A method and apparatus using deep pleated filters to provide efficient and
safe electrically enhanced filtering (EEF), with ultra low pressure drop,
higher efficiency of particulate removal and higher dirt holding capacity
over the life of the filter. An EEF may be constructed with a housing,
with or without an internal air moving device such as a fan, a deeply
pleated filter, preferably a V-pack filter with sets of downstream ground
electrodes and charge transfer electrodes borne by the exterior surface
of the filter packs that form the filtering element. An ionizer assembly
that ionizes the gas and charges particles entering the deeply pleated
filter and also transfers a charge to the charge transfer electrodes on
the filter pack. A plate seals the gasket on the filtering element
against the ionizing assembly. A high electrical potential is applied to
charging elements in the ionizer and, in some embodiments, a fan or motor
assembly. The charge transfer electrodes enable the device to function
with a high particle collection field between the charge transfer
electrodes and the downstream grounded electrodes to safely and
efficiently attain higher entrapment of the particles on the filter
medium.