Abstract: An air purifying system for a vacuum cleaner. An airflow reduction chamber is insertable along an airflow passage of the vacuum cleaner so that air pumped by the vacuum cleaner passes in the airflow reduction chamber prior to being released out in the open. The airflow chamber has an air inlet and an air outlet and an inner wall extending therebetween. An air deflector plate is positioned in front of one of the air inlet and the air outlet inside the airflow reduction chamber. A UV lamp of a type emitting radiations killing germs and bacteria extends inside the airflow reduction chamber. At least a portion of the inner wall of the air chamber at a level of the UV lamp has a surface reflective to UV radiations emitted by the UV lamp. A control circuit controls operation of the UV lamp.