How often should air filters be cleaned or replaced?

Filter maintenance intervals are application specific and depend on the type of equipment they are used in and the environmental conditions the equipment is subjected to. Some equipment design engineers add messages to the controlling software of their device displays to indicate when filters should be serviced based on hours of operation. Others include pressure and / or temperature sensors downstream of the filter to detect when the filter is fully loaded and needs attention. It is accepted throughout the industry for electronics equipment designers to recommend cleaning or replacing air filters approximately every 90 days.