Säteilylämpövuoto

Säteilylämpövuoto refers to the heat transfer that occurs through electromagnetic radiation. Unlike conduction, which requires direct contact, or convection, which relies on fluid movement, radiation can transfer heat across a vacuum. All objects with a temperature above absolute zero emit thermal radiation. The amount and type of radiation emitted depend on the object's temperature and its emissivity.

In building physics, säteilylämpövuoto is a significant factor in energy loss, especially in poorly insulated structures or during periods of high temperature differences. Heat radiated from a warmer surface travels in all directions and can be absorbed by cooler surfaces, contributing to the overall heat flow. This phenomenon is particularly relevant in windows, where glass can both emit and absorb radiant heat. Low-emissivity coatings on windows are designed to reduce this form of heat transfer by reflecting infrared radiation back into the building.

Understanding säteilylämpövuoto is crucial for designing energy-efficient buildings and for optimizing thermal comfort. In winter, it contributes to heat loss from the interior to the colder exterior. Conversely, in summer, it can lead to heat gain from the sun or surrounding hot surfaces into the building. The concept is also applied in various industrial processes and in understanding the thermal balance of the Earth's atmosphere.