A non-transitory computer readable medium comprising a computer program, wherein the computer program comprises instructions which, when executed by a computer, a processor, or a control unit, cause the computer, the processor, or the control unit to perform a method to select a smoke treating unit of a system, wherein the system comprises (i) at least one pre-defined coffee beans roasting apparatus and (ii) the smoke treating unit, wherein the smoke treating unit is selected from the group consisting of afterburners, catalytic afterburners, filters able to retain volatile organic compounds, hydrocarbons and/or particulate matters, electrostatic precipitators, a duct connected to the outside of the room, and combinations thereof, the method comprising the steps of:
- receiving room data input indicating a country of of a room in which the system is used and providing directly or indirectly a ventilation rate of the room,
- receiving roasting use data input indicating an intended use of the at least one pre-defined coffee beans roasting apparatus during a pre-determined period, wherein the roasting use data input comprises a quantity of coffee beans roasted per the pre-determined period and times of a roasting operation during the pre-determined period,
- determining a quantity of each contaminant produced by the at least one pre-defined coffee beans roasting apparatus during the pre-determined period, wherein determining the quantity comprises the steps of:
- getting access to a quantity of each contaminant produced by the at least one pre-defined coffee beans roasting apparatus during one roasting operation of a specific quantity of a specific type of coffee beans up to a specific roasting level,
- based on the roasting use data input and on the quantities during the one roasting operation,
- determining the quantity of each contaminant produced by the at least one pre-defined coffee beans roasting apparatus during the pre-determined period,
- a concentration of each contaminant present in the room during the pre-determined period for each smoke treating unit, by:
- getting access, for each smoke treating unit, to an amount of reduction of each contaminant by the smoke treating unit,
- determining a quantity of each contaminant dispensed by the system during the pre-determined period for each smoke treating unit by subtracting (i) the determined quantity of each contaminant produced by the at least one pre-defined coffee beans roasting apparatus during the pre-determined period by (ii) the amount of reduction of each contaminant by each smoke treating unit,
- calculating, from the ventilation rate and from the quantity of each contaminant dispensed by the system during the pre-determined period, the concentration of each contaminant present in the room during the pre-determined period,
- for each smoke treating unit and for each contaminant, comparing the concentration of the contaminant present in the room during the pre-determined period with an authorized concentration of the contaminant according to local health and safety regulations,
- selecting at least one smoke treating unit where the concentration of each contaminant present in the room during the pre-determined period is inferior to the authorized concentration.