IEC 60704-2-7:1997

Overview

IEC 60704-2-7:1997 specifies the test code for the determination of airborne acoustical noise emitted by household and similar electrical fans. It provides particular requirements for measuring noise emissions from fans including their accessories and component parts, all as a single unit, designed for use with either alternating current (a.c.) or direct current (d.c.) supply. This standard is intended for fans such as table fans, pedestal fans, ceiling fans, and partition (wall and window) fans used in residential or similar environments.

The aim is to support precise, reproducible measurement and comparison of noise emitted by these appliances, reflecting conditions of practical use, and thereby supporting manufacturers, testing laboratories, and regulatory authorities in product performance assessment and noise labelling.

Key Topics

• Scope: Applies to standalone electrical fans for household and similar applications, including various fan types (table, pedestal, ceiling, and partition). Does not apply to fans integral to other appliances, fans designated exclusively for industrial purposes, or fans with additional functions (e.g., heating, humidification).
• Measurement Conditions: Test conditions are designed to simulate practical use, ensuring consistent measurement results across laboratories. For example, fans are to be tested at their maximum speed under normal operational conditions, with adjustment for other speeds as needed.
• Noise Emission Measurement:
  • Focuses on airborne acoustical noise only.
  • Utilizes defined measurement surfaces (e.g., hemispherical arrays for partition and wall-mounted fans) and positions for microphones as specified in the standard.
  • Mandates the use of equipment such as windscreens and standardized test tables to enhance measurement accuracy.
• Test Room and Setup: Guidelines for test room design suggest maintaining free-field or semi-anechoic conditions, and specific placement and mounting instructions for various fan types-ensuring no unintended interference with airflow or sound measurement.
• Instrumentation and Reporting: Specifies proper instrumentation (including corrections for microphone sensitivity with windscreens) and the exact information to record and report, aligned with the general requirements of IEC 60704-1.

Applications

IEC 60704-2-7:1997 is widely used in several professional and regulatory contexts:

• Product Development and Quality Assurance: Manufacturers apply this standard during design and pre-market testing to ensure that household fans meet defined noise emission limits and performance expectations.
• Conformity Assessment and Certification: Testing laboratories use the methods specified to provide verifiable, repeatable noise emission data for certification and compliance with national or regional acoustical regulations.
• Product Labeling and Consumer Information: Data obtained using IEC 60704-2-7 may support accurate product labelling for noise levels, allowing consumers to make informed choices based on acoustical performance.
• Market Surveillance: Regulatory bodies reference the standard in market control procedures to ensure that products in circulation reflect tested and declared noise emissions.

Related Standards

For a comprehensive approach to airborne acoustical noise measurement of electrical appliances, consider the following related IEC standards:

• IEC 60704-1: General requirements for noise measurement test codes for household and similar electrical appliances. Part 2-7 is intended for use in conjunction with Part 1.
• IEC 60704-3: Procedures for determining and verifying declared noise emission values.
• IEC 60665: Specifications for a.c. electric ventilating fans and regulators for household and similar purposes.
• IEC 60879: Performance and construction requirements for electric circulating fans and their regulators.
• ISO 3743-1, ISO 3743-2, ISO 3744: Reference standards for acoustical measurement methods, addressing environments and setup requirements for sound emission testing.

By following IEC 60704-2-7, manufacturers, testing facilities, and regulatory agencies ensure a consistent, internationally recognized approach to fan acoustical noise testing, benefitting consumer confidence and harmonizing trade requirements.