Friskluft

Friskluft is the Swedish term for fresh air, referring to outdoor air that dilutes indoor pollutants and helps maintain acceptable indoor environmental conditions. It is a central concept in ventilation and indoor air quality, distinguishing between the air outdoors and the air circulated inside buildings.

Adequate friskluft supplies oxygen, dilutes contaminants such as carbon dioxide, volatile organic compounds, moisture and odours, and supports thermal comfort. Proper ventilation is linked to reduced symptoms of sick building syndrome, headaches and fatigue, particularly in workplaces and educational settings. Conversely, insufficient friskluft or outdoor air that is heavily polluted can lead to respiratory irritation and mold growth.

Balancing friskluft involves trade-offs between air quality, energy use and outdoor conditions. Bringing in outdoor air can increase heating or cooling demands and may introduce pollutants in polluted zones. Many buildings use controlled ventilation to deliver sufficient friskluft while minimizing energy losses, often aided by recovery systems.

Technologies and approaches include natural ventilation, which relies on openings and pressure differences; mechanical ventilation with fans and ducts; and energy- or heat-recovery ventilation that exchanges heat or moisture between incoming and outgoing air. Filtration is used to remove particulates, and humidity control helps stabilize comfort. Modern systems increasingly employ sensors for CO2, VOCs and humidity to adjust ventilation in real time.

Standards and measurement: friskluft delivery is described by outdoor air ventilation rates, typically expressed in liters per second per person or by air changes per hour. Standards and guidelines exist worldwide, such as ASHRAE 62.1/62.2 in the United States and EN 16798 in Europe, tailored to climate, occupancy and building type.

See also: Indoor air quality; Ventilation; Energy efficiency.