An exhauster is a device that creates suction to remove air, fumes, or gases from an enclosed area. It extracts stale or polluted air to ensure adequate ventilation. Exhausters are typically found in industrial settings, kitchens, and general ventilation systems. In contrast, a blower forces air into a space under pressure, not by suction. A washer purifies air using water or chemicals but does not remove it via suction. A drier eliminates moisture from air or materials, functioning independently of air removal fans. Therefore, a fan operating via suction is identified as an exhauster.