Section 27-343. Ducts, pipes and conduits through rated construction

(a)
  Installation of ducts which pass through construction required to have a
  fire-resistance rating shall comply with the requirements of  subchapter
  thirteen,  provided  that,  notwithstanding the provisions of subchapter
  thirteen or reference standard RS 13-1, noncombustible ducts which  pass
  through  construction  required  to have a fire-resistance rating of one
  hour must be provided with fire dampers unless:
    (1) The building is classified in occupancy group C, E, or H-2; and
    (2) Complete  sprinkler  protection  is  provided  for  the  floor  in
  accordance with subchapter seventeen; or
    (3)  The openings for the ventilation ducts do not exceed three square
  feet in area; or
    (4) The duct is protected  on  both  sides  of  the  partition  for  a
  distance  equal  to the maximum duct dimension by a sleeve affording one
  hour fire separation for such horizontal distance.
    (b)  Noncombustible  pipes  and  conduits.  Noncombustible  pipes  and
  conduits   may   pass   through   construction   required   to   have  a
  fire-resistance rating provided that  the  space  between  the  pipe  or
  conduit  and  its sleeve or opening does not exceed one-half inch and is
  completely  packed  with  mineral  wool  or  equivalent   noncombustible
  material  and  is  closed off by close-fitting metal escutcheons on both
  sides of the construction; and provided further that the  aggregate  net
  area  of  such openings does not exceed twenty-five square inches in any
  one hundred square feet of wall or floor area (excluding  the  areas  of
  openings  for  sleeves  which  are  firestopped in conformance with this
  section and section 27-345).
    (c) Openings for passage of pipe and ducts whose  aggregate  net  area
  exceeds twenty-five square inches in any one hundred square feet of wall
  or  floor  area  (excluding opening for sleeves which are firestopped in
  conformance  with  this  section  and   section   27-345)   may   pierce
  constructions  required  to  have a fire-resistance rating only when the
  type of construction to be used has  been  tested  with  such  types  of
  facilities  installed in place and the proportionate area of openings of
  such facilities to be installed in the construction does not exceed  the
  proportionate  area  of openings in the assembly tested, and provided no
  opening is larger than that in the assembly tested. Protection  of  such
  openings shall be the same as provided in the test. All openings through
  hollow  fire  rated construction shall be sleeved with sheet metal least
  No. 14 U.S. std. gage thick.
    (d) The installation and proper functioning of required  fire  dampers
  shall  be  subject  to the controlled inspection requirements of section
  27-132 of this code, except that it  shall  not  be  required  that  the
  architect or engineer be in the employ of the owner.