soojuskadusid

Soojuskadusid, or heat losses, are the amount of heat energy that escapes from a building to the outside due to a temperature difference between interior and exterior environments. They depend on building fabric performance, ventilation practices, and air leakage, as well as thermal bridging at junctions.

The main components of heat loss are conduction through walls, roofs, and floors; radiation and conduction through windows and doors; ventilation heat loss from air exchange; infiltration and exfiltration; and thermal bridges at structural connections.

Measurement and calculation are used to assess soojuskadusid in buildings. Engineers estimate losses using the surface area and the thermal transmittance (U-value) of each element. A common relation is Qdot = U * A * ΔT for individual parts, with the total heat loss rate equal to the sum of these contributions. The overall difficulty is often summarized by a heat loss coefficient (in watts per kelvin, W/K). Building energy performance certificates use these values to rate efficiency.

Mitigation strategies aim to reduce soojuskadusid by improving the building envelope and systems. Actions include increasing insulation, upgrading windows and doors, sealing leaks, minimizing thermal bridges, and implementing controlled ventilation with heat recovery to retain inside warmth while supplying fresh air.

Context and significance: In northern climates, such as Estonia, reducing heat losses is central to energy efficiency, lowering heating costs, and reducing emissions. Policy measures, building codes, and energy performance standards guide improvements and investments in the building stock.