EN 1505:1997

• Abstract:

  This European Standard specifies dimensions of sheet metal air ducts and duct fittings with rectangular cross section. It applies to ductwork used in ventilation and air conditioning systems in buildings subject to human occupancy. The wall thickness of ducts and fittings is not specified in this standard; strength and leakage are dealt with in prEN 1507. The corresponding standard for circular ducts is prEN 1506.

• Status: Published
• Publication Date: 16-Dec-1997
• Withdrawal Date: 29-Jun-1998
• ICS: 91.140.30 - Ventilation and air-conditioning systems
• Technical Committee: CEN/TC 156 - Ventilation for buildings
• Drafting Committee: CEN/TC 156/WG 3 - Ductwork
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 16-May-2024
• Completion Date: 09-Sep-2026
• Directive: Harmonized Standard305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive:

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  Not Harmonized89/106/EEC - Construction products
• Ref Project: SIST EN 1505:1999 - Ventilation for buildings - Sheet metal air ducts and fittings with rectangular cross section - Dimensions

• Refers: EN 12792:2003 - Ventilation for buildings - Symbols, terminology and graphical symbols
• Effective Date: 28-Jan-2026
• Refers: EN 1506:2007 - Ventilation for buildings - Sheet metal air ducts and fittings with circular cross-section - Dimensions
• Effective Date: 28-Jan-2026
• Referred By: EN 12101-6:2005 - Smoke and heat control systems - Part 6: Specification for pressure differential systems - Kits
• Effective Date: 28-Jan-2026
• Referred By: EN 12236:2002 - Ventilation for buildings - Ductwork hangers and supports - Requirements for strength
• Effective Date: 28-Jan-2026
• Referred By: EN 15423:2008 - Ventilation for buildings - Fire precautions for air distribution systems in buildings
• Effective Date: 28-Jan-2026
• Referred By: EN 15727:2010 - Ventilation for buildings - Ducts and ductwork components, leakage classification and testing
• Effective Date: 28-Jan-2026
• Revised: prEN 18289 - Ventilation for buildings - Metallic ventilation ducts - Requirements and test methods
• Effective Date: 03-Dec-2025

Overview

EN 1505:1997 - "Ventilation for buildings - Sheet metal air ducts and fittings with rectangular cross section - Dimensions" is a European Standard published by CEN that defines the dimensional series for rectangular sheet metal air ducts and associated fittings used in building ventilation and air-conditioning systems. It applies specifically to ductwork serving buildings subject to human occupancy. The standard sets out how rectangular ducts and fittings are sized and coordinated; it does not specify wall thickness, strength or leakage performance.

Key topics and requirements

• Scope: Dimensions for sheet metal air ducts and fittings with rectangular cross sections used in ventilation and air-conditioning systems for occupied buildings.
• Dimensional coordination: Series of standard widths and heights intended to ensure compatibility and interchangeability between ducts and fittings from different manufacturers.
• Exclusions: Wall thickness, mechanical strength and leakage performance are not covered by EN 1505; those aspects are addressed in related documents (see Related Standards).
• Application boundaries: Standard applies to sheet metal construction; other materials or circular ducts are covered by separate standards.

Practical applications

EN 1505 is used wherever consistent, compatible sizing of rectangular ductwork is required:

• HVAC designers and building services engineers: Select standard duct sizes to simplify system layout and ensure component compatibility.
• Duct manufacturers and fabricators: Produce sheet metal ducts and fittings to a harmonized dimensional series for interchangeability and reduced fabrication complexity.
• Installers and contractors: Streamline installation with pre-dimensioned components that fit standard fittings and connectors.
• Specifiers and procurement teams: Reference EN 1505 in tender documents and specifications to require standard dimensions and simplify supply chains.
• Quality control and inspection: Verify that supplied rectangular ducts conform to recognized European dimensions.

Benefits include improved modularity, easier coordination between suppliers, reduced waste, and clearer procurement/specification language for ventilation systems.

Related standards

• prEN 1507 - addresses strength and leakage requirements for rectangular ductwork (wall thickness and performance).
• prEN 1506 - the corresponding standard for circular sheet metal ducts.
• National adoptions: EN 1505:1997 has been adopted by member bodies (for example, SIST EN 1505:1999).

Keywords: EN 1505, ventilation for buildings, sheet metal air ducts, rectangular duct dimensions, ductwork standards, HVAC standards, ventilation and air-conditioning.