Ventilator

A ventilator comprising:

• an air blower;
• a casing comprising
• a first wall and a second wall configured to house the air blower centrally and to define a radially decreasing volume therebetween,
• a circumferential gap between the first wall and the second wall configured to allow a high velocity air stream to exit and to spiral in a direction away from a structure to which the ventilator is configured to be mounted, and
• a central opening in the second wall configured as a suction inlet of the air blower;
• and
• a flow amplifier adjacent the casing, the flow amplifier comprising a flow amplifying wall provided in parallel with the second wall of the casing and is configured to amplify air flow through an air flow passage defined between the flow amplifying wall and the second wall of the casing.