What is the difference between ‘Active’ & ‘Passive’ Air Purification?

There are two types of air purifiers available for home use, which use two main kinds of purification processes. These are:

• Passive type air purifiers, which are the standard HEPA filters, where the air is drawn into the machine and passed through a filter to remove contaminants, before clean air is released on the other side.

• Active type air purifiers, that send cleaning agents out into the space to clean the air, and create an ambient atmosphere.