Electrostatic filters

Illustrated Guide to Ventilation (BG 2/2009), compiled by Kevin Pennycook and published by BSRIA in 2009, states: ‘Electrostatic filters or electronic air cleaners can be highly efficient in filtering out particulate contaminants like smoke, dust and pollen. There are three basic types: ionisation plate, charged media non-ionising, and the charged media-ionising type. The most common type of electrostatic precipitator is the ionising type. Thin wires suspended in the air stream are charged with a high positive voltage. The positive ions created in the ionising field become attached to particles which then pass into the collecting plate section. This section consists of a series of parallel plates, with alternative plates positively charged and the other plates at ground potential. The electric field forces the charged particles on to the oppositely charged plates. The retention of particles on the collector plates is by a combination of electrical and intermolecular adhesion. To improve the overall efficiency, a filter is often placed downstream of the collector plates to capture large agglomerated particles shed from the plates.’

--BSRIA

[edit] Related articles on Designing Buildings

• Air conditioning.
• Air filtration.
• Air quality.
• BSRIA articles.
• BSRIA definitions.
• Building services.
• HEPA filters.
• Indoor air quality.
• Mechanical ventilation.
• Natural ventilation.
• Primary filter.
• Secondary filter.
• Types of air filter.
• Ventilation.