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DDK DUCT (IN-SLAB DUCT SYSTEM)

General information - Components - Fan Sizing Table -Testing data

The DDK in-slab duct system is a rectangular spiral seamed duct set into the structural concrete floors of high-rise buildings. This duct system is used primarily to exhaust air from bathroom fans, range hoods and clothes dryers.

The DDK in-slab duct system meets the following specifications:

  • made with high quality galvanized steel using a spiral wound seam
  • 3 hour F and FT rating tested in accordance with ULC S115-M95 and ASTM E814-02 test requirements
  • impact load testing in accordance with CAN 3 A23.1 M77, Falsework for Construction Purposes
  • point load testing in accordance with CSA S269 A23.1 M77, Falsework for Construction purposes
  • airflow and duct friction charts provided in accordance with SMACNA and ASHRAE guide

The DDK in-slab duct system consists of regular and reinforced slab duct as well as a full range of fittings, as detailed on the following page.

COMPONENTS

The DDK in-slab duct system includes the following components:

DDK DUCT - 12" x 1-3/4"*

FAN SIZING TABLE

TESTING DATA

Fire Endurance Test:

The DDK duct system has a 3-HR F & FT Rating. The DDK slab duct system was tested in accordance with ULC S115-95 and ASTM E814-02.

Impact Load Test:

For the impact load test, 440 lbs. of gravel was dropped directly onto DDK slab duct from a height of 1.5 m. DDK slab duct passed the test with no measurable permanent deformation (tested to CAN3-A23).

Point Load Test:

For the point load test, a rigid plate was placed along the length of DDK slab duct. The plate was loaded with a force of 225 lbs. Once the load was removed, DDK slab duct exhibited no measurable permanent deformation (tested to CSA S269.1-1975).

Friction Test:

Various airflow measurements were taken on a typical section of DDK slab duct to determine the friction loss. Pressure loss measurements were also taken on various fittings to determine their friction loss and to calculate equivalent length of these fittings. The results of these tests were used to construct a fan sizing table to allow customers to match fan delivery to DDK slab duct systems at required airflow rate.

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