Acoustical Engineering Solutions

Transcription

1 Acoustical Engineering Solutions

2 Noise & Vibration Control in Wood Framed, Residential Structures By Scott Harvey, PE, INCE Bd. Cert. Phoenix Noise & Vibration Frederick, Maryland

3 Copyright Materials This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. Phoenix Noise & Vibration, LLC 2016

4 Learning Objectives Acoustic Terminology Codes relating to multifamily noise control Control indoor noise transmission mechanical noise outdoor noise Apply principals in daily designs Always remembering

5 That they make guitars and pianos out of wood, don t they

6 Overview Codes & Terminology Room to Room Noise Control Wood Structures Mechanical Noise Control Outdoor to Indoor Noise Control

7 Codes Building Officials and Code Administrators International (BOCA) (1999) International Building Code (20xx) International Residential Code International Code Council Green Construction Code

8 Agency Unit Types STC/ASTC IIC/FIIC BOCA (1999) 45/na 45/na IBC Between Units, Corridor, or Common Spaces 50/45 50/45 IRC Living Units 45/na 45/na Group R from Aor F 60/55 ICC Group R from R, B, I or M 50/45 Group R Condos from R Condos, B, I, M or R 55/50 Group R from R, A1, A2, A3, B, E, I, or M 50/45 DC Dwelling Units from each other and from public service areas 50/45 50/45 Dwelling units from Group A 2 55/50

9 Codes Other codes or guidelines deal with: Outdoor to indoor noise control Mechanical impact upon adjacent properties Primarily today, let us concern ourselves with interior noise.

10 Terminology FSTC dba ASTC IIC STC NC OITC

11 Terminology Loudness measured in decibels (db) db = 10 x log(pressure 2 /refpressure 2 ) Human Range: 0 to 130 db A weight to simulate human hearing dba

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13 Terminology Why db??? Example of the logarithmic nature: Change in db Subjective Response 3 db Barely Perceptible 5 db Clearly Perceptible 10 db Twice as Loud Eases Comparisons: 30 to 33 = Barely Perceptible 90 to 93 = Barely Perceptible

14 Terminology Everything is based upon the decibel scale It s the fundamental unit of measure

15 Terminology There are noise barriers and there are noise absorbers. Barriers are not absorbers. Absorbers are not barriers. Many times the absorber is somewhat acoustically transparent. Barriers are generally composed of dense, heavy material layers. (Quiz Later)

16 Quiz Barrier or Absorber? Barrier

17 Quiz Barrier or Absorber? Absorber

18 Quiz Barrier or Absorber? Barrier

19 Quiz Barrier or Absorber? Absorber

20 Quiz Barrier or Absorber? This is of absolutely no use to the acoustician except to keep beer cold!

21 Room to Room Noise Control

22 Teminology Sound Transmission Class (STC) Impact Insulation Class (IIC)

23 Terminology Sound Transmission Class (STC) a single number rating of the partition s ability to block speech frequencies from one side to another.

24 Room to Room STC Applies to Both Floor/Ceiling Systems And Walls

25 Room to Room STC ASTC Subjective Description Most sentences clearly understood Speech can be heard with some effort Loud speech can be heard with some effort Loud speech essentially inaudible Loud music heard faintly 75+ Most noises effectively blocked Credit: Architectural Acoustics: Principles and Design 1999

26 Room to Room Quiz

27 Room to Room STC developed for speech, applied to many other noise sources such as: Mechanical Transportation Music Warning: Not always accurate for these other sources

28 Room to Room Impact Insulation Class (IIC) A single number rating used to compare the effectiveness of floor/ceiling assemblies in providing reduction of impact generated sound such as footsteps.

29 Room to Room IIC Only Applies to Floor/Ceiling Systems

30 Room to Room The popularity of hard surfaced floors in condominiums has brought a lot of attention to IIC ratings. Most Any Carpet and pad > 60 IIC Hard floors < 40 IIC But Remember IBC standard is 50 IIC

31 Application 50 to 55 IIC Depending upon Underlayment

32 Underlayments: Choose Wisely! There are numerous underlayments on the market Many are copies of originals Make sure there is a test from a third party laboratory Make sure the test is of your system

33 So you go on line to buy some underlayment

34 No, No, No Get documentation!

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36 Underlayments: Choose Wisely! Make sure the test is of your system!

37 Application One cost effective way to add STC and IIC points to a wall or floor/ceiling system is through the use of Resilient Channel Cost effective, but NOT SO SIMPLE (This really needs much more time )

38 Resilient Channel Single Legged, RC 1 (Dietrich RC Deluxe) Double Legged, RC 2

39 Resilient Channel Works in floor/ceilings too

40 With The Double Legged

41 Resilient Channel Yes!

42 The #1 Problem with RC Courtesy of Pliteq Inc.

43 Resilient Channel NO s!

44 Quiz: What s the Difference? Insert UL U311 detail

45 For Very High STC & IIC

46 Mechanical Noise A forest of condenser on the roof directly above the most expensive units in the building.

47 Condenser Noise Location, location, location Above non noise sensitive rooms such as corridors Aids in the air borne noise But structure borne not so much

48 Condenser isolation

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50 Outdoor to Indoor Noise Control

51 Transportation Noise Planes, Trains, & Automobiles On site measurements Computer Modeling HUD Noise Guidebook Ldn or Leq in dba

52 Local Transportation Interior Noise Level Requirements State/City/County Roadway/Railway Airport Virginia 45 dba Leq NA HUD 45 dba Ldn 45 dba Ldn Anne Arundel 45 dba Leq 45 dba Ldn Howard 45 dba Ldn 45 dba Ldn DC NA NA Baltimore City NA NA Fairfax 45 dba Ldn 45 dba Ldn Loudoun 45 dba Leq 45 dba Ldn HUD 45 dba Ldn 45 dba Ldn

53 Outdoor to Indoor Transportation Noise Computer Modeling Building Shell Analysis Common Building Elements Windows and Doors: The Weak Link OITC

54 Building Shell Analysis Calculates a room s interior noise level based upon: Exterior Noise Level Composite STC Rating Windows, Doors Walls, Roof Miscellaneous Room Size & Volume Room Absorption Can be either very general or very detailed

55 Exterior Wall STC Building Element STC Rating Common to All Constructions Exterior Walls Brick 56 Vinyl Siding 39 Vinyl Siding w/rc 45 Fiber Cement (Hardi) Siding 43 Fiber Cement w/ RC 47 2 x 4 wood studs, an exterior layer of ½ OSB or plywood, 3 of fiberglass batt insulation, 5/8 interior layer of drywall

56 Window & Door STC Building Element STC Rating Construction ½ Insulated Window 28 1/8 glass, ¼ air space, 1/8 glass 1 Insulated Window 35 ¼ glass, ½ air space, ¼ glass 5/8 Laminated Insulated Window 35 Two 1/8 panes laminated together, ¼ air space, 1/8 glass Standard Patio Door 29 ½ glass mounted in polystyrene frame Upgraded Patio Door 36 1 ; dual glazed unit composed of 3/8 laminated glass, ½ air space, and 1/8 double strength glass

57 Windows and Doors: The Weak Link

58 OITC Outdoor Indoor Transmission Class: an A weighted single number rating of the transportation sound reduction effectiveness of a partition that separates an indoor space from the outside. STC Speech Frequencies OITC Transportation Frequencies Window STC Rating OITC Rating ½ Insulated /8 Laminated, Insulated 35 31

59 Outdoor to Indoor Design Challenges Restrictions on Exterior Façade Finishes Lots of Glass High STC Rated Windows and Doors = $$$ Green Building Design Bigger Windows Fresh Air Openings

60 In Review Codes & Terminology Room to Room Noise Control Wood Structures Mechanical Noise Control Outdoor to Indoor Noise Control

61 Thank You for the Attention! Questions? Earplugs? Discussion?

62 Acoustical Engineering Solutions