What is BS 4857-2 - Acoustic testing and rating of terminal reheat units about?
Terminal reheat units are a type of air handling system that are generally used in conjunction with constant air volume (CAV) and variable air volume (VAV) systems, for efficient reheating of air in the occupied space.
BS 4857 is a British Standard that discusses the methods for testing and rating of terminal reheat units, for air distribution systems. The main aim of the BS 4857 series is to provide manufacturers with best industry testing methods to determine the performance of terminal reheat units.
BS 4857-2 is the second part of BS 4857 which deals with methods of acoustic testing and rating of terminal reheat units, defined in Part 1 of the standard, for:
- Static terminal attenuation
- Sound generation, upstream and downstream of the unit
- Radiation of sound from the casing
Who is BS 4857-2 - Acoustic testing and rating of terminal reheat units for?
BS 4857-2 on acoustic testing and rating of terminal reheat units is relevant to:
- Manufacturers of terminal reheat units
- Manufacturers of ventilation and air-conditioning systems
- Manufacturers of HVAC application
- Mechanical engineers
- Quality control and testing authorities
Why should you use BS 4857-2 - Acoustic testing and rating of terminal reheat units?
Acoustic testing or acoustic emission testing is the measurement of sound emissions radiating from the equipment. This assessment is essential to determine the noise generated by devices/units to ensure that it does not impair performance and operational efficiency of the machine or equipment.
BS 4857-2 provides best industry guidance two laboratory methods for determining the mean sound power radiated by a device, machine, component or sub-assembly in successive frequency bands. While other methods could be used to measure the noise emitted, the methods particularly advantageous for rating the sound output of sources which produce steady noise and for which directivity information is not required.
The sound power level can be determined from the mean sound pressure level in the test room by either the direct method or substitution method, guidance on which is covered in BS 4857-2.
As a result, if you are a manufacturer of terminal reheat units, compliance with BS 4857-2 can help determine whether your products are reliable and effective at the point of use, and thereby minimize the risk of end-application failures.
