Over the past 50 years, Zitrón has expanded to become one of the largest and most technologically driven and innovative venti ... lation companies in the world, spending much of its revenue on R&D, new equipment, personnel development and new manufacturing techniques. The company was established in 1963 to service the Spanish coal mining industry and has its Global Head Office and main factory located in Asturias, in the north of Spain. Currently, ZITRÓN global reach spans over 80 countries on 5 continents. read more