1. (1) Central heating furnaces in buildings containing places of public assembly shall be located elsewhere than in an area where persons are congregated. Each such furnace shall be supported by a floor having an incombustible surface and shall be so insulated or located as not to overheat adjacent woodwork or other combustible material. No combustible material shall be stored within five feet of such furnace. Chimneys and the connections between furnaces and chimneys shall be smoke and gas tight, firmly constructed and so located or insulated as not to overheat any adjacent combustible material. Ashes shall be kept in incombustible receptacles.
2. (2) In theatres and motion picture theatres of any capacity, or in other places of public assembly having over 600 capacity, hereafter constructed, the central heating furnace shall be enclosed by construction having a fire-resistance rating of at least two hours. The doors to such enclosures shall be self-closing fire doors having a fire-resistance rating of at least one hour. The finished floors and trim within such enclosure shall be of incombustible material.
3. (3) In places of public assembly other than theatres and motion picture theatres and having a capacity of 600 or less, hereafter constructed, the central heating furnace shall be enclosed by construction having a fire-resistance rating of at least one hour with self-closing fire doors of at least one hour fire-resistance rating.
4. (4) All openings which penetrate the enclosures of heating apparatus, such as warm air or ventilation ducts, shall be provided with incombustible self-closing dampers equipped with heat-actuated releasing devices of an approved type.
5. (5) No coil, radiator or pipe shall be placed so as to encroach upon the required width of any aisles, passageways or other means of exit.

6. (6) In places of public assembly hereafter constructed, no floor register shall be placed in aisles, passageways or other means of exit.

   (b) Direct fired space heaters.

7. (1) No direct fired space heating unit shall be located in the auditorium of any theatre or within seven feet of the floor of any other area where persons are congregated.

8. (2) Suspended types of direct fired heating units may be used without individual enclosures under the following conditions:

   1. (i) All portions of ceilings less than five feet above the unit for a radius of five feet around a point directly above it shall be of at least fire-resisting construction, or protected by a shield of incombustible material.
   2. (ii) Partitions less than 18 inches from the unit shall be similarly protected.
   3. (iii) Such protective shield shall be mounted with a one-inch space between it and the ceiling or partition.

   4. (iv) If such a unit is mounted closer than six inches to a ceiling, a shield of incombustible material shall be interposed between the heating unit and the ceiling.

      (c) Ventilation.

9. (1) Every place of public assembly having an occupancy of 200 or more persons, wherein a central system of air conditioning or mechanical ventilation is operated, shall be provided with an emergency switch conveniently located and conspicuously labeled for shutting down the fan in case of fire.

10. (2) Every refrigerating system employing a fluid which is vaporized and liquified in its refrigerating cycle shall comply with the American Standards Safety Code for Mechanical Refrigeration current at the time of its installation. Exception:

    Exception:

    Hermetically sealed unit systems containing not more than 10 pounds of refrigerant.

(a) Central heating.