18-28-514.2 Prohibited applications.

   Energy recovery ventilation systems shall not be used in the following systems:

   1.    Hazardous exhaust systems covered in Section 18-28-510.

   2.   Dust, stock and refuse systems that convey explosive or flammable vapors, fumes or dust.

   3.   Smoke control systems covered in Section 18-28-513.

   4.   Commercial kitchen exhaust systems serving Type I hoods.

   5.   Clothes dryer exhaust systems covered in Section 18-28-504.

   Exception: The application of ERV equipment that recovers sensible heat only utilizing coil-type heat exchangers shall not be limited by this section.

(Added Coun. J. 9-14-21, p. 35949, Art. V, § 27)

18-28-514.3 Access.

   A means of access shall be provided to the heat exchanger and other components of the system as required for service, maintenance, repair or replacement.

(Added Coun. J. 9-14-21, p. 35949, Art. V, § 27)

18-28-514.4 Recirculated air.

   Air conveyed within energy recovery ventilation systems shall not be considered as recirculated air where the energy recovery ventilation system is constructed to limit cross-leakage between air streams to less than 10 percent of the total airflow design capacity.

(Added Coun. J. 9-14-21, p. 35949, Art. V, § 27)

Article VI. Duct Systems (18-28-601 et seq.)

18-28-601 General.

18-28-601.1 Scope.

   Duct systems used to move air in air-conditioning, heating, ventilating and exhaust systems shall conform to the provisions of this chapter except as otherwise specified in Articles V, Exhaust Systems and Article 7, Combustion Air.

   Exception: Ducts discharging combustible material directly into any combustion chamber shall be constructed of not less than 12 U.S. gauge steel casing and shall be lined with not less than 4 1/2 in. (114 mm) of firebrick (ASTM C27) Type F, medium duty, or the equivalent. The charging hopper shall not exceed 6 ft. (1.8 m) in length, measured from the floor opening to the outside of the roof of the incinerator combustion chamber.

   The charging opening shall be protected by a cover extending beyond the edges of the opening for at least 2 in. (51 mm) on all sides and lined with at least 2 1/2 in. (63.5 mm) of refractory material.

   The charging floor opening shall be located in a room with walls and floor and ceiling assemblies having a fire resistance rating of at least 2 hours, with openings protected by approved self-closing or automatic-closing 3-hour fire doors suitable for Class A openings. Such doors shall be kept closed during the charging operation and at other times, except when waste material is delivered to the room.