How long do the filters last? A How long do the filters last? Permalink Always refer to the manufacturer’s specifications. But a general rule of thumb is:If used during smoke season, 3 months.If during regular usage, 6 month.Additional details on MERV 13-A filters which for sure will are the ones that last that long. Did you find this FAQ helpful? 1 0 Share facebook twitter linkedin pinterest email Back to Top previousHow expensive is the Corsi/Rosenthal Box?nextDo we need to wear masks even though we have a couple of air cleaners?