37 Installation, maintenance, and repair of air humidifying apparatus, air humidifying apparatus for poultry houses, greenhouses, perishables storage, cigar humidors, and public spaces, air-filtration apparatus, air-filtration apparatus for commercial and industrial spaces, sanitizing apparatus, sanitizing apparatus for disinfecting air and objects in commercial and industrial spaces, sanitizing apparatus for disinfecting vehicles, environmental control systems, namely, fog sprayers for disinfectants and chemicals, water-treatment equipment, water-filtration equipment, reverse-osmosis equipment for removing minerals from water, anti-scalant equipment for neutralizing minerals in water, and misting apparatus for aeroponic growing systems