Do you mean a 3 meter by 4 meter room? A room that is only 3 feet by 4 feet seems like it would be a little small...even if it was a bathroom or a closet.

The unit should list CFM, CADR, or both. This is the best way to approximate how appropriate the unit is for a specific room. If it does not list this, then I would strongly advise not purchasing it. I would also want to know more details on the filter itself. For example, what kind of a filter is it, what is the filter change interval, and how expensive are replacement filters?

Finally, with the absolute minimal details listed on the box, I would assume that this system (like most of the consumer units) is going to cover particulate filtration only (i.e., particulate matter, or PM). It will not reduce volatile organic compounds (VOCs) or nitrogen oxides, which would require a chemical filtration component that only specialized purifiers have. And as it does not remove VOCs, it will not make a meaningful impact on odors other than moving the air around (large carbon filters are needed to actually remove odors through the process of adsorption, which are available with specialty purifiers.)

If the room is 12 feet by 16 feet, that is about 200 square feet. You would be very amply covered by something like a Winix 5500-2, which would provide a high level of air exchanges even on a lower (quieter) fan setting. The 5500-2 can be purchased for as little as $150 and replacement filters are reasonably priced. Energy usage and noise is also very reasonable. Like most of the consumer filters, it covers particulate filtration but does not make meaningful impacts on VOCs or NOx.