How do electrostatic air cleaners remove particles such as dust and cigarette smoke?

Electrostatic air cleaners, or electrostatic precipitators, remove particles like dust and smoke by applying an electric charge to the contaminants as they pass through the unit.12

The process functions through the following steps:

• Charging: As air flows into the device, it passes between discharge electrode wires that carry a high-voltage direct current. This creates an electric field that imparts an electric charge to the suspended particles.12
• Collection: The charged particles are then attracted to oppositely charged collection plates—typically grounded metal plates—where they become trapped.12
• Removal: Once a layer of particles accumulates on the plates, they are removed periodically. In industrial settings, this is often done via mechanical "rapping" or vibration, causing the debris to fall into a collection hopper. For consumer-grade home units, the plate arrays are often removable for manual cleaning with specialized solutions.12

While highly effective at capturing fine particulate matter, these devices require regular maintenance to clean the collection plates and should be monitored, as some models can produce ozone as a byproduct.2