Cabin air filtration system for agricultural machines

Cab air treatment apparatus for an agricultural machine, comprising an external air inlet (10), a filtration system (20), an air conditioning system (30), and a cab air supply outlet (40). The filtration system comprises, in order: a first filter (21), a second filter (23), upstream of which is arranged a bypass valve (22) for selectively putting the adsorption filter (23), or a bypass branch (24) arranged in parallel with the second filter (23), in communication with the system (20), a blower (25) for providing a desired pressurization downstream of the cab air supply outlet (40), and a deflecting valve (26) having a main outlet (26a) connected to the air conditioning system (30), and a discharge outlet (26b) for cleaning the filtration system (20), said outlets being operable alternatively to one another.