18-28-1107.5 Joints and refrigerant-containing parts in air ducts.
   All connections located within a ventilation system shall be formed by fusion welding or socket type brazed fittings. No valves, devices or connections thereto shall be located in a ventilation system, except systems containing less than 100 pounds (45.36 kg) of refrigerant and do not contain a warm air furnace or electric resistance heating coil.