2006 New York Code - Exemptions From Permit Requirement.

 
    §  27-184 Exemptions from permit requirement. An equipment work permit
  shall not be required in any of the following cases:
    (a) Air-conditioning and ventilating systems. Where the  system  is  a
  voluntary system serving only one floor of a building and:
    (1)  Does not use lot line windows for the intake or exhaust of air or
  the mounting of equipment.
    (2) Is not installed in any public hallway, passageway, or stairway.
    (3) Does not in any way reduce the ventilation of any  room  or  space
  below that required by code provisions.
    (4) Does not penetrate any fire division, roof, floor, or wall (except
  that  a  packaged  air-conditioning  unit not exceeding three tons rated
  capacity may be used in windows or in sleeves  under  windows,  provided
  that health, fire and/or structural safety is not thereby impaired).
    (b)  Elevators,  etc.  Where  the  equipment  consists  of  a portable
  elevating device used  only  for  handling  materials  and  located  and
  operated entirely within one story.
    (c)  Fuel-burning  and fuel-oil storage equipment. Where the equipment
  consists of any of the following:
    (1) Portable fuel-burning equipment that does not require a chimney or
  vent connection.
    (2) Portable heaters used in construction work.
    (3) Oil-fired heaters having a fuel-storage capacity of six gallons or
  less (except that internal combustion engines of any size shall  require
  a permit).
    (d) Refrigerating systems. Where the system:
    1.  Has  a  capacity  of  twenty-five tons or less and uses a Group A1
  refrigerant.
    (2) Is to be installed in a vehicle, railroad car, or vessel.
    (3) Uses water or air as the refrigerant.
    (e) Hot water boilers and steam boilers operating at a gauge  pressure
  of  not  more  than  fifteen pounds per square inch located in dwellings
  occupied by less than six families.