It may be difficult to appropriately calculate the effectiveness of duct silencers. It is important to select an appropriate silencer and to place them properly within the ductwork layout. Designers should work with an acoustics consultant, or closely with the manufacturer, if the mechanical engineer is not familiar with these installation and calculation issues.

Make sure supply pipes carrying non-potable water are clearly labeled and color-coded to avoid inadvertent cross-connection with potable water lines.

Calculations for “duct breakout noise” should also be made if there is large, high-velocity ductwork in the core learning space or above lay-in tile ceilings. Acoustic duct lagging may be needed in these situations.

The contractor ensures that the correct fixtures have been purchased and any applicable water reuse systems or specified metering systems have been installed. 

Fill out the LEED Online credit form and upload water fixture cut sheets to LEED Online.

Ductless mechanical systems or open-plan classrooms will most likely not conform to the requirements of this credit.

If reusing graywater or rainwater, ensure that key system components such as treatment and cisterns are not removed during value engineering.

The calculation for background noise level can be calculated by a mechanical engineer if they are familiar with the calculations or common software, such as the Trane Acoustics Program (TAP)—which costs $500 per license. ASHRAE has guidelines on running the calculations without software, but these are fairly detailed measurements and a consultant will most likely be needed.

Isolating mechanical equipment noise and installing low-noise and low-velocity equipment, including fans and boxes, will help project teams meet the Background Noise Level requirements. Audiovisual equipment, plumbing, lighting, and noisy sites can also affect background noise but are not required to be considered for this prerequisite but will need to be accounted for in EAc9; Enhanced Acoustical Performance.

Specify signage for water strategies that may require special instructions for use. This may include occupant signage for operating dual-flush toilets, indicating non-potable water, and operational signage for distinguishing pipes carrying reused water.