Ilmanpidätys

Ilmanpidätys, often translated as airtightness or air-tightness, refers to the degree to which a building's envelope prevents uncontrolled air leakage. This leakage can occur through cracks, gaps, and openings in the building's construction, such as around windows, doors, and penetrations for pipes and wires. A well-sealed building significantly reduces the amount of air that passes into or out of the structure unintentionally.

The concept of ilmanpidätys is crucial in modern building science and construction. It is closely related to energy efficiency, as uncontrolled air leakage can lead to substantial heat loss in winter and heat gain in summer. This loss and gain directly impact the energy required for heating and cooling, thus increasing energy consumption and operational costs. Furthermore, poor ilmanpidätys can contribute to moisture problems within the building structure, potentially leading to mold growth, material degradation, and reduced indoor air quality.

Measuring and achieving adequate ilmanpidätys is a standard practice in many countries. Methods like blower door testing are used to quantify the airtightness of a building. This test involves depressurizing or pressurizing the building and measuring the amount of air that needs to be supplied to maintain that pressure. Building codes and energy efficiency standards often specify maximum allowable air leakage rates. Improving ilmanpidätys typically involves careful design, selection of appropriate materials, and meticulous construction techniques, including the use of air barriers and sealants.