A chimney cowl serves as the termination point for gravity ventilation ducts as well as exhaust ducts. It is equipped with a rotor set on ball bearings working in oil, guaranteeing long-lasting, trouble-free, and quiet operation. It assists in improving chimney draft. The cowl harnesses the wind and its energy to create a partial vacuum in the ventilation duct. The pressure difference between the chimney duct and atmospheric pressure causes air to be drawn out of the building. A chimney cowl protects the ventilation duct from atmospheric precipitation and disruptions in draft. Thanks to chimney cowls, ventilation systems will function properly under all conditions. The cowl is designed so that the cowl dome automatically aligns itself in the direction that ensures proper ventilation, regardless of the wind’s direction. The chimney cowl is resistant to high temperatures and aggressive working environments.