The Powerfoil X3.0 from Big Ass Fans uses a hermetically sealed gearbox that never requires maintenance. In addition to manual control, the included SmartSense controller can automate fan operation year-round for optimal energy efficiency. The substantial airflow provided quickly eliminates odors and fumes from treatment facilities; additionally, this airflow augments the fume-removal capabilities of existing ventilation fans and louvers. Its airflow also helps keep workers up to 10 degrees F cooler during the hottest summer months, making facilities without air conditioning more comfortable and safer. It is available in diameters from 8 to 24 feet. 877-244-3267; www.bigassfans.com