Comment by highwaylights

Almost all of these review sites, not understanding the physics involved, believe a HEPA filter sieves particles down to a size of 0.3 microns, which implies that anything smaller passes on through.

This is utterly false. HEPA filters are measured at the efficiency of what’s known as the MPP (the Most Penetrating Particle size). It’s the hardest particle size to capture as it can get by the two methods used to capture large particles (impaction), and smaller particles (diffusion).

Considering almost none of the air in a room is passing through the filter at a given moment, the efficiency of the filter is less important than how much air it moves through the filter media per minute, which IKEA have favoured here.

Essentially this filter performs close to par with more expensive units, while using less energy, and having dramatically lower costs for filter replacements when due.

What they don’t do is give reviewers either kickbacks or basic physics lessons.