Project Objective
DiGeronimo, Architects and LSG&A, Consulting Engineers in Acoustics, propose professional services as part of an overall strategy to achieve a Speech Interference Level (SIL) of 50 dB within the noise impacted building areas. 

Acoustical Engineering
DiGeronimo and LSG&A staff will inspect the building complex and study existing floor plans and construction details of all exterior walls, windows, vents and the roof.  The DiGeronimo Team proposes to perform the following tasks:

Measured Noise Impact

The DiGeronimo Team will visit the building complex, inspect the existing construction and HVAC systems, and observe typical noise patterns.  During this site visit, engineers from LSG&A will perform sound-pressure-level measurements using precision sound level meters providing calibrated input into digital audio tape recorders.  The measurements will be performed inside and outside at typical, but significantly noise impacted areas.  These measurements will show the existing interior sound levels during noise impact and hence the existing noise reduction provided by the building.

The results of the inspection and measurements will be used to calculate the existing SIL inside the classrooms and other significant areas.  The SIL is the arithmetic average of the sound pressure levels of the 500, 1000, and 2003 hertz octave bands (the critical bands for speech communication).  SIL has been widely used in the evaluation of speech communication, and is well suited to the assessment of noise in areas where speech communication is critical.

Expected Noise Reduction

The DiGeronimo Team works together with client staff and client management to determine the appropriate design goal in terms of SIL and maximum sound level.  The design goal sound level would be based on achieving satisfactory speech communication for the spoken word at a suitable distance during noise source generation.

Based on both the measured noise impact and the expected noise reduction, the DiGeronimo Team develops appropriate noise control recommendations to be incorporated into the design. Where appropriate, LSG&A recommends specific products and manufacturers.

The DiGeronimo Team will review all bids and submissions with respect to the acoustical recommendations for the project.

Success Measurements

At the conclusion of the project, LSG&A will repeat the measurements of the noise levels inside and outside the building complex.  The “after” measurements will be repeated in the same areas as the “before” measurements, by engineers, using similar equipment.

The results of the success measurements will be used to calculate the SIL inside the typical, significant areas of the building complex.  The SIL in each “before” area will be compared to the “after” measurements and to the design goals for the project.

LSG&A will prepare a final report summarizing the results of the success measurements, a comparison with the original measurements, and the acoustic design goals for the project.

Architectural Considerations

Roof Construction

The DiGeronimo Team Approach will review the construction and condition of the existing roof(s) of the building complex.  DiGeronimo will recommend modifications to add sufficient mass to provide a barrier to the sound vibrations.  DiGeronimo contract documents will detail miscellaneous roof penetrations such as pipe vents, ducts and equipment openings to prevent noise infiltration. 

Exterior Windows

The DiGeronimo Team Approach requires replacement of any existing single pane windows with a noise reduction window assembly.  Single pane windows are not adequate to prevent noise impact and are particularly susceptible to infiltration noise in the high frequencies.  The DiGeronimo specified noise reduction window assembly, is two windows separated by a four to six inch air space.  As important as is this dual window assembly, the setting of the unit is equally important.  The window unit head, jamb, and sill must be packed with DiGeronimo specified dense acoustical materials.  Any pinprick size break in this acoustical barrier of window unit and window setting will void the effectiveness of the noise reduction project.  Further complicating the DiGeronimo window design specification, window opening sizes are regulated by code as to clear opening size, sill height, and area to permit access by emergency fire personnel.  DiGeronimo selects divided window pane patterns, window assembly material, and color for aesthetic enhancement of the buildings complex exterior.

Exterior Doors

The DiGeronimo Team Approach requires replacement of existing exterior doors with acoustical rated doors.  A source of sound infiltration occurs through and around doorways.  DiGeronimo specifies each door for ability to reduce sound transmission.  DiGeronimo contract documents design door frames and specify dense acoustical sealants for an effective acoustical barrier.  DiGeronimo selects exterior door patterns, materials, and color for aesthetic enhancement of the buildings complex exterior.

Life Safety Upgrade

The building code mandates life safety upgrade when renovating buildings.  The DiGeronimo Team Approach includes analysis of required code upgrades affected by the noise reduction project.  DiGeronimo contract documents include the necessary life safety upgrades.

Vents and Miscellaneous Openings

The DiGeronimo Team Approach includes examination of any and all penetrations of the exterior wall, for the possibility of noise infiltration.  Fan openings to the outside are sources of sound penetration.  DiGeronimo specifies special acoustically baffled vents to allow air to enter the building complex while shielding our noise vibrations.  DiGeronimo specifies acoustical baffles and insulated acoustics ductwork.  DiGeronimo selects acoustically baffled components for aesthetic compatibility to building complex exterior material.

Integrated Architectural/Engineering Solution

The DiGeronimo Team seeks out solutions which both solve the acoustical problem and integrate these into a pleasing aesthetic in a cost effective manner.  The major source of noise infiltration is the roof, windows, and building envelope penetrations.  At the same time building code requirements demand fresh air changes.  The DiGeronimo design solution integrates the simultaneous need for acoustical isolation and for ventilation.  In the void space between the old and new, DiGeronimo engineers design a new air exchange ventilation system which will provide tempered fresh air, ducted into the occupied spaces through new, acoustically treated openings.  DiGeronimo engineers carefully specify quiet operation units.  The DiGeronimo design precautions successfully reduce all noise sources.  DiGeronimo design engineers do not want to add interior noise, negating exterior sound isolation achieved.  DiGeronimo engineers examine the existing building ventilation system, and if adequate, the existing system can remain.

Approximate Work Schedule

The DiGeronimo Team construction planning effort requires that heating systems are shut down, roof modifications are made, and exterior windows are replaced.  DiGeronimo specifies a schedule with the contractor, which will minimize the impact of these disruptive construction activities.  DiGeronimo specification for construction scheduling identifies spaces the client will arrange to vacate, at the client’s convenience.  Vacating some spaces will allow the contractor unoccupied space to perform construction operations unimpeded.  DiGeronimo specification for construction scheduling enables construction to occur around normal client building complex occupancy routines, with minimal disruption.

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