Air cleaner technologies

There are three main types of air cleaner: electrostatic, media and charged media. Each has its own benefits and issues.

Electrostatic systems pass an electrical charge across the air flowing into the unit. This causes them to stick to a differently charged surface, taking them out of the air. These units tend to be very effective but, partly as a result, they require frequent filter changes as they soon become full of particles. This causes them to ‘arc’ and make ‘cracking’ noises. The filters require careful handling as the tolerances are very precise.

Media systems pass the air flowing into the machine over a material - often a sort of filter paper – onto which the particles stick. These units are often not as effective as electrostatic units but they tend to require less frequent filter changes. There are no annoying noises when they stop working – they just stop removing the contamination from the air. The filters are usually disposable.

Charged media systems try to combine the two techniques. They do not always do this very efficiently, which may be why the other two types are more common. When new they are highly effective but their effectiveness can drop very fast.