2006 New York Code - Charging Chutes And Exhaust Flues.

 
    §  27-840 Charging chutes and exhaust flues. All incinerators shall be
  constructed with a flue within a chimney  to  exhaust  the  products  of
  combustion  and a refuse charging chute which shall be separate from the
  flue.  Refuse  charging  chutes  shall  not  discharge   directly   into
  incinerators,  except  in  buildings classified in residential occupancy
  group J and in accordance with the requirements of this  subchapter  and
  subchapter fifteen of this chapter.
    Flues for existing incinerators and existing refuse chutes may be used
  as refuse charging chutes provided they are in good condition and comply
  with the requirements of subchapter fifteen of this chapter.