Kokonaislämpöhäviö

Kokonaislämpöhäviö refers to the total amount of heat lost from a building or system to its surroundings. This concept is crucial in energy efficiency and building science, as minimizing heat loss directly translates to reduced energy consumption and lower heating costs. Heat can be lost through various mechanisms, including conduction, convection, and radiation.

Conduction is the transfer of heat through solid materials. In buildings, this occurs through walls, windows, roofs, and floors. Materials with poor thermal conductivity, such as insulation, are used to slow down this process. Convection involves heat transfer through the movement of fluids, like air or water. In a building, this can manifest as drafts or the circulation of warm air rising and cooler air falling. Sealing air leaks and improving ventilation strategies can mitigate convective heat loss. Radiation is the transfer of heat through electromagnetic waves. Warmer surfaces radiate heat to cooler surfaces. For instance, heat can radiate from a warm interior surface through a window to the colder exterior.

The overall heat loss from a building is typically calculated using methods like the U-value, which represents the rate of heat transfer through a specific building component, and the overall thermal transmittance of the building envelope. Factors influencing total heat loss include the building's size, insulation levels, window quality, air tightness, and climate conditions. Understanding and quantifying kokonaislämpöhäviö allows for targeted improvements to enhance thermal performance and energy sustainability.