11 Floor, wall, ceiling and radiator heating, ventilation and cooling systems, district heating systems, snow and ice prevention systems, composed primarily of tubes, pipes, heat meters, valves, controllers and manifolds through which water circulates and structural parts therefor; dripper irrigation systems and sustainable onsite water recycling and wastewater treatment systems, composed primarily of pipes, tubes, sewer pipes, valves, filters and regulators; tap water supply and distribution systems in the nature of water purification installations, composed primarily of pipes, tubes, valves, filters and regulators; drainage systems in the nature of water conditioning units, composed primarily of pipes, tubes, sewer pipes, valves, filters and regulators; sewerage systems and sanitary piping in the nature of sewage purification installations composed primarily of tubes, pipes, valves, controllers and regulators; apparatus for heating and ventilating, namely, air-conditioning units, ceiling fans, electric fans, electric heating fans, electric fan heaters, fans for air-conditioning, ventilating fans for commercial and industrial use; structural and replacement parts for the aforementioned goods