Wärmedurchlasswerte

Wärmedurchlasswerte, often translated as thermal transmittance or U-values, represent the rate of heat transfer through a building element or material. This value quantifies how effectively a material or a composite structure resists the passage of heat. A lower Wärmedurchlasswert indicates better insulation, meaning less heat will escape from a warm interior to a colder exterior or vice versa. Conversely, a high Wärmedurchlasswert signifies poor insulation, allowing for significant heat loss.

The Wärmedurchlasswert is typically expressed in units of Watts per square meter Kelvin (W/m²K). This unit signifies the amount of heat energy in Watts that flows through one square meter of the building element when there is a temperature difference of one Kelvin (or Celsius) between the two sides. For example, a wall with a Wärmedurchlasswert of 0.5 W/m²K will lose half as much heat as a wall with a Wärmedurchlasswert of 1.0 W/m²K under the same temperature conditions.

In building construction, Wärmedurchlasswerte are crucial for assessing the energy efficiency of windows, doors, walls, roofs, and floors. Regulations and building codes often specify maximum permissible Wärmedurchlasswerte for different building components to ensure adequate thermal performance and minimize energy consumption for heating and cooling. Calculating the overall Wärmedurchlasswert of a composite structure involves considering the thermal resistance of each individual layer and their arrangement.