Noise and Vibration Control in Wood-Framed, Multi-Family Buildings

Transcription

1 Noise and Vibration Control in Wood-Framed, Multi-Family Buildings Presented by Scott Harvey, PE, INCE Bd. Cert. Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

2 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Course Description Learn to avoid common comfort-related pitfalls in woodframe multi-family projects. Presented by an acoustics and vibration expert, this webinar will cover practical information related to code requirements, acoustical barriers, and high-performing, acoustically-rated wall and floor assemblies. Recommendations to avoid common pitfalls such as flanking paths will be presented along with example projects featuring real-world acoustical issues and solutions. Vibration and associated noise issues related to mechanical equipment will also be addressed, with an emphasis on how to avoid them through proper isolation design.

4 Learning Objectives 1. Identify potential comfort issues in multi-family and mixed-use buildings and how to address them through proper building design. 2. Review code requirements for acoustical design in multi-family and mixed-use buildings. 3. Highlight options for high-performing, acousticallyrated wood-frame assemblies, including walls and floors. 4. Discuss solutions to potential vibration-related complaints associated with mechanical equipment in wood-frame structures. Always remembering

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

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

7 Codes & Terminology

8 Codes Building Officials and Code Administrators International (BOCA) (1999) International Building Code (2018) International Residential Code International Code Council Green Construction Code

9 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 A or 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

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

11 Terminology FSTC dba ASTC IIC STC NC OITC

12 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 Named for Alexander Graham Bell

13

14 Why db??? Compresses a large range of numbers to a more manageable range. 20 micropascals to 20,000,000 micropascals becomes 0 to 120 db

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

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

17 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)

18 Quiz Barrier or Absorber? Barrier

19 Quiz Barrier or Absorber? Absorber

20 Quiz Barrier or Absorber? Barrier

21 Quiz Barrier or Absorber? Absorber

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

23 Room to Room Noise Control

24 Side track Air Borne vs. Structure Borne Noise

25 Air Borne and Structure Borne Air borne noise and structure borne noise are really descriptors of the pathways by which sound arrives at the listener from the noise source.

26 Air Borne Noise Path The sound heard in the room which contains the source is transmitted through partitions and becomes air borne noise in other rooms. Generally air borne is sound or noise Example:

27

28 To Control Air Borne Noise Remember: Use noise barriers to control or block air borne noise from other locations.

29 Structure Borne Noise Path Vibration from the source is transmitted directly to the building structure, propagates through that structure and becomes audible sound in another part of the building. Generally structure borne is vibration Examples:

30 Pumps on the floor above, or

31 PUMPS on the floor above.

32 Structure Borne Noise 1. Ideally, if the vibrating object did not touch anything there would be no structure borne noise 2. Since #1 is pretty much a no go, proceed to #3 3. Introduce vibration isolation Hard surfaced floor underlayments Mechanical equipment on springs or rubber In order to ISOLATE the vibrating or impacting object from the structure. (more later)

33 A little quiz Is it Airborne Noise? Or Structure Borne?

34 Back on the main track

35 Terminology Sound Transmission Class (STC) Impact Insulation Class (IIC)

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

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

38 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 A or 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

39 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

40 Room to Room Quiz

41 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

42 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.

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

44 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 A or 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

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

46 Application 50 to 55 IIC Depending upon Underlayment

47 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

48 So you go on line to buy some underlayment

49 No, No, No Get documentation!

50

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

52 For Very High STC & IIC in Floor Ceiling

53 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 )

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

55 Resilient Channel Works in floor/ceilings too

56 With The Double Legged

57 Resilient Channel Yes!

58 The #1 Problem with either RC Courtesy of Pliteq Inc.

59 Resilient Channel NO s!

60 Quiz: What s the Difference?

61 34 STC 36 STC 38 STC

62 40 STC 54 STC 50 STC 57 STC

63 Mechanical Noise Control

64 Rating Mechanical Noise Loudness Soft Quiet Loud Noisy Quality of Noise Rumble Roar Hiss Tonal

65 Background Noise Quantification Single number ratings describing the relative loudness and speech interference properties of a given noise spectrum Used to specify background noise levels for various space uses, mainly HVAC and mechanical noise Again, all based upon the decibel scale.

66 Background Noise Measures Noise Criteria (NC) Simple but, No assessment of sound quality Room Criteria (RC(N)) More difficult to comprehend Evaluates sound quality Diagnostics

67 Mechanical Noise Measures Method Loudness Quality dba - NC - RC(N)

68 ASHRAE* Recommended Background Levels Room Type NC/RC dba Residences, Apartments, Condominiums Living areas Bathrooms, kitchens, utility rooms Hotels/Motels Individual rooms or suites Meeting/banquet rooms Office buildings Executive and private offices Conference rooms Open Plan offices * Values taken from 2011 ASHRAE Applications Handbook, Chapter 48, Table 1.

69 Significant Sources

70 Find the big stuff because. Bigger is louder!

71 Emergency Generators

72 Chillers

73 Rooftop AHU s

74 Pumps

75 Exhaust Fans

76 Elevator Machinery

77 Rooftop Condensing Units

78 Bigger is relative The smaller stuff can be annoying too but it is easier to fix after the fact...unless you built 300 units with noisy water source heat pumps

79 Noise Control Schemes

80 The Best Method of Noise Control is at the source Buy the quieter unit to begin with Increase the distance between source and receiver Schedule operations of the unit during non-noise sensitive times But then what?

81 Courtesy of ASHRAE

82 Courtesy of ASHRAE

83 Mechanical Vibration Structure Borne Proper Isolation Springs Pads Roof Curbs

84 Page 42, Chapter 47, 2003 ASHRAE Handbook

85 Equipment Type Structural Support Base Type Isolator Type

86 or Pumps on the floor above.

87

88 Typical Pump Isolation

89

90

91

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

93 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

94

95 Not just the unit, ducts and piping too!

96

97 If the perceived vibration seems too high ISO has developed a series of curves to evaluate vibration that is measures in the floor of an occupied room. These are guidelines, not code. Local codes may or may not be available. Residential night is 100 micrometers/second, ½ of the daytime limit.

98 Case Study Hydraulic Elevator Pump Unit Directly beneath living unit within a retirement community Only means of isolation was in the floor

99

100

101

102 In Review Codes & Terminology Mechanical Noise Control Wood Structures Room to Room Noise Control

103 QUESTIONS? This concludes The American Institute of Architects Continuing Education Systems Course Scott Harvey, PE, INCE Bd. Cert. Phoenix Noise & Vibration, LLC