scope:

This standard includes sound levels from most but not all components in the air distribution system. Air Terminals, air outlets and the low pressure ductwork which connects them are considered as sound sources and are the subject of this Standard.

This Standard does not make provisions to estimate space sound level contributions from the central system fan, ductwork upstream of the Air Terminal, equipment room machinery or exterior ambient sound.

This Standard is not currently applicable for underfloor radiated or discharge sound calculations.

AHRI Standard 880 does not provide for determination of sound power in the 63 Hz octave band. These products do not contribute significantly to the sound levels in occupied spaces in the 63 Hz octave band. The dominant source of sound levels in occupied spaces in the 63 Hz band is controlled by the primary air supply system. Since AHRI Standard 885 could be used to determine occupied space sound levels from the primary air supply system, data is provided where available in the 63 Hz octave band.

The methods described in this Standard can be used to identify acoustically critical paths in the system design. The design effects of inserting alternative components and changes in the system can be evaluated. The accuracy of evaluating the difference in sound pressure between two alternatives is greater than individual estimations.

Purpose. The purpose of this standard is to provide a consistent industry-accepted method for estimating Sound Pressure Levels in a conditioned occupied space for the application of Air Terminals and air outlets.

Intent. This standard is intended for the guidance of the industry, including manufacturers, engineers, installers, contractors and users.

Review and Amendment. This standard is subject to review and amendment as technology advances.