Suggested Division 15 Specifications Square, Rectangular or Round Neck Ceiling Diffusers - High Capacity Model: TDC-NT - Fixed Discharge Ceiling diffusers shall be TITUS Model TDC-NT (steel) for a fixed, horizontal discharge pattern. Diffuser shall be compatible with 24 x 24-inch modules for regressed narrow tee ceiling systems. These diffusers shall consist of an outer frame assembly of the sizes and mounting types shown on the plans and outlet schedule. A square or rectangular inlet shall be an integral part of the frame assembly and a transition piece shall be available to facilitate attachment of round duct. An inner core assembly consisting of fixed deflection louvers shall be available in one-, two-, three- or four-way horizontal discharge patterns. The inner core assembly must be removable in the field without tools for easy installation, cleaning or damper adjustment. The finish shall be #26 white. The finish shall be an anodic acrylic paint, baked at 315°F for 30 minutes. The pencil hardness must be HB to H. The paint must pass a 100-hour ASTM B117 Corrosive Environments Salt Spray Test without creepage, blistering or deterioration of film. The paint must pass a 250-hour ASTM D870 Water Immersion Test. The paint must also pass the ASTM D2794 Reverse Impact Cracking Test with a 50-inch pound force applied. Optional damper shall be constructed of heavy gauge steel. Damper must be operable from the face of the diffuser by removing the spring loaded inner core assembly. Optional Throw Reducing Vanes (TRV) must be available to deflect a horizontal discharge airstream from each side of the TDC diffuser into diverging airstreams. The manufacturer shall provide published performance data for the diffuser. The diffuser shall be tested in accordance with ANSI/ASHRAE Standard 70-1991.