VDI 3731 Blatt-2 1990-11 PDF

Full title and description

VDI 3731 Blatt 2 — Emissionskennwerte technischer Schallquellen; Ventilatoren (Characteristic noise emission values of technical sound sources; fans). Technical guideline specifying how to describe, report and classify the noise-emission characteristics of fans for use in product data sheets, comparison, procurement and acoustic planning.

Abstract

This Blatt 2 of VDI 3731 (published November 1, 1990) provides definitions, measurement conditions, accuracy classes and recommended presentation formats for characteristic noise-emission values of fans. It summarises available emission data, gives rules for reporting noise in spectral and octave-band form, defines standard deviations/accuracy classes, and describes a standardized noise-emission label and forms (including annexes on noise reduction measures and a data-recording (ETS) sheet). The guideline is intended to make fan noise data comparable across manufacturers and test reports.

General information

• Status: Published; listed as current by official VDI listings and standards distributors.
• Publication date: 1 November 1990 (1990-11).
• Publisher: Verlag des Vereins Deutscher Ingenieure (VDI).
• ICS / categories: 17.140.20 (Noise emitted by machines and equipment); 23.120 (Ventilators / fans).
• Edition / version: VDI 3731 Blatt 2 (Blatt‑2), edition November 1990.
• Number of pages: 22.

Scope

Applies to the specification, measurement reporting and labelling of acoustic emission characteristics for axial, centrifugal and other technical fans. It defines the characteristic noise quantities, measurement conditions and presentation formats to be used when providing emission values so that test results and product data are directly comparable. It does not replace detailed type‑test methods but gives a harmonised way to present and classify results for practical use in selection, procurement and system design.

Key topics and requirements

• Definitions of characteristic noise quantities and required spectral/octave-band data.
• Specified measurement conditions and environmental/test set‑up requirements for reporting emission values.
• Accuracy classes and associated standard deviations for reported values.
• Compilation and presentation of emission values specific to fans (tables and example data).
• Standardised format for noise‑emission labelling of fans to support comparison.
• Guidance on the origin and verification of emission data (manufacturer data, test reports, literature).
• Annexes covering practical noise‑reduction measures for fans and a standardized ETS data‑collection sheet.
• Terminology, symbols and formulae used in acoustic reporting.

Typical use and users

Used by fan manufacturers for preparing product data sheets and noise labels; by acoustic and HVAC engineers when selecting fans or predicting system noise; by test laboratories when reporting emission data; and by procurement/specification authors who require comparable noise data for tenders and project documentation.

Related standards

Related or referenced documents commonly associated with this guideline include other parts of VDI 3731 (e.g., Blatt 1 for compressors), VDI guidelines on fan testing and air-handling systems (for example VDI 2044, VDI 2081 Blatt 1 and VDI 2087), and building/acoustic standards used for verification and insulation data (e.g., relevant parts of DIN 4109). The guideline is intended to be used alongside formal test methods and ISO standards for acoustic measurement where applicable.

Keywords

fan noise, noise emission, emission values, sound sources, VDI 3731, measurement conditions, accuracy classes, noise labelling, HVAC acoustics, spectral data, octave bands

FAQ

Q: What is this standard?

A: VDI 3731 Blatt 2 is a VDI guideline (Blatt‑2) that defines characteristic noise‑emission values and the recommended way to report and label fan noise for comparability and practical use.

Q: What does it cover?

A: It covers definitions of acoustic quantities, measurement and reporting conditions, accuracy classes and standard deviations, presentation formats for emission values specific to fans, and includes annex guidance on noise reduction and a standard data sheet.

Q: Who typically uses it?

A: Fan manufacturers, test laboratories, acoustic and HVAC engineers, specification writers and procurement teams who need consistent, comparable fan noise data.

Q: Is it current or superseded?

A: The document was published on 1 November 1990. It is still listed in major standards catalogues as the published Blatt 2 edition; however users should verify whether newer national or international test methods or more recent VDI/DIN documents have since introduced updated measurement or reporting requirements before relying on it as the sole reference.

Q: Is it part of a series?

A: Yes — VDI 3731 is a series of guidelines covering characteristic noise emission values of technical sound sources; Blatt 1 covers compressors and Blatt 2 covers fans. Other related VDI documents address measurement methods, system acoustics and related topics.

Q: What are the key keywords?

A: Fan noise, noise emission values, emission labelling, spectral data, octave bands, measurement conditions, accuracy classes, VDI 3731.