Kokonaislämpövastus

Kokonaislämpövastus, often abbreviated as Rsi or Rse depending on context, represents the combined thermal resistance of building elements. It is a crucial concept in building physics and energy efficiency calculations. Thermal resistance quantifies how well a material or a combination of materials prevents heat transfer. Higher thermal resistance indicates better insulation.

In building science, kokonaislämpövastus is typically used to describe the thermal performance of building components such as walls, roofs, and floors. It takes into account the resistance of all the layers within the component, including any air layers. For instance, when evaluating a wall, the kokonaislämpövastus would be the sum of the thermal resistances of the plaster, insulation, brickwork, and any other materials forming the wall structure.

The unit of thermal resistance is typically square meters Kelvin per Watt (m²·K/W). This unit reflects the temperature difference (in Kelvin) across a unit area (in square meters) that results in a heat flow of one Watt.

The concept of kokonaislämpövastus is essential for determining energy consumption for heating and cooling buildings. A higher kokonaislämpövastus for the building envelope leads to lower heat loss in winter and reduced heat gain in summer, thus improving energy efficiency and occupant comfort. Building codes and energy performance standards often specify minimum requirements for the kokonaislämpövastus of different building elements.