Internally generated noise

BACKGROUND

Electronics, HVAC systems, mechanical equipment and other noise-emitting office devices, as well as occupants themselves, can be sources of indoor noise. As offices and workspaces are increasingly designed to promote employee interaction, occupants can experience decreased levels of privacy and acoustic comfort, especially when users with different job types share a space. Office noise can lead to decreased productivity, especially in open-plan offices where aural distractions and interruptions from other employees are frequent. Additionally, studies show that exposure to noise generated within the building can lead to reduced concentration and mental arithmetic performance, and increased distraction due to reduced speech privacy.

Nervous

Endocrine

Cardiovascular

Part 1
Acoustic Planning

VERIFICATION

An acoustic plan is developed that identifies the following spaces and potential sources of disruption:

a.⁹⁰

Loud and quiet zones.

Noisy equipment in the space.

Documents
Professional Narrative

Part 2
Mechanical Equipment Sound Levels

VERIFICATION

The mechanical equipment system meets the following requirements once interior build-out is complete in the following spaces:

a.⁹⁰

Open office spaces and lobbies that are regularly occupied and/or contain workstations: maximum noise criteria (NC) of 40.

b.⁹⁰

Enclosed offices: maximum noise criteria (NC) of 35.

Conference rooms and breakout rooms: maximum noise criteria (NC) of 30 (25 recommended).

On Site
Performance Test

Part 3
Mechanical Equipment Sound Levels in Sensitive Rooms

VERIFICATION

The following requirement is met in the bedrooms, dining rooms, living rooms, and studies:

a.¹³¹

The maximum background noise level in the home or unit due to interior noise sources (HVAC systems, lighting, and other building services operating simultaneously) is less than or equal to 40 dBA.

On Site
Performance Test

Part 4
Best-Practice HVAC Installation

VERIFICATION

The following requirements are met:

a.¹³¹

Ducts are securely attached with no loose connections between sections.

b.¹³¹

Fan housing is securely anchored.

c.¹³¹

Damper flaps fully close, without any visible airspaces around the perimeter of the flap.

Letter of Assurance
Contractor

Part 5
HVAC Sound Ratings

VERIFICATION

The following requirements are met in all bedrooms, dining rooms, living rooms, and studies for all fans except HVAC air handlers and remote-mounted fans that are located outside habitable spaces with at least 1.2 m [4 ft] of ductwork between the fan and the intake grill:

a.¹³¹

Intermittent ventilation fans with a maximum rated airflow at or below 11 m³/min [400 cfm] have a maximum sound rating of 1.5 sones.

b.¹³¹

Continuous ventilation fans have a maximum sound rating of 0.7 sones.

Letter of Assurance
MEP

Part 6
Noise Criteria in Schools

VERIFICATION

Each regularly occupied space must meet the following noise criteria while unoccupied, as measured in the geometric center of the room:

a.¹²⁵

Classrooms: maximum noise criteria (NC) of 35.

On Site
Performance Test

Part 7
Disruptive Music Limitation

VERIFICATION

If music is played in the space, sound levels may not exceed the following:

a.¹⁷³

7 decibels (dBA) above the ambient sound pressure level when measured at a minimum distance of 4.5 m [15 ft] outside of the entrance to the space.

On Site
Performance Test

	Core & Shell	New & Existing Buildings	New & Existing Interiors
Part 1: Acoustic Planning	-	P	P
Part 2: Mechanical Equipment Sound Levels	O	P	P

	Commercial Kitchen	Education	Multifamily Residential	Restaurant	Retail
Part 1: Acoustic Planning	P	P	-	P	P
Part 2: Mechanical Equipment Sound Levels	-	P	-	-	-
Part 3: Mechanical Equipment Sound Levels in Sensitive Rooms	-	-	O	-	-
Part 4: Best-Practice HVAC Installation	-	-	O	-	-
Part 5: HVAC Sound Ratings	-	-	O	-	-
Part 6: Noise Criteria in Schools	-	P	-	-	-
Part 7: Disruptive Music Limitation	-	-	-	P	-

Verification Methods Matrix

	Letters of Assurance	Annotated Documents	On-Site Assessment
Part 1: Acoustic Planning		Professional Narrative
Part 2: Mechanical Equipment Sound Levels			Performance Test
Part 3: Mechanical Equipment Sound Levels in Sensitive Rooms			Performance Test
Part 4: Best-Practice HVAC Installation	Contractor
Part 5: HVAC Sound Ratings	MEP
Part 6: Noise Criteria in Schools			Performance Test
Part 7: Disruptive Music Limitation			Performance Test

Standard Citations

90

U.S. General Services Administration Center for Workplace Strategy Public Buildings Service. Sound Matters: How to Achieve Acoustic Comfort in the Contemporary Office. Washington, D.C.: 2012: 11, 29, 32, 33, 36.
75.1.a	The General Services Administration's Sound Matters recommends to carefully consider the effect on neighboring workstations when locating supporting activities, i.e. copier rooms, coffee bars, entries to conference rooms.
75.2.a	The General Services Administration's Sound Matters recommends a background noise maximum of NC 40 for open plan workspaces.
75.2.d	The General Services Administration's Sound Matters recommends a background noise maximum of NC 20 for teleconference facilities.
75.2.b	The General Services Administration's Sound Matters recommends a background noise maximum of NC 35 for private offices.

**125**

**ASHRAE. Noise and Vibration Control. In Owen M, ed. ASHRAE Handbook - HVAC Applications. 2011 ed. Atlanta, GA: ASHRAE; 2011.**
75.6.a	ASHRAE recommends a noise criteria (NC) less than 35 in school classrooms.

**131**

**U.S. Green Building Council. Pilot Credit: Acoustic Comfort. http://www.usgbc.org/node/4631859?return=/credits. Published 2013. Accessed December 10, 2014.**
75.3.a	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that the max. background noise level due to interior noise sources cannot exceed 40 dBA based on peak hr Leq tested in acoustically sensitive rooms.
75.4.c	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that damper flaps close fully, with no visible airspaces around the flap.
75.4.a	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that ducts are securely attached with no loose connections between sections of ductwork.
75.4.b	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that the fan housing is securely anchored.
75.5.b	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that continuous ventilation fans have a max. sound rating of 1.5 sones in acoustically sensitive rooms.
75.5.a	The LEED v4 credit for Acoustic Comfort for homes sets 2 options for the LEED point, one of which requires that intermittent fans have a max. sound rating of 1.5 sones (unless their max. rated airflow exceeds 400 cfm) in acoustically sensitive rooms.

**173**

**New York City Department of Environmental Protection. A Guide to New York City's Noise Code. http://www.nyc.gov/html/dep/pdf/noise_code_guide.pdf. Published 2014. Accessed April 16, 2015.**
75.7.a	The NYC DEP's Guide to the NYC Noise Code states that music heard on the street may not exceed 7 decibels over the ambient sound level, as measured on the street or public right-of-way 15 ft or more from the source from 10PM-7AM.

Internally generated noise

Internally generated noise

BACKGROUND

Part 1 Acoustic Planning

Part 2 Mechanical Equipment Sound Levels

Part 3 Mechanical Equipment Sound Levels in Sensitive Rooms

Part 4 Best-Practice HVAC Installation

Part 5 HVAC Sound Ratings

Part 6 Noise Criteria in Schools

Part 7 Disruptive Music Limitation

Applicability Matrix

Verification Methods Matrix

Standard Citations

Part 1
Acoustic Planning

Part 2
Mechanical Equipment Sound Levels

Part 3
Mechanical Equipment Sound Levels in Sensitive Rooms

Part 4
Best-Practice HVAC Installation

Part 5
HVAC Sound Ratings

Part 6
Noise Criteria in Schools

Part 7
Disruptive Music Limitation