Eristävyysarvo

Eristävyysarvo, often translated as insulation value or thermal resistance, is a measure used to quantify how effectively a material or structure resists the flow of heat. It is a critical concept in building science, energy efficiency, and the design of thermal insulation.

The higher the eristävyysarvo, the better the material is at preventing heat transfer. This means that a material with a high eristävyysarvo will keep a building warmer in winter and cooler in summer, reducing the need for artificial heating and cooling and consequently lowering energy consumption.

In practical terms, eristävyysarvo is often expressed using the R-value. The R-value is directly proportional to the thickness of the insulating material and inversely proportional to its thermal conductivity. Different materials have different inherent thermal conductivities, and by increasing the thickness of a material, its eristävyysarvo can be increased.

For building components like walls, roofs, and floors, the overall eristävyysarvo is a cumulative effect of all the layers present. This includes the insulation material itself, as well as other components like plasterboard, cladding, and air gaps. Understanding and calculating the total eristävyysarvo is essential for meeting building regulations and achieving desired energy performance targets. Various standardized testing methods are used to determine the eristävyysarvo of materials and building assemblies.