Dennis Paoletti, FAIA; Principal

Transcription

1 Sustainability and Classroom Acoustics Dennis Paoletti, FAIA; Principal Shen Milsom & Wilke, Inc. Acoustics, Audiovisual, Telecommunications and Security Consultants

2 Classroom Acoustics an Art or Science? An emerging Technology?? An established Technology!!! Standards are not new to acoustics ASTM (American Society of Testing & Materials ANSI( American National Standards Institute) ISO (International Standards Organization) ASHRAE (American Society for Heating, Refrigeration & Air Conditioning Engineers) Technical literature is full of support for good acoustics in classrooms to enhance learning 1928 Knudsen UCLA article

3 Sustainability and Classroom Acoustics Sustainability A new focus Similar to the energy conservation focus of the mid 70 s A search for common ground and mutually agreeable criteria Right now everybody s doing it

4 Sustainability Concepts Cradle to Cradle Federal, State, local efforts ANSI Classroom Acoustics (ADA) CHPS (California High Performance Schools) Healthcare analogy Finding a direct link between good design and better health (learning)

5 Sustainability Acoustics - General Replenishable resources Bamboo Reusable resources Salvaged wood Managed resources Indigenous resources Minimize grass re: mowing / noise

6 Sustainability Acoustics - Accountability Professional responsibility Project must be successful Project and materials must meet criteria There should be no surprises Test data must be provided for evaluation Acoustics is a science not an art!

7 Project Types Education (University, College, High School, Grade School) Performing Arts: Theaters, Auditoria, Entertainment Corporate: Offices, Boardrooms, Training rooms, Health and Recreation, Dining Healthcare: Hospitals, medical office buildings Sports and Recreation: Gymnasia, Arena, Stadia Hospitality: Hotels, Resorts, Conference Centers Public Assembly: Convention Center

8 Classroom Acoustics Design Team DESIGN Client/School District Architect Engineers (Mechanical, Electrical, Plumbing, Structural) Consultants (Acoustics, Audiovisual, Technology, Food, Signage) CONSTRUCTION General Contractor Subcontractors (Mechanical, Electrical, Plumbing, etc.) Specialty Contractors (Audiovisual, Telecommunication, Security, Food)

9 Acoustical Consulting Room Acoustics ( Size, Shape, Proportion, Finishes) Sound Isolation (Exterior-Environmental Noise Control; Interior-Occupied Adjacencies) Noise and Vibration Control (Building Systems HVAC; Plumbing) Audiovisual Systems (Voice Amplification; Music; Playback, Video / Projection, etc.)

10 Terminology Concepts and Sustainability RT (Reverberation Time) Sound absorption requires small particles with many voids to absorb sound energy STC (Sound Transmission Class) -Sound isolation requires density, mass and impervious materials NC / NCB / RC (Noise Criteria) -HVAC background noise requires control od excess noise and vibration

11 Maximum Reverberation Times in the ANSI Standard Volume & Type of Learning Spaces Core spaces (classrooms) volume,10,000ft 3 Includes the standard California classroom Core spaces (classrooms) Volume between 10,000ft3 Oversized classrooms, art rooms and labs Core spaces (classrooms) volume.>20,000ft3 Lecture Halls and Auditoriums All ancillary learning spaces Max (mid freq) Reverb Time 0.6 seconds 0.7 seconds Not specified-but limits are recommended & very important

12 Sustainability Acoustics - Floor Plane Carpet Wood Replenishable sources / managed forests Salvaged / reusable Indigenous sources Underlayment For carpet For hardwood and tile For isolating mechanical equipment For isolating impact and high sound levels Underfloor air distribution..and its related affects on other building systems

13 Sustainability Acoustics Wall Plane Sound absorbing wall treatments Natural / agricultural products Gypsum board for sound isolation; and acoustical privacy Recycled gypsum board Increased airspace and resilient channels in lieu of additional layers of gypsum board

14 Background Noise Levels for Learning Spaces in the ANSI Std Learning spaces: (unoccupied;furnished) Core learning space: Volume<10,000ft 3 Core learning spaces: 10,000ft 3 <vol<20,000ft 3 Core learning spaces: vol>20,000ft 3 & all ancillary learning spaces Corridor not used for formal learning Acoustical critical spaces (e.g. auditoria, lecture & training rooms) Max one-hour-avg A-weighted steady state noise levels 35 dba 35 dba 40 dba 45dBA 25-30dBA

15 HVAC Systems Noise & Vibration Control Setting the appropriate criteria Early planning can help avoid costly solutions/fixes Location of noisy equipment Duct distribution Diffusers/air entrance conditions Careful coordination with the mechanical engineer, structural engineer and architect Review of final construction to review implementation Optional acoustical measurements (commissioning)

16 Sustainability Acoustics Building Systems Electrical Energy efficient electronic ballasts HVAC A challenge Underfloor air distribution Cogeneration Plumbing Waterless urinal!..no plumbing pipes

17 Exterior Noise Varies in time and frequency Assessment difficulties Description difficulties Not the same as HVAC background noise Sound transmission via exterior building envelope (windows)

18 Environmental Noise-Hour Leg Hourly Leq August 8-11, Level (db) :00 AM 1:00 PM 3:00 PM 5:00 PM 7:00 PM 9:00 PM 11:00 PM 1:00 AM 3:00 AM 5:00 AM 7:00 AM 9:00 AM 11:00 AM 1:00 PM 3:00 PM 5:00 PM 7:00 PM 9:00 PM 11:00 PM 1:00 AM 3:00 AM 5:00 AM 7:00 AM 9:00 AM 11:00 AM 1:00 PM 3:00 PM 5:00 PM 7:00 PM 9:00 PM 11:00 PM 1:00 AM 3:00 AM 5:00 AM 7:00 AM 9:00 AM 11:00 AM 1:00 PM Time (Hour)

19 Environmental Noise Level Time History August 8-11, Level (db) :33 AM 12:15 PM 1:57 PM 3:39 PM 5:21 PM 7:03 PM 8:45 PM 10:27 PM 12:09 AM 1:51 AM 3:33 AM 5:15 AM 6:57 AM 8:39 AM 10:21 AM 12:03 PM 1:45 PM 3:27 PM 5:09 PM 6:51 PM 8:33 PM 10:15 PM 11:57 PM 1:39 AM 3:21 AM 5:03 AM 6:45 AM 8:27 AM 10:09 AM 11:51 AM 1:33 PM 3:15 PM 4:57 PM 6:39 PM 8:21 PM 10:03 PM 11:45 PM 1:27 AM 3:09 AM 4:51 AM 6:33 AM 8:15 AM 9:57 AM 11:39 AM 1:21 PM Time (Hour)

20 Exterior Windows Open-they allow noise intrusion Closed-they typically represent the weakest component in the building envelope Note: CHPS promotes window for natural ventilation, day lighting and better indoor environmental quality (IEO) Glazing Configurations Single glazed1/4 plate glass: STC 30 Common thermapane:stc 35 Acoustic Windows: STC Special Windows are required for high noise level environments (i.e. near airports, highways, industrial areas) Check with planning agencies Acoustic Site assessment Cost vs. criteria Other The window frame Laminated glass

21 Sustainability Acoustics - Glazing Fenestration Fresh air exterior noise transmission Use of laminated and double glazing Daylight Natural light glass; sound reflective Interior shading Shades for sun/heat control; and acoustical absorption Minimize size; limit glazing

22 Special Cases High noise level environments (e.g.near airports, highways, etc.) Special educational programs (e.g. hearing impaired, blind, cultural diversity) Design and sustainability issues (e.g. glazing for daylight and natural ventilation)

23 Sustainability Concepts Apply to Acoustics Think full cycle Where does it come from? What is it made from? How will it be used? What will happen to it later? How does it affect other aspects? Preserve resources Reuse materials Minimize material usage