ISO/TC 117/WG 13 - Jet fans

This document specifies determining sound power levels of fans under standardized laboratory conditions from sound pressure levels measured in a reverberant room. This document is applicable for determination of the acoustic performance of fans. This document can additionally be applied to determine the acoustic performance of fans combined with an ancillary device, such as a roof cowl or damper or, where the fan is fitted with a silencer, the sound power resulting from the fan and silencer combination. For guidance of testing with ancillary items, see Annex C. This document applies to fans as defined in ISO 13349-1. It is limited to the determination of airborne sound emission for the specified set-ups. Vibration is not measured, nor is the sensitivity of airborne sound emission to vibration effects determined. This document is intended to be used in conjunction with ISO 5136, which covers the in-duct method, and ISO 10302-1 for small fans. The size of fans which can be tested in accordance with this document is limited only by the practical aspects of the test set-up. Test fan dimensions and air performance will control the room size. NOTE Based on usage, small fans can be tested according to this document or to ISO 10302-1. For reverberant field tests, the size of equipment under test is limited to less than 2 % of the room volume. For low power fans (up to 3 kW) that can be run from a domestic power supply (single phase AC at a voltage not exceeding 250 V and a current not exceeding 16 A), reference IEC 60704-2-7[18]. The test arrangements in this document establish the laboratory conditions necessary for a successful test. It is difficult to meet these requirements in situ and this document is not intended for field measurements. In these situations, users are reminded that the acoustic environment is unlikely to meet the specified conditions and there can be additional acoustic system effects where inlet and outlet conditions at the fan are less than ideal.

This document establishes principles for the determination of the acoustic performance of fans. In addition, this document can be used to determine the acoustic performance of fans combined with an ancillary device such as a roof cowl or damper or, where the fan is fitted with a silencer, the sound power resulting from the fan and silencer combination.

This document specifies a method to measure sound power by using sound intensity measurements on a measurement surface which encloses the sound source. This document provides guidelines on the acoustical environment, ambient noise, measurement surface, and number of measurements. The installation categories are generally designed to represent the physical orientation of a fan installed in accordance with ISO 5801, ISO 13350 and also defined in ISO 13349-1. This document is applicable to fans defined in ISO 5801 and ISO 13349-1. This document is limited to the determination of airborne sound emission for the specified installation categories. Vibration is not measured, nor is the sensitivity of airborne sound emission to vibration effects determined. The sizes of the fan, which can be tested in accordance with this document are limited only by the practical aspects of the test installations.

ISO 13347-3:2004 applies to industrial fans as defined in ISO 5801 and ISO 13349. It is limited to the determination of airborne sound emission for the specified set-ups. Vibration is not measured, nor is the sensitivity of airborne sound emission to vibration effects determined. The sizes of fan which can be tested in accordance with ISO 13347-3:2004 are limited only by the practical aspects of the test set-up. Dimensional limitations, test fan dimensions, and air performance will control the room size, power and mounting requirements for the test fan. The test arrangements in ISO 13347-3:2004 establish the laboratory conditions necessary for a successful test. Rarely will it be possible to meet these requirements in situ and ISO 13347-3:2004 is not intended for field measurements. Intending users are reminded that, in these situations, there may well be additional acoustic system effects where inlet and outlet conditions at the fan are less than ideal. The enveloping surface methods may be used for the determination of open inlet and/or open outlet sound power level of fans for standardized installation types. An estimation (with increased uncertainty) of ducted sound power for fans too small, or otherwise inconvenient, for testing by the in-duct method described in ISO 5136 may also be obtained by the addition of end reflection corrections.