UL 181
Standard for Factory-Made Air Ducts and Air Connectors

DETAILS
Edition Number:11SCC Approved:--
Edition Date:2013-07-25DOD Approved: 1994-07-20
Price Code:CANSI Approved: 2017-04-13
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements apply to materials for the fabrication of air duct and air connector systems for use in accordance with the International Mechanical Code (IMC), International Residential Code (IRC), and Uniform Mechanical Code (UMC), Standards of the National Fire Protection Association for the Installation of Air-Conditioning and Ventilating Systems, NFPA No. 90A, and the Installation of Warm Air Heating and Air-Conditioning Systems, NFPA No. 90B.

    1.2 The air ducts and air connectors covered by these requirements include preformed lengths of flexible or rigid ducts, materials in the form of boards for field fabrication of lengths of rigid ducts, and preformed flexible air connectors.

    1.3 For the purpose of these requirements, air ducts and air connectors are classified as follows:

    Class 0 – Air ducts and air connectors having surface burning characteristics of zero.

    Class 1 – Air ducts and air connectors having a flame-spread index of not over 25 without evidence of continued progressive combustion and a smoke-developed index of not over 50.

  • TABLE OF CONTENTS
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    • Cover
    • Transmittal
    • Table of Contents
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 Components
          • 3 Units of Measurement
          • 4 Undated References
        • CONSTRUCTION
          • 5 Materials
        • PERFORMANCE
          • 6 General
          • 7 Tests for Surface Burning Characteristics
          • 8 Flame Resistance Test
          • 9 Bending Test
          • 10 Flame Penetration Test
            • 10.1 General
            • 10.2 Test equipment
            • 10.3 Sample preparation
            • 10.4 Pre-heat and stabilization
            • 10.5 Test method
          • 11 Burning Test
          • 12 Corrosion Resistance
            • 12.1 Test for zinc-coated steel
            • 12.2 Tests for coated steel (other than zinc-coated steel)
          • 13 Mold Growth and Humidity Test
          • 14 Temperature Test
            • 14.1 General
            • 14.2 Low temperature
            • 14.3 High temperature
          • 15 Puncture Test
          • 16 Static Load Test
            • 16.1 General
            • 16.2 Tests for rigid air ducts
            • 16.3 Tests for flexible air ducts and air connectors.
          • 17 Impact test
          • 18 Erosion Test
            • 18.1 General
            • 18.2 Test installation
            • 18.3 Test method
          • 19 Pressure Test
          • 20 Collapse Test
          • 21 Tension Test
          • 22 Torsion Test
          • 23 Leakage Test
        • MARKING
          • 24 Content
        • INSTRUCTIONS
          • 25 Installation Instructions