Which type of insulation is generally characterized by high R-values?

Foam insulation is often noted for its high R-values, which measure the thermal resistance of insulation materials. The R-value indicates how well a material resists heat flow, with higher values signifying better insulation properties. Foam insulation, particularly rigid foam boards and spray foam, contains trapped air or gas bubbles that significantly reduce thermal conductivity. This structure enables foam insulation to provide superior insulation performance, making it particularly effective for minimizing heat loss in buildings.

Additionally, foam insulation can be used in various applications, including walls, roofs, and below-grade situations, enhancing its versatility. The ability to create an air seal, which further reduces heat transfer, adds to its effectiveness in energy efficiency. This makes it the preferred choice for applications requiring higher thermal performance, which often aligns with current energy efficiency standards.

In contrast, while other insulation types like fiberglass, cellulose, and rock wool also have insulating properties, they generally offer lower R-values compared to foam and may contribute to energy loss through air movement or lesser thermal performance under certain conditions.