18-28-1104.3.4 Protection from refrigerant decomposition.
   Where any device having an open flame or surface temperature greater than 800°F (426°C) is used in an independent circuit, a hood and exhaust system shall be provided in accordance with Article 5, Exhaust Systems. Such exhaust system shall discharge combustion products to the outdoors.
   Exception: A hood and exhaust system shall not be required.
      1.   Where the refrigerant is R-717, R-718m R-744;
      2.   Where the combustion air is ducted from the outdoors in a manner that prevents leaked refrigerant from being combusted.