Heatinsulating

Heat-insulating materials are used to limit heat transfer between spaces at different temperatures. They support energy efficiency, comfort, and safety by reducing heating and cooling loads in buildings, appliances, and industrial systems. Insulation slows heat flow by reducing conduction, limiting convection, and reflecting or diffusing radiant heat.

Conduction is impeded by low-thermal-conductivity materials; convection is suppressed by trapped air or gas within the insulation's structure; and radiation is reduced with reflective surfaces or aerogel. Many high-performance systems combine these mechanisms to achieve greater thermal resistance.

Common insulations include fiberglass and mineral wool fibers; foam plastics such as polystyrene and polyisocyanurate; natural options like cork and cellulose; and advanced materials such as aerogel and vacuum-insulated panels. Insulation is available as batts, blankets, boards, sprays, or loose-fill, and as cavity fill or radiant barriers.

Performance is described by thermal conductivity (k) and, with thickness, by R-values or RSI. Typical k values range from about 0.013 W/mK (aerogel) to 0.04–0.05 W/mK (fiberglass, cellulose); foams are around 0.025–0.030 W/mK. Higher R-values per unit thickness indicate better insulation; U-values measure heat transfer per area and time, lower is better.

Applications include building envelopes, roofs, walls, and floors; pipes and tanks; and appliances and industrial systems. Installation emphasizes air sealing and moisture control, proper vapor retarders, and compatibility with framing. Environmental considerations cover embodied energy, recyclability, and selection of blowing agents and fire protection.