Abstract: The invention concerns a method to select the smoke treating unit (3) of a system (1) of a roasting apparatus (2) and an associated smoke treating unit when said system is used in a room (10), said method comprising:—receiving room data input,—receiving roasting use data input in order to determine the quantity of each contaminant produced by the roasting apparatus during a period,—for each system of the roasting apparatus and of one smoke treating units, calculating the concentration of each contaminant present in the room during said period,—for each system and for each contaminant, comparing the calculated concentration of said contaminant present in the room during the period with the concentration of said contaminant authorised according to local health and safety regulations,—selecting the smoke treating unit of the system in the list of smoke treating units providing for each contaminant a calculated concentration inferior to the authorised concentration.

Abstract: The invention concerns a system for roasting coffee beans comprising: —a roasting apparatus (1), said apparatus producing smoke, and—a smoke treating unit (2) configured to collect and treat smoke produced by the roasting apparatus, wherein: —the roasting apparatus comprises a smoke outlet (11), and—the smoke treating unit comprises: a smoke inlet (21) configured to cooperate with the smoke outlet of the roasting apparatus, a smoke filtering sub-unit (22) comprising at least an active carbon filter (221), a smoke driver (23) configured to circulate smoke through the smoke treating unit from the smoke collecting device to an outlet (25) of the smoke treating unit, wherein the smoke treating unit (2) comprises an air inlet (24) configured to mix the smoke produced by the roasting apparatus (1) with ambient air before the smoke is circulated through the smoke filtering sub-unit (22).