Certain manufacturers would have us believe that their vacuum cleaners are fitted with a ‘lifetime’ filter. But this is not true, unless they think that their product is to only last a few years. The purpose of a filter is to FILTER which, by definition, means that it must retain the particles that it was designed to filter. Whether it be an oil filter, an air filter or any other mechanical filter sooner or later it will become full with the particles it was designed to retain and need to be replaced.
Most vacuum cleaner ‘lifetime’ filters are little more than a crude sponge with a screen mesh. It is true that they can be washed through a few times but eventually they become so impregnated with dirt that washing will not thoroughly remove the retained particles.
In fact ‘vacuum’ cleaners are misnamed. Vacuum cleaners should actually be called ‘air flow’ cleaners. Nothing moves in a vacuum and vacuum cleaners rely on strong air flow to both pick up dirt and keep their motor cool. The cleaner the filters the greater the airflow which directly leads to increased dirt pick up and increased motor live.