Ilmankierron

Ilmankierron is a Finnish term that translates as "air circulation" and commonly denotes the movement and exchange of air in indoor spaces or systems. The concept covers both natural processes, driven by temperature and pressure differences, and mechanical systems that control airflow for ventilation, thermal comfort and pollutant removal.

In buildings, effective ilmankierron is critical for indoor air quality (IAQ), occupant health and energy performance. Proper circulation reduces concentrations of carbon dioxide, volatile organic compounds, moisture and airborne pathogens, and helps maintain even temperatures. Poor air circulation can lead to discomfort, odors, mold growth and elevated health risks.

Types of ilmankierron include natural ventilation (windows, vents, stack and wind effects), mechanical ventilation (supply, exhaust and balanced systems), displacement ventilation and mixed-flow systems. System design considers factors such as airflow rates, air changes per hour (ACH), filtration, humidity control and heat recovery. Heat recovery ventilators and energy-recovery systems are often used to lower energy costs while providing fresh air.

Assessment and regulation of ilmankierron rely on measurements like airflow rates, ACH and indoor CO2 levels, and follow guidance in building codes and standards for ventilation and occupational health. Routine maintenance—filter replacement, duct cleaning and system balancing—is essential to sustain performance.

In sum, ilmankierron is a central element of building design and operation, affecting comfort, health and energy use; its appropriate planning and maintenance help ensure safe and efficient indoor environments.