A method of monitoring the service life of a filter (1) in a filter system
equipped with a fan, in particular a filter (1) in an air conditioning system
of a motor vehicle, the instantaneous air speed (21) preferably being measured
on each startup of the system using a sensor (2, 20) downstream from the
filter (1), compared to the reference air speed (R) from the unloaded filter
(1), and transmitted to a service computer and/or indicated on a display,
and the need to replace the filter being signaled when this value falls below a
predetermined threshold or threshold range of the instantaneous air flow rate (21).
