Source: US2012199003A Disclosed is an air distribution control unit or a filtration/ventilation unit which is portable and/or can be mounted on or integrated in furniture e.g. as a cabinet of at the head region of a bed. The filtration/ventilation unit cleanses air from a person/patient by aspirating the person's/patient's exhalation air into the filtration/ventilation unit. To construct an at least partly isolated area around the patient, filtered air can be directed e.g. vertically out of the filtration/ventilation unit to perform an air curtain. Use of the filtration/ventilation unit reduces the risk of dissipation of air-borne diseases and health hazardous matter, and reduces the amount of air to ventilate a room with patients.