11 AIR FILTERING UNITS, AIR PURIFICATION UNITS, WATER FILTERS, WATER PURIFICATION UNITS, WATER DISTILLATION UNITS, WASTE WATER RECOVERY AND PURIFICATION UNITS, WATER CONDITIONING UNITS, AND SYSTEMS INCORPORATING SUCH UNITS; PARTS AND SUBSYSTEMS FOR GREENHOUSES, NAMELY HEATERS, FANS, VENTILATORS, PLANT WATERING SYSTEMS, NAMELY IRRIGATION SPRINKLERS AND DRIP IRRIGATION SYSTEMS, AND HUMIDIFIERS