What are Pre-insulated Duct Board Materials?

In the Heating, Ventilation, and Air Conditioning (HVAC) system, air ducting plays a crucial role. Recent innovations and various factors have necessitated the revolution of air ducting. The Pre-insulated system is a proven, easy-to-use, and innovative product, virtually eliminating all the issues associated with traditional metal ductwork. The key features of pre-insulated duct board are as follows:

Low Thermal Conductivity: With thermal conductivity as low as 0.024W/mK, these ducts significantly reduce electricity costs.
Flame Retardant Properties: Suitable for many HVAC air systems due to their excellent flame retardant properties.
Cost-Effective Installation: Installation costs are 10% lower than those of traditional sheet metal ducts.
Lightweight: Pre-insulated ducts are lightweight and easy to handle, requiring fewer people for installation.
Durability: The duct board is strong, capable of withstanding a pressure of 0.25Mpa and a bending force of 2Mpa.

Types of Pre-Insulated Duct Board Materials

Phenolic Duct:

Phenolic duct panels are made of phenolic insulation foam with aluminum foil or galvanized iron sheets on both sides. These panels are widely used in HVAC systems due to their energy-saving, environment-friendly, and fireproof properties. They have the best thermal properties. For internal use, 80mm embossed phenolic panels are recommended, while for external use, 200mm aluminum foil or GI sheet surfaces are preferred for better bending and compressive strength.

The thermal conductivity of phenolic foam ranges from 0.025W/(mK) to 0.35W/(mK), outperforming rubber, plastic, and glass wool materials. This excellent thermal insulation prevents air duct condensation. Additionally, the unique connection method of phenolic composite air ducts ensures superior air tightness, nearly eight times that of galvanized steel ducts. This results in significantly lower heat dissipation loss compared to other ducts:

Galvanized steel duct: 15%
Fiberglass duct: 8%
Phenolic duct: less than 2%

PU Duct:

PU ducts consist of polyurethane (PU) insulation foam with aluminum foil or galvanized iron sheets on both sides. The outer layer is made of high-purity thin aluminum, and the middle layer is flame-retardant rigid polyurethane foam. PU pre-insulated duct board boast high strength, B1-level flame retardancy, waterproof and moisture-proof properties, pollution-free materials, and stable performance.

PIR Duct:

PIR Pre-insulated Duct Panels are made of polyisocyanurate (PIR) insulation foam, typically with aluminum foil or galvanized iron sheets on both sides. PIR is a rigid foam insulation material formed by the reaction of isocyanate with polyether and a catalyst. It offers excellent flame retardant properties, low thermal conductivity, and good dimensional stability. PIR is suitable for thermal insulation of industrial pipes and equipment ranging from -196°C to +120°C, as well as for heating and ventilation pipes, building walls, and ship insulation.

Compared to phenolic ducts, PIR ducts provide environmental benefits, stable physical properties, good strength, no dust, no peeling, no slag, and long service life. Compared to PU ducts, PIR ducts offer better fire resistance. During ablation, a dense carbonized layer forms on the surface, hindering the continuous burning of foam plastic and producing minimal smoke and irritation. In contrast, burning polyurethane produces dripping, releases large amounts of irritating gas, and generates significant smoke.

Summary

In summary, the evolution of air ducting in HVAC systems, driven by innovations such as pre-insulated duct board, has significantly improved efficiency, safety, and cost-effectiveness. Pre-insulated ducts, including phenolic, PU, and PIR options, offer superior thermal conductivity, flame retardant properties, and ease of installation compared to traditional metal ducts. These advancements not only reduce energy costs but also enhance the overall performance and durability of HVAC systems. As a result, pre-insulated ducting represents a forward-thinking solution that meets the growing demands for energy efficiency and environmental sustainability in modern building practices.