How often should this exhaust filter be replaced?
For residential machines, every few years; for commercial use, every 6 months to a year.
Which vacuums use this filter?
SEBO Felix and Dart vacuums.
Why does the replacement interval differ between residential and commercial use?
Commercial machines run more frequently and under heavier use, so the filter needs changing more often, every 6 months to a year, versus every few years for residential machines.