Where the demands on the indoor climate are higher than usual
There are different procedures to measure the quality and cleanliness of the air. ISO 14644 is a standard used to measure air cleanliness. According to this standard, particles and their size are measured per cubic metre of air.
In a cleanroom the air is kept particle-free by using an air filter in the ventilation system, usually a HEPA filter. A HEPA filter ensures that the air supplied to the room is clean and free of contamination and at the same time creates the prerequisites to be able to control and satisfy the set cleanliness requirements.
HEPA filters are available in 5 different filtration classes where the designation refers to the filtration capacity, i.e. how many particles that the filter can capture per litre of air. HEPA 14 lets through max 5 particles per litre air, which corresponds to 99.99% of all particles. This makes the filter suitable for ventilation systems in cleanrooms.