ilmansiirtoon

Ilmansiirto, in English often translated as air transfer or air exchange, refers to the movement of air into, out of, or within enclosed spaces. In Finnish technical usage the illative form ilmansiirtoon is used to describe the process or operation of transferring air, and appears in building codes, HVAC documentation, and environmental assessments.

The movement of air is driven by pressure differences created by wind, indoor-outdoor temperature differences (the stack effect), and by mechanical ventilation systems. Natural infiltration and exfiltration occur through leaks and openings in walls, floors, and ceilings. When mechanical systems are used, air is distributed through ducts to control ventilation, thermal comfort, and indoor air quality, while balancing heat recovery and energy use.

Measurement and modeling are central to understanding ilmansiirto. A common metric is the air exchange rate (air changes per hour, ACH). Tracer gas techniques and CO2 decay methods quantify air transfer in real buildings. Modeling approaches include zone models for whole-building behavior and computational fluid dynamics (CFD) for detailed flow patterns and mixing in spaces.

Applications of ilmansiirto knowledge include designing energy-efficient buildings, controlling humidity and contaminants, and improving occupant comfort. It also supports assessments of pollutant and odor transport, wildfire smoke infiltration, and the impact of ventilation on indoor air quality. Proper management of ilmansiirto aims to ensure sufficient fresh air while minimizing unwanted heat loss and energy consumption.

See also: ventilation, infiltration, HVAC, indoor air quality, air exchange rate.