Internally generated noise

In addition to electronics, HVAC systems and other office devices, occupants themselves are major 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 different types of users share a space.

This feature reduces distractions and enables speech privacy without impairing collaboration. These requirements can be met by limiting the amount of sound emanating from building systems and creating quiet zones for activities that require freedom from distraction.

Part 1: Acoustic Planning

An acoustic plan is developed that identifies the following:

a.⁹⁰ Loud and quiet zones of work.

b. Noisy office equipment such as copy machines and paper shredders.

Part 1: Ceilings

The following spaces, if present, have ceilings that meet the specifications described:

a.⁹⁰ Open office spaces: NRC of at least 0.9 for the entire surface area of the ceiling (excluding lights, skylights, diffusers and grilles).

b.⁹⁰ Conference and teleconference rooms: NRC of at least 0.8 on at least 50% of the surface area of the ceiling (excluding lights, skylights, diffusers and grilles).

Part 2: Mechanical Equipment Sound Levels

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

a.⁹⁰ Open office spaces: maximum noise criteria (NC) of 40.

b.⁹⁰ Enclosed offices: maximum noise criteria (NC) of 35.

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

d.⁹⁰ Teleconference rooms: maximum noise criteria (NC) of 20.

Part 3: Mechanical Equipment Sound Levels in Sensitive Rooms

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, based on the peak Leq.

Part 4: Best-Practice HVAC Installation

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.

Part 5: HVAC Sound Ratings

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 m_/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.

Nervous

Endocrine

Cardiovascular

	Core & Shell	Tenant Improvement	New Construction
Part 1: Acoustic Planning	-	P	P
Part 1: Ceilings	-	O	O
Part 2: Mechanical Equipment Sound Levels	O	P	P
Part 3: Mechanical Equipment Sound Levels in Sensitive Rooms	-	-	-
Part 4: Best-Practice HVAC Installation	-	-	-
Part 5: HVAC Sound Ratings	-	-	-

	Commercial Kitchen	Schools	Multifamily Residential	Restaurant	Retail
Part 1: Acoustic Planning	P	P	-	P	P
Part 1: Ceilings	-	-	-	-	-
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	-	-

Verification Methods Matrix

	Letters of Assurance	On-Site Checks
PART 1 (Design) Ceilings	Architect
PART 1 (Protocol) Acoustic Planning	Architect
PART 2 (Performance) Mechanical Equipment Sound Levels		Performance Test
PART 3 (Performance) Mechanical Equipment Sound Levels in Sensitive Rooms		Auditor Inspection
PART 4 (Design) Best-Practice HVAC Installation	Contractor	Spot Check
PART 5 (Design) HVAC Sound Ratings	MEP

Show 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.b	The General Services Administration's Sound Matters recommends a background noise maximum of NC 35 for private offices.
75.2.d	The General Services Administration's Sound Matters recommends a background noise maximum of NC 20 for teleconference facilities.

**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.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.
75.4.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.
75.5.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.
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.

**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.

This is a legacy version of the WELL Building Standard. Please check the latest version here.

75. Internally generated noise