Understanding Thermal Conductivity

Thermal conductivity is a crucial parameter when selecting appropriate insulation for specific applications. It represents a material’s ability to conduct heat through itself, indicating how thermal energy moves from one area to another within the material through conduction. In other words, thermal conductivity helps evaluate a material’s efficiency in heat transfer. Insulation with low thermal conductivity can prevent heat loss or gain better than those with high thermal conductivity, making it suitable for applications requiring maximum temperature reduction.

Important facts about thermal conductivity:

• Materials with low thermal conductivity transfer heat slowly or with difficulty, making them ideal for thermal insulation. Lower values indicate better temperature reduction capability.
• Materials with high thermal conductivity transfer heat quickly, such as metals, making them suitable for applications requiring heat transfer.
• Thermal conductivity is measured in watts per meter per kelvin (W/m·K). Lower values indicate better insulating properties (the lower, the better).
• Knowing the thickness and thermal conductivity of chosen insulation allows calculation of temperature reduction after installation (Before vs After Temperature).
• Examples of thermal conductivity values in heat-resistant insulation materials:
• Fiberglass: 0.041 – 0.125 W/m·K
• Ceramic Fiber: 0.06 – 0.17 W/m·K
• Mineral Wool: 0.05 – 0.18 W/m·K
• Aerogel: 0.013 – 0.066 W/m·K (very low)

Note: According to ASTM C335 standard, the maximum recommended thermal conductivity for thermal insulation should not exceed 0.065 W/m·K at 200°C and 0.073 W/m·K at 450°C.