23 33 00 AIR DUCT ACCESSORIES

.01 Fire Dampers

1. Fire dampers shall be installed where required by the International Mechanical Code and NFPA.
2. Temperature rating of fusible links shall be shown in the contract documents.
3. Frames shall be large enough so that there will be no obstruction to air flow when the dampers are open.  Construction and arrangement of fire dampers shall be as approved in each case prior to installation.  Access shall be provided for replacement of links and so labeled.
4. Fire dampers shall be approved by U.L. and so labeled and installed, shall comply with the requirements of NFPA 90A and the International Mechanical Code. 

.02 Sound Attenuators

1. Refer to 23 05 01.04 Sound Pressure Level Requirements. 
2. An analysis is required for both supply and return ductwork systems.
3. Drawings shall indicate velocity, S.P. loss, and db attenuation through all octave bands for each attenuator.