Luftfilters

Luftfilters are devices that remove contaminants from air. They are widely used in heating, ventilation and air conditioning systems, automotive cabins, clean rooms and various industrial processes to improve indoor air quality and protect equipment.

Filters work by trapping particles in a porous media. Common types include mechanical filters such as fiberglass or pleated media, high-efficiency filters known as HEPA (high efficiency particulate air) that achieve at least 99.97% efficiency for 0.3 µm particles, ULPA (ultra-low penetration air) filters with even higher efficiencies, activated carbon filters to reduce gases and odors, and electrostatic or hybrid filters that use electrical charges to capture particles. Selection depends on the target contaminants, required efficiency and pressure drop within the system.

Performance and standards are described by several metrics. Efficiency ratings include MERV (minimum efficiency reporting value) on a broad scale, with higher numbers indicating greater filtration efficiency; HEPA and ULPA grades provide standardized performance. In consumer products, CADR (clean air delivery rate) measures output. Testing and classification standards include ISO 29463 and EN 1822 for HEPA/ULPA, ASHRAE 52.2 for testing particulate filtration, and various national or regional standards such as AHAM CADR.

Maintenance and replacement are essential for reliable performance. Filters should be replaced or cleaned according to manufacturer guidelines or when a noticeable decrease in airflow occurs. Improper installation or a damaged seal can allow bypass flow, reducing effectiveness. Environmental considerations include disposal and, for some filters, potential recycling.

Choosing a Luftfilter involves considering contaminants, required efficiency, airflow, space constraints and energy use, as well as maintenance practicality and lifecycle costs.