BS EN ISO 5136-2009 PDF

Full title and description

STB BS EN ISO 5136-2009 — Acoustics. Determination of sound power radiated into a duct by fans and other air‑moving devices. In‑duct method. This standard specifies the in‑duct test method for measuring the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of a fan or similar air‑moving device; it is the EN/BS adoption of ISO 5136 (edition 2).

Abstract

ISO/EN/BS ISO 5136 defines test arrangements, instrumentation, measurement procedures and calculation methods for determining one‑third‑octave band and overall sound power levels radiated into ducts by ducted fans and other air‑moving equipment. The method is suitable for steady, broad‑band, narrow‑band and discrete‑frequency sounds and includes guidance on uncertainty, signal‑to‑noise requirements, and annexes covering small and large duct adaptations.

General information

• Status: Published as BS EN ISO 5136:2009 (adoption of EN ISO 5136:2009 / ISO 5136:2003); maintained/confirmed by the issuing bodies and subject to periodic review.
• Publication date: EN/BS designation year 2009 (EN publication reported 8 May 2009); BSI listing/adoption published/issued for sale in 2010 (BS publication listing dated 30 April 2010).
• Publisher: British Standards Institution (for the BS version, published as BS EN ISO 5136:2009); original international document published by ISO as ISO 5136:2003.
• ICS / categories: Acoustics and fan/ventilator equipment — ICS codes shown include 17.140.20 (noise emitted by machines and equipment) and 23.120 (ventilators, fans, air‑conditioners).
• Edition / version: BS EN ISO 5136:2009 (corresponding to ISO 5136:2003, 2nd edition).
• Number of pages: Typically published as ~80 pages in the BS/EN release (page counts reported vary by publisher/format; BSI/retail listings commonly show 80 pages).

Scope

The standard applies to ducted fans and other air‑moving devices where sound is radiated into a duct; it is used to determine sound power radiated into an anechoically terminated duct on inlet and/or outlet sides. Test duct diameter range addressed by the method is nominally 0.15 m to 2 m (with informative provisions for smaller and larger ducts in annexes). The procedure covers required test environment, instrumentation, microphone and sampling‑tube arrangements, flow straightening and swirl limits, uncertainty estimation and signal‑to‑noise criteria; it is not intended for non‑ducted fans.

Key topics and requirements

• Test arrangement and duct specifications for anechoic termination and duct mounting.
• Instrumentation and system calibration (microphones, sampling tubes, shielding against turbulent pressure fluctuations).
• Measurement positions, sampling‑tube mounting and rules for microphone placement and shields (foam ball, nose cone, sampling tube — with suggested maximum mean flow velocities per shield type).
• Procedures for conducting measurements with/without outlet flow straighteners and treatment of swirl.
• Signal‑to‑noise requirements (minimum S/N relative to turbulent pressure fluctuations) and uncertainty analysis leading to designated accuracy grade.
• Annexes with computational procedures, corrections for modal effects and provisions for very small and very large ducts.

Typical use and users

Used by acoustic test laboratories, fan and HVAC equipment manufacturers, design engineers, product compliance teams and certification bodies to quantify in‑duct sound power for product data sheets, noise‑control design and regulatory or contractual noise requirements. Results support product comparison, specification of silencers/attenuators and verification of declared sound emission data.

Related standards

Commonly used alongside other acoustics and fan standards such as ISO 5801 (fan performance / airflow testing), ISO 3744 / ISO 3746 (other sound power determination methods), and ISO 12001 (accuracy/grade definitions). These documents are frequently cross‑referenced when planning combined performance and noise tests.

Keywords

Acoustics, fan noise, in‑duct method, sound power, ducted fans, sampling tube, microphone shielding, flow straightener, sound power level, uncertainty, ISO 5136, BS EN ISO 5136.

FAQ

Q: What is this standard?

A: It is the in‑duct acoustics test method (BS EN ISO 5136:2009) for determining sound power radiated into a duct by fans and other air‑moving devices; it is the EN/BS adoption of ISO 5136:2003.

Q: What does it cover?

A: Test facility requirements, duct and sampling arrangements, instrumentation and calibration, measurement procedures, calculation methods for one‑third‑octave and overall sound power, uncertainty analysis, and informative annexes for small/large ducts and corrections.

Q: Who typically uses it?

A: Acoustic test laboratories, HVAC and fan manufacturers, R&D engineers, certification bodies and consultants performing in‑duct noise measurements or producing declared sound power data.

Q: Is it current or superseded?

A: The ISO technical base (ISO 5136:2003) remains the identified international edition for this method and EN/BS adoption was published as BS EN ISO 5136:2009; national/EN catalogues show the 2009/2010 adoption as the current EN/BS edition but the document is subject to periodic review by the issuing bodies (check the issuing body for the latest status before using).

Q: Is it part of a series?

A: It sits within a family of acoustics standards addressing sound power measurement (e.g., ISO 3744 / 3746 survey and precision methods) and is used together with fan performance standards such as ISO 5801 when tests couple airflow and acoustic measurements.

Q: What are the key keywords?

A: Acoustics, fan noise, in‑duct, sound power, ducted fans, microphone sampling tube, flow straightener, sound power level, measurement uncertainty.