IEC 60704-2-7:2020 pdf download – Household and similar electrical appliances – Test code for the determination of airborne acoustical noise – Part 2-7: Particular requirements for fans.
6.4 Loading and operating of appliances during tests 6.4.1 Replacement: Load and operation should simulate normal use. Fans that can be tilted during normal use shall be located in the position with the highest emitted noise level, and the duration of the measurement shall be at least 10 s. Fans that can oscillate automatically shall operate when oscillating. In the case of oscillating appliances, the A-weighted sound pressure level shall be averaged on at least one complete cycle. 6.4.3 Not applicable. 6.5 Location and mounting of appliances 6.5.1 Addition: Ceiling fans may be hung from a special support instead of from the ceiling. In this case, care shall be taken to ensure that the means of suspension or clamping do not change the sound output of the appliance. In order not to restrict the airflow, the distance between the lowest edge of the appliance and the reflecting plane (usually the floor) shall be at least 1,5 m. Alternatively, ceiling fans can be mounted in the reverse working position on the reflecting plane, providing this does not affect sound radiation. 6.5.2 Not applicable. 6.5.3 Not applicable. 6.5.4 Replacement: Partition (wall and window) fans shall be mounted in an opening made either: – in a wall of the special reverberation test room; or – on the second reflecting plane of the free field over a reflecting plane environment. The height between the centre of the appliance and the floor shall be 1,5 m ± 0,05 m. In all cases, care shall be taken to follow the instructions given by the manufacturer and to avoid any structure-borne noise. Care shall be taken to avoid any restriction of the airflow. Attention shall be paid to avoid any difference of pressure between the rooms concerned (or atmosphere), in order to avoid an unwanted load on the fan.
6.5.5 Not applicable. 6.5.7 Not applicable. 7 Measurement of sound pressure levels This clause of Part 1 is applicable except as follows: 7.1 Microphone array, measurement surface and RSS location for essentially free- field conditions over reflecting plane(s) 7.1.1 Addition: This measurement surface shall be used for table, pedestal, louver, tower, bladeless, ceiling bracket and ceiling fans. Table fans are placed on the floor. This measurement surface shall not be used for wall bracket fans and window fans. The use of a windscreen is mandatory. 7.1.2 Not applicable. 7.1.3 Not applicable. 7.1.4 Replacement: For partition (wall and window) fans and wall-mounted table fans, the measurement surface is a hemisphere, with 10 microphone positions as specified in Figure 101, centred in the projection of the geometrical centre of the reference box on the vertical plane, the coordinate system describing the microphone positions being located with the x- and y-axes in the vertical reflecting plan and the z-axis horizontally perpendicular to it. The x-axis lies in the horizontal central plane of the reference box. The front of the fan is directed towards the z- axis. The area of this measurement surface is S = 2πR 2 . The radius of the hemisphere is 1 m. 7.1.5 Not applicable. 7.1.6 Addition:This measurement surface shall be used for tall pedestal fans. 7.2 Microphone array and RSS location in hard-walled test rooms Not applicable. 7.4 Measurements 7.4.4 Not applicable. 8 Calculation of sound pressure and sound power levels This clause of Part 1 is applicable. 9 Information to be recorded This clause of Part 1 is applicable except as follows: 9.7 Electric supply, water supply, etc. 9.7.3 Not applicable. 9.7.4 Not applicable. 10 Information to be reported This clause of Part 1 is applicable, except as follows: 10.3 Test conditions for the appliance 10.3.4 Not applicable. 10.3.5 Not applicable.