loftskiptum

Loftskiptum is an Icelandic term used in building and ventilation engineering to describe the deliberate exchange of indoor air with outdoor air. The primary purpose is to dilute indoor pollutants, control humidity, and maintain thermal comfort for occupants. Loftskiptum can be achieved through natural ventilation, where openings such as windows and vents allow air to move driven by wind or buoyancy, or through mechanical ventilation, including exhaust, supply, or balanced systems. Modern buildings often employ mechanical ventilation with heat recovery (ERV) or heat recovery ventilation (HRV) to minimize energy loss while preserving air quality.

Ventilation rates are typically expressed as air changes per hour (ACH) or as volumetric flow rates per person (liters per second per person) or per area (liters per second per square meter). The required loftskiptum depends on factors such as building type, occupancy, activities, and climate. In cold climates like Iceland, standards commonly emphasize adequate ventilation to prevent condensation and maintain indoor air quality, while using energy recovery to reduce heating needs.

Design considerations for loftskiptum include the airtightness of the building envelope, filtration quality, humidity control, and strategies for achieving comfort without creating drafts or excessive noise. Challenges can include drafts in natural ventilation, noise from mechanical systems, and the risk of over-ventilation during milder seasons. Building codes and energy efficiency guidelines typically set minimum ventilation rates and quality requirements to balance air quality with energy use.

Historically, the concept of exchanging indoor air with outdoor air arose from concerns about indoor pollutants and later adapted to emphasize energy efficiency. See also: HVAC, Indoor air quality, Heat recovery ventilation, Energy efficiency.