocarbon) coating offer superior weather resistance, extending the lifespan to 20–25 years. In highly corrosive environments—such as coastal areas with salt spray or chemical industrial parks—standard Al-Zn panels are prone to rusting; in these cases, 304 stainless steel substrates with PVDF coatings are recommended, offering a service life of over 25 years with proper maintenance.   Performance also varies based on the core material: PIR and rock wool sandwich panels offer structural stability; closed-cell PIR sandwich panels provide excellent moisture and aging resistance, maintaining their shape over long-term use. Conversely, EPS sandwich panels are prone to shrinkage and degradation in high-temperature or humid environments, which can shorten their service life.   Additionally, proper installation and regular maintenance can effectively extend the lifespan of sandwich panels. Avoiding impact, promptly repairing coating damage, and ensuring effective joint sealing help minimize rust and core material damage. With appropriate material selection and maintenance, high-quality sandwich panels can achieve a service life of over 30 years in certain applications.

The certifications held by a sandwich panel manufacturer serve as a key indicator of product quality, regulatory compliance, and corporate capability. Requirements vary depending on the application scenario, but the essential certifications generally fall into three categories: foundational management system certifications, product-specific certifications, and international export certifications.   Foundational management system certifications form the basis of compliant operations. Key certifications include ISO 9001 (Quality Management System), ISO 14001 (Environmental Management System), and ISO 45001 (Occupational Health and Safety Management System). These three certifications cover the control of the entire production process—ensuring consistent product quality and environmentally safe production—and serve as a basic threshold for domestic project procurement; without them, it is difficult for a company to guarantee product consistency.   Product-specific certifications are crucial for ensuring sandwich panels meet project requirements. Fire safety certification is paramount; products must comply with the GB 8624 standard and possess corresponding fire-rating test reports. For Class A non-combustible panels, additional fire-resistance limit test reports are required—a mandatory stipulation for commercial projects and industrial facilities. Next is Green Building Material certification; certified products receive priority in government-funded engineering works and green building projects, aligning with current policies on building energy efficiency. Additionally, for specialized environments such as clean rooms and cold storage facilities, specific certifications regarding cleanliness levels and thermal insulation performance are required.   International export certifications are essential for expanding into overseas markets. Exports to the EU require CE certification based on the EN 14509 standard, covering comprehensive requirements for product performance and safety. Exports to the US and similar regions may benefit from FM certification to enhance product recognition, while exports to Australia require AS1530 and Code Mark certifications. Certain regions also mandate compliance with local standards—such as Russia's GOST certification—to ensure smooth customs clearance and adherence to local engineering requirements.   In summary, a high-quality sandwich panel manufacturer must hold foundational system certifications, product-specific certifications, and relevant international certifications. When procuring materials, it is essential to verify the authenticity and validity of these certificates to prevent project acceptance issues caused by incomplete qualifications.  

Sandwich panels are typically constructed by bonding two layers of facing material—such as color-coated galvanized steel sheets, aluminum sheets, or fiberglass cloth—with an insulating core. Depending on the core material, they are classified into PU, PIR, EPS, and rock wool sandwich panels. A comparative analysis of these types follows. Performance iIndex PU Sandwich Panel PIR Sandwich Panel EPS sandwich panel Rock wool Sandwich panel Thermal Conductivity（W/(m・K)） 0.022-0.028 0.018~0.023 0.038-0.042 0.040-0.048 Density(kg/m³） 36~45 kg/m³ 40~50 kg/m³ 10~18 kg/m³ 90~150 kg/m³ Hygroscopicity ≤ 3% ≤ 2% Low (closed-cell structure, water absorption rate ≤ 4%) High (porous structure, water absorption rate can reach 5%-10%) Fire Rating B2 B1 B2 Non-flammable (Class A), does not release toxic gases at high temperatures Sound insulation performance Moderate Moderate Lower High Weather Resistance Better (its UV resistance is superior to EPS, but still requires protection) Better than PU Poor (Subject to aging and deformation due to long-term exposure to ultraviolet rays) Excellent (resistant to high and low temperatures, anti-aging, unaffected by ultraviolet rays) Compressive / Flexural Strength Higher (with good toughness and strong impact resistance) Better than PU, more stable Medium (Susceptible to Impact Damage) High (strong in rigidity, but with high brittleness, prone to cracking) Cost Higher Highest Lowest Moderate   Based on the comparative analysis of the four types of core-material sandwich panels across various aspects: PIR sandwich panels offer the best thermal insulation and better fire resistance, delivering high overall cost-effectiveness, they are suitable for high- and low-temperature cold storage, blast-freezing facilities, cold-chain logistics warehouses, and EU-standard industrial plants. PU sandwich panels rank second in thermal insulation performance and are suitable for standard constant-temperature facilities, steel structure enclosures, temporary structures, and roofing or wall panels. EPS sandwich panels provide good thermal insulation at a low cost; being lightweight and easy to install, they are ideal for simple industrial buildings, temporary modular structures, construction site hoarding, and warehouses with lower specifications. Rock wool sandwich panels, distinguished by their superior fire resistance, are suitable for large shopping malls, office buildings, high-rise structures, hazardous chemical warehouses, explosion-proof workshops, and projects requiring Class A fire safety ratings.

Commercial projects typically encompass commercial factory buildings, cold storage facilities, shopping centers, logistics warehouses, office building envelopes, exhibition centers, and supermarkets. Selection requires a comprehensive evaluation of factors such as the sandwich panel's fire resistance, thermal insulation performance, operating environment, price, and lifecycle.   Fire safety requirements dictate the choice of materials: Class A non-combustible rock wool or glass wool panels are mandatory for high-occupancy areas (e.g., shopping centers, supermarkets) and high-rise commercial buildings (e.g., office buildings, exhibition centers). For cold storage and temperature-controlled warehouses, Class B1 PIR panels are the preferred choice; the specific core material type and thickness should be determined based on the building's temperature control requirements.   Insulation core materials are selected based on application needs: Rock wool sandwich panels (density ≥100 kg/m³) offer Class A1 fire resistance and excellent sound insulation, making them suitable for shopping mall facades, industrial plants, and pharmaceutical clean rooms. PIR sandwich panels offer the lowest thermal conductivity and superior insulation performance; their closed-cell core structure provides strong moisture resistance, making them the top choice for cold storage and cold chain warehousing. Glass wool sandwich panels feature outstanding sound absorption, making them ideal for spaces requiring noise reduction, such as stadiums and equipment rooms. EPS sandwich panels are suitable only for low-fire-risk applications, such as temporary auxiliary warehouses. Polyurethane-edged rock wool insulation sandwich panels combine fire resistance with thermal insulation, making them a cost-effective choice suitable for most commercial factory buildings.   Panel facings and coatings are selected based on the operating environment: For standard environments, Al-Zn (AZ100 or AZ150) substrates with PE (polyester) coatings offer a service life of 15–20 years. For corrosive environments—such as coastal areas exposed to salt spray or chemical industrial parks—304 stainless steel substrates with PVDF (fluorocarbon) coatings ensure long-term weather resistance and a service life of 25–30 years.   Comprehensive cost considerations involve evaluating raw material costs: construction and labor expenses, and long-term energy consumption and maintenance costs. Although sandwich panels with high-performance insulation cores may have a slightly higher unit price, their rapid installation significantly reduces labor and time costs. Furthermore, they entail minimal maintenance expenses and substantially lower building energy consumption during operation, yielding significant long-term energy savings and achieving the best total lifecycle cost.  

Watched masonry crews for years. Stacking blocks. Waiting for mortar to cure. Praying for dry weather. Then I oversaw a panelized build. Four riggers. One crane. Entire industrial shell sealed in five days. Traditional brick is dead for commercial logistics.   Velocity dictates project viability. Brick demands layering, plastering, and curing delays. Panelized steel structures bypass this entirely. Construction timelines drop 50 to 60 percent. Optimized sites hit a 70 percent reduction. Facility occupation happens months earlier. Capital starts circulating sooner.   Material unit cost is a trap. Analyze the dead load. Masonry dumps 180 to 250 kg per square meter onto your foundation. Sandwich panels sit at 12 to 15 kg. That delta dictates your concrete spend. Shallow excavation. Lighter structural framing. Total project cost drops 15 to 25 percent.   Thermal dynamics destroy brick. Matching a 100mm PU panel requires 400mm of masonry. Advanced cores hit 0.018 to 0.024 W/m·K. HVAC utility overhead plummets 20 to 40 percent. Perimeter footprint shrinks simultaneously. A 200mm brick wall steals usable interior floor space. A 50mm to 150mm panel hands that square footage back to the operator.   Lifecycle maintenance. Brick absorbs moisture. Thermal expansion cracks the joints. Masonry requires continuous repointing. Panel systems utilize galvanized steel skins. The rigid foam core never sags. Decades of operation. Zero maintenance. Specify panels. Build faster

Client called me three years ago. Brand new freezer facility. Compressors running blind, zero shutoff. Ice thick on the interior walls. Utility overhead bleeding him dry. The diagnosis was simple. Catastrophically underspecified panels. Wrong core. Inadequate thickness. Panel spec dictates compressor lifespan. Period. +5°C to +10°C: Chillers and Produce Baseline cooling. 75mm to 100mm panels. PU core functions perfectly here. 0.022–0.024 W/m·K thermal conductivity. Do not drop below 75mm. Efficiency falls flat. 0°C to -5°C: Chiller Rooms Phase change territory. Moisture becomes frost. 100mm is the strict minimum. Protect the thermal barrier. PU remains acceptable. -5°C to -18°C: Freezer Rooms Frozen protein. Seafood. Ice cream. 120mm to 150mm required. Switch to PIR immediately. 0.018–0.020 W/m·K. PU loses cost-efficiency here. 24/7 refrigeration cycles demand PIR density. Energy savings recover the upgrade cost fast. -18°C to -25°C: Deep Freezers Long-term bulk storage. 150mm baseline. Zero exceptions. High-risk facilities push directly to 180mm. EPS is permanently disqualified. -25°C to -40°C: Blast Freezers Vaccines. High-end aquatic products. Rapid temperature drops. 150mm to 200mm. Breaching -40°C pushes requirements to 250mm. PIR strictly mandatory. No alternative cores survive this thermal shock. Envelope integrity matters. Condensation destroys steel. Z100 galvanization rusts out under heavy washdowns. Specify Z150 minimum. Coastal exposure? Z275. Joint configuration is critical. Tongue-and-groove edges. Heavy sealant application. Micro-leaks destroy cooling efficiency. At Propanel (propaneltech.com), we match core, thickness, and steel gauge directly to your operating temperatures. Eliminate specification errors. Protect the compressors.

Masonry is obsolete for industrial scale. Watched crews lay brick for years. Months of structural delays. Pre-engineered buildings (PEB) eliminated that. One crane. Stacked panels. 10,000-square-meter facility completely sealed in weeks.   Factory-designed steel structures. On-site assembly. Clad in sandwich panels—twin steel skins bonded to a rigid insulation core. Unmatched velocity. Reduced dead load. But specification errors destroy projects. Here is the operational reality.   THE ADVANTAGES Velocity: Prefabricated components. Exact dimensions. Zero on-site cutting. Weeks instead of months. Labor overhead plummets. Revenue generation starts instantly. Dead Load Reduction: PEB structures shed 20 to 30 percent mass. Massive foundation savings. Less concrete excavation. Reduced site prep. Hard capital stays in your pocket. Thermal Dynamics: Integrated core. PU, PIR, or Rock wool. Heat transfer halts. HVAC demands drop 20 to 40 percent. 24/7 warehouse operations see massive utility reductions. Lifecycle Durability: Galvanized steel skins. Zero rust. Rigid cores never sag like fiberglass. Decades of operation. Minimal maintenance budget.   THE LIABILITIES Initial Capital: Outperforms basic single-skin metal sheeting, but demands higher upfront spend. Procurement stings. Utility savings offset this entirely, but initial cash flow must support it. Combustibility: EPS and standard PU burn. High-risk inventory or strict municipal codes demand upgrades. Specify PIR for surface charring. Mandate Class A1 Rock wool for absolute non-combustibility. Moisture Penetration: Compromised seals destroy R-values. Water breaches the core. Insulation fails. Cold storage applications suffer extreme frost buildup. Power bills spike. Zero Field Flexibility: Off-site engineering is absolute. Mid-project design changes equal financial disaster. Specifications must be flawless before manufacturing begins.   THE VERDICT Warehouses. Factories. Cold storage. PEBs with sandwich panels dominate here. Maximum clear span. Maximum speed. Extreme thermal efficiency. Do not specify if blueprints are unstable. Do not specify if procurement budget is the sole priority.

Watched too many cold storage projects collapse financially. Contractors chasing upfront savings. Specifying EPS to cut costs. Fast forward five years. Compressors running blind. Utility bills doubling. Initial savings vanish instantly. Over 15 years manufacturing panels at Propanel, I see this daily. Here is the actual math.   Foam dictates performance. EPS is fused white beads. Strictly budget grade. PU and PIR are industrial standard. Look at thermal conductivity. PU/PIR hit 0.018 to 0.024 W/m·K. EPS lags at 0.030 to 0.038. That delta is brutal. You need 200mm of EPS to match 100mm of PU. Double the wall thickness. Massive loss of usable interior floor space.   Procurement cost deceives buyers. EPS runs 30 to 50 percent cheaper. 80 to 120 RMB per square meter for 100mm EPS. PU commands 120 to 180 RMB. Calculate the operational overhead. A 200sqm facility with inferior insulation bleeds $3,000 to $6,000 annually in wasted electricity. Ten years of operation wipes out the procurement discount ten times over.   Fire ratings separate the materials. PU and PIR achieve B1. Surface charring. No dripping plastic. EPS tops out at B2. Highly combustible. Pharmaceutical audits will fail EPS instantly. Moisture absorption ruins R-values. PU and PIR are closed-cell. Zero water penetration. EPS absorbs ambient moisture. Wet foam acts as a thermal bridge. Frost builds up. Insulation fails completely.   The specification rule is absolute. Coolers above 0°C with tight budgets and zero fire risk? EPS functions. Sub-zero applications? Frozen protein or seafood? PU or PIR exclusively. Pharmaceutical sectors or strict fire codes dictate PIR. Zero exceptions.

Modular sandwich panels are composed of color steel and a core material. Their dimensions can be professionally customized according to engineering drawings. After receiving the panels, builders can directly assemble them on-site, maximizing construction time and saving labor costs, making them a top choice for construction contractors. Specific analysis is as follows:   1. Significantly shortened construction cycle. Modular sandwich panels are cut to size according to requirements and manufactured, eliminating the need for traditional plastering, masonry, and layered insulation construction. Walls, roofs, and ceilings are assembled as a single unit, and after assembly, they are directly sealed with adhesive, effectively shortening the overall construction period and helping contractors deliver projects ahead of schedule. This reduces equipment rental and labor costs, mitigating the risk of project delays. Especially in clean rooms of automotive and electronics factories, electromechanical and dust-free equipment installation can be carried out simultaneously, resulting in higher efficiency for cross-construction.   2. Controllable overall cost and reduced construction costs. Modular integrated sandwich panels combine insulation, fireproofing, enclosure, and dust-proofing functions. This eliminates the need for separate insulation layers, waterproofing layers, and interior plastering, significantly reducing the use of auxiliary materials and labor. Furthermore, the standardized panel specifications reduce wastage to below 3%, significantly lower than traditional on-site construction. Lightweight sandwich panels also lower the load on beams, columns, and foundations, reducing the amount of reinforced concrete used in civil engineering, thus compressing costs from the outset and helping contractors control budgets and increase project profits.   3. Simple construction and low labor requirements. Sandwich panels only require skilled installers for splicing and fixing, eliminating the need for multiple trades such as bricklayers and plasterers. In environments with labor shortages and rising labor costs, this facilitates personnel allocation and avoids construction delays caused by skilled worker shortages. Modular sandwich panels come with a full range of specialized accessories such as edge trims, corner pieces, and door and window finishes, allowing for direct on-site assembly.   4. Meets the specific needs of different factories with a high acceptance rate. Sandwich panels can use different insulation core materials, such as rock wool, PIR, and silica rock, meeting various requirements such as Class A fire resistance, B1 flame retardancy, and dust-free and anti-static properties. They are suitable for electronic clean rooms, automotive painting plants, and power battery factories. Furthermore, the sandwich panels come with factory testing reports, and all fire safety and final acceptance documentation is complete, significantly reducing the probability of rework and the associated costs.   5. Significant advantages in post-construction modification and maintenance. Sandwich panels are disassembled and reused with minimal disassembly damage, making them suitable for later factory renovations, expansions, or workshop area adjustments. Automotive and electronics companies frequently update their production lines; modular wall panels offer flexible assembly and disassembly, facilitating modifications. Contractors find it easier to secure maintenance and renovation contracts. Moreover, sandwich panels are moisture-proof and resistant to mold, resulting in low long-term maintenance costs, high owner satisfaction, and positive reputation for contractors, leading to future project expansion.   6. Lightweight and efficient transportation and handling. The lightweight nature of sandwich panels allows for short-distance transport by trucks and forklifts, saving time and reducing logistics and hoisting costs.   In summary, modular sandwich panels offer multiple advantages, including shorter construction periods, reduced costs, simple and rapid construction, and high acceptance rates. They perfectly meet the core needs of construction contractors to reduce costs and increase profits, making them the preferred building material for industrial plants.  

Automotive and electronics plants need to meet requirements for dust and explosion prevention, static electricity prevention, moisture control, and temperature control.   Different sandwich panels need to be selected according to different production areas within the workshop, as follows:   1. For power battery and electronic assembly workshops, we recommend high-density rock wool handmade panels with magnesium oxide edge sealing: The core material is basalt rock wool with a density ≥120kg/m³, double-sided corrugated steel plate covering + four-sided magnesium oxide sealing, A1 fire rating, fire resistance exceeding 60 minutes, fully meeting the fire protection requirements of new energy battery workshops and electronic workshops. The rock wool handmade panel is covered with a protective film, is dense and does not accumulate dust, is resistant to forklift scratches, and the protective film can be removed after assembly.   2. For temperature-controlled and temperature- and humidity-controlled clean workshops, we recommend PIR polyurethane sandwich panels: PIR sandwich panels have a thermal conductivity of only 0.023W/(m·K), excellent thermal insulation performance, a closed-cell rate higher than 95%, extremely low water absorption, and significantly better temperature control performance than other core material sandwich panels. Fire resistance reaches B1 flame-retardant level, suitable for electronic SMT assembly, automotive chip assembly, and temperature-controlled testing workshops for automotive parts.   3. Ultra-high precision clean rooms utilize silicon rock/aluminum honeycomb clean room panels: Silicon rock panels are Class A non-combustible, moisture-proof, and mildew-proof, with a dense surface that prevents dust shedding. Their cost-effectiveness surpasses that of aluminum honeycomb panels, making them suitable for clean room assembly of electronic and automotive modules. Aluminum honeycomb panels are lightweight, extremely flat, and possess excellent anti-static properties, but are more expensive. They are primarily used for ceilings and partitions in precision workshops for semiconductors and automotive radar, where large-span ceilings do not require dense joists. Both types of panels are easy to clean, corrosion-resistant, and suitable for clean rooms requiring high-frequency water washing, meeting ISO 7-8 clean room standards.   In summary, for high-risk production areas in automotive and electronics plants (batteries, painting, welding), Class A rock wool clean room panels with magnesium oxide edge sealing are preferred; PIR polyurethane sandwich panels are used in temperature-controlled clean rooms; aluminum honeycomb or handmade silica rock clean room panels can be selected for precision clean rooms; and ordinary machine-made rock wool sandwich panels can be used in storage aisles.