We present an implementation using two Pasat air heaters to heat the surfaces of two halls of a plant producing steel structures and dealing with the galvanizing of steel elements. These halls are exposed to significant cooling due to the poor insulation of the structure. Thanks to heaters, a constant temperature is maintained in the facility, which allows for ensuring appropriate working conditions and storage of materials, tools and machines. Despite the difficult conditions in which they operate, the heaters have been operating flawlessly and without failure for many seasons.