Contents BB93 Acoustic Design for Schools

Transcription

1 Contents BB93 Acoustic Design for Schools BB93 Background Noise Sound Insulation Rooms Acoustics - Reverberation times

2 Internal Noise Level Example Llwynu School

3 Internal Background Noise BB93 Internal noise levels are the combined levels from: External noise, e.g. Traffic, railways, aircraft, industrial noise Mechanical services, e.g. ventilation systems, plant. Excluded noise sources: Teaching activities within the school premises including playgrounds Equipment noise, e.g. from machine tools, computers, fume cupboards

4 The Site Llwynu Primary School Position 1 and Children Shouting Into the Microphone db(a) Micro Phone Moved to Position 2 db(a) :00 08:15 8:45 9:15 9:45 10:00 10:15 10:45 11:15 11:45 12:15 12:45 13:15 13:45 14:00 14:15 14:45 15:15 15:45 16:15 16:45 Time

5 Sound Resistance of the Facade Vented facades will provide 10 to 15 db of sound insulation Sealed facades will provide 20 to 35 db of sound insulation

6 Summary of Internal Noise Levels 30 db Laeq 35 db Laeq 40 db Laeq 45 db Laeq Exemplar Designs Alsop

7 Contents BB93 Acoustic Design for Schools BB93 Background Noise Sound Insulation Rooms Acoustics - Reverberation times

8 Sound Insulation - Partitions

9 Specification of Sound Insulation BB93 Table 1.2: Performance standards for airborne sound insulation between rooms - minimum weighted BB93 standardized level difference, DnT (Tmf,max),w

10 Specification of Sound Insulation BB93 Table 1.1: Room classification for the purpose of airborne sound insulation Table 1.2

11 Sound Insulation BB93 Circ ulation Spac e Circulation Space Classroom Workshop Classroom Store room La b Sp a c e La b Sp a c e Circulation Space Wo rkshop Circulation Space 40 db Rw - All Partition to Circulation space (with the exceptions of music space) 40 db Rw - All Space to Store Rooms 40 db Dw - Science Lab to Science Lab 45 db Dw - Science Lab to Classroom 45 db Dw - Classroom to Classroom 50 db Dw - Workshop to Workshop 50 db Dw - Workshop to Science Lab 55 db Dw - Workshop to Classroom (not recommended)

12 Example Llwynu School

13 The Conversion of On Site Levels to Construction Types R W Lab Tested Sound Insulation D W On Site Sound Insulation level D w = R w + 10log(3TS/V) + X (db) V is the receiving room volume, S is the partition area T is the room finishes X is a safety factor (typically 5 db and 12 db fo a folding partition)

14 The Conversion of On Site Levels to Construction Types Large Room Soft Finishes Low Noise Large Room Hard Finishes Medium Noise Small Room Soft Finishes High Noise

15 The Conversion of On Site Levels to Construction Types Low levels of sound Insulation Lower levels of sound Insulation

16 The Conversion of On Site Levels to Construction Types R W Lab Tested Sound Insulation D W On Site Sound Insulation level D w = R w + 10log(3TS/V) + X (db) V is the receiving room volume, S is the partition area T is the room finishes X is a safety factor (typically 5 db and 12 db fo a folding partition)

17 Sound Insulation - Partitions

18 95 m10 Rw40dB 12 m 0m10 Rw45dB m 120m10m Rw m50db 215m 215m Rw5 db Dens edense Light 142m 10/50/10mDense 10/50/ mde 10 nse4 L Stud,50 Onelaye rofwal mineral wol board,7 Twola Stud 0m board, yerofwall 70m TwStu boad,50mineral olayerofwall wol rd,70m Twolayerof Soundblc,92m Stud,75min eral wol 15kg/m 10m 2LightweightBlock 10m 15kg work LightweightBlo /m2 ckwork kg/m 2mmDenseSolid Blockwork 10/50/10m mdensesolidb lockwork486kg 2/m 40 2*215*215Dense Hollow/cellular 10/50/10m mdenseholow/ celular428kg/m kg/m mmlightweight Blockwork 392mLigh tweightblockwork 257kg/m 257 kg/m 2 Sound Insulation - Partitions A significant difference must be made to improve the sound insulation of a partition. 6 db is approximately equivalent to doubling your efforts in terms of design. Rw 40 db Rw 45 d B Rw 50 d B Rw 55 d B 95 mm 100 mm 120 mm 100 mm 120 mm 100 mm Dense 215 mm Lig ht 142 mm 100/50/100 mm Dense 440 mm Light One layer of wall board, 70mm Stud, 50mm mineral wool 100mm Lightweight Blockwork kg/m Two layer of wall board, 70mm Stud 100mm Lightweight Blockwork kg/m Two layer of wall board, 70mm Stud, 50mm mineral wool 100mm Dense Solid Blockwork kg/m Two layer of Soundblc, 92mm Stud, 75 mm mineral wool 2 100/50/100mm Dense Solid Blockwork 486 kg/m 2 392mm Lightweight Blockwork 257 kg/m 215mm Lightweight Blockwork kg/m

19 Contents BB93 Acoustics Design for Schools BB93 Background Noise Sound Insulation Rooms Acoustics - Reverberation times

20 Room Specifications Table 1.5: Performance standards for reverberation in teaching and study spaces mid-frequency reverberation time, Tmf, in finished but unoccupied and unfurnished rooms

21 Reverberation

22 Case Study Dartington School

23 Dartington School & BB93 Requirements BB93 Acoustic Design for Schools requires that Primary School classrooms achieve a reverberation time of 0.6 seconds or less. Such to comply with this requirement, classrooms require 62 Sabine meters of treatment, where 1 Sabine meter is equivalent to providing 100% absorption over 1 meter.

24 Effects of Carpet Modeled data shows that the wood finishes, windows, doors and other elements in the rooms provided 15 Sabine meters. Required Additional Levels of Treatment with Low Grade Carpet High Grade Carpet 36 Sabine Meters 28 Sabine Meters 3D Visual Illustrating the Acoustic Light Fittings Take for the Acoustic Model

25 Visual of Proposed Treatments Acoustic beams formed from mineral wool with a colored or plain finish. One of the advantages of this form of absorption is that absorption is provided by the four sides of the beam. Beams 8m long, 200mm wide, 350mm high Low Grade Carpet High Grade Carpet 4 Rows Per Classroom 3 Rows Per Classroom Acoustic Beams within Classrooms Acoustic Light Fittings these light fittings contain wings on each light providing acoustic absorption. Acoustic Light 8m long, 600mm wide Low Grade Carpet High Grade Carpet 4 Rows Per Classroom 3 Rows Per Classroom Whitecroft Acoustic Lights

26 Visual of Proposed Treatments Ecophon Master Solo S is a new suspended acoustic panel. These panels benefit from absorption being provided by both sides of the panel. Ceiling Panel 1200mm, 1200m, 40mm Low Grade Carpet High Grade Carpet 17 Panels 13 Panels Ecophon Master Solo S Eurban Acoustic Panels these panels contain a wooden finish. A larger area is needed compared to must other finishes as the perforated wood reduces the effectiveness of this product. Eurban Acoustic Panels Low Grade Carpet High Grade Carpet 60m 2 47m 2 Eurban Acoustic Panels

27 Visual of Proposed Treatments Acoustic Art Work works by covering mineral wool with an acoustically transparent fabric. This form of absorption can be an interesting method of adding colour, texture, themes and shapes within a classroom. Art work Low Grade Carpet High Grade Carpet 42m 2 32m 2 Image top Such to provide acoustic absorption, an outline of an animal and such like could be stuck to the soffit of classrooms. Alternatively, a large graphic could be applied to classroom soffits bottom Image

28 Visual of Proposed Treatments Acoustic Lights

29 Visual of Proposed Treatments Acoustic Lights and Beams

30 Visual of Proposed Treatments Acoustic Beams

31 Visual of Proposed Treatments Acoustic Beams

32 Interior Design It is important to note that there are almost endless options in terms of design with respect to soft finishes. The next few pages of this report provides some of these options. Maxine Bennett Wylde IA Many thanks to Maxine Bennett for providing many of the images within this report. 41 Montpelier Court Station Road Montpelier Bristol BS6 5EA T F W

33 Creative Designs Eurban Acoustic Panels Perforated wood paneling to the soffit of a space. The perforated paneling is provided in this case by Eurban.

34 Creative Designs Acoustic Beam Colorful and textured finishes providing acoustic absorption. Absorption is provided by cloth covered mineral wool panels.

35 Creative Designs Acoustic Art Work A MACH Acoustics/ Wylde IA project, where the art work was made to provide high levels of acoustic absorption.

36 Creative Designs Acoustic Art Work A MACH Acoustics/ Wylde IA project, where acoustic absorption was placed above the raft ceiling and incorporated into the textured perforated art work on the wall..

37 Creative Designs Perforated Walls An example of acoustic treatment being provided in the form of a perforated wall.

38 Creative Designs Acoustic Wall Paper A mural across the length of a wall, providing both a feature and acoustic absorption..

39 Creative Designs Acoustic Art Work Fabric coloured wall panels added to a multi coloured wall.

40 Creative Designs Barasol Ceiling and Lights A MACH Acoustics and Wylde IA project, where the flat shiny ceiling and illuminated light ways provided effective forms of acoustic absorption.