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  1. Air
  2. Direct source ventilation

Direct source ventilation

Features>Air>17. Direct source ventilation

17. Direct source ventilation

Intent: 

To preserve air quality in occupied spaces through the isolation and proper ventilation of indoor pollution sources and chemical storage areas.

Air pollution can be created from a number of indoor sources, including cleaning products, office equipment and humid environments. Chemical storage closets can be a source of harmful vapors, including VOCs that are linked to cancer, organ and central nervous system damage. Copy rooms can contribute to the production of ozone, which is linked to asthma and other respiratory diseases. Bathrooms can be a source of mold and mildew that release spores and toxins, which can trigger asthma and allergies in susceptible individuals.

Part 1: Pollution Isolation and Exhaust

All cleaning and chemical storage units, all bathrooms, and all rooms that contain printers and copiers (except those meeting the low-emission criteria of Ecologo CCD 035, Blue Angel RAL-UZ 171, or Green Star) meet the following conditions:

a. Are closed from adjacent spaces with self-closing doors.
b.1 Air is exhausted so that all air is expelled rather than recirculated.
Part 2: Exhaust Hood Design Guidelines

The following requirements are met:

a.105 Canopy hoods have side or partial panels, when allowable by code.
b.156 Type II hood overhangs and setbacks comply with ASHRAE 154-2011 (Table 3 - Minimum Overhang Requirements for Type II Hoods) on all open sides, measured in the horizontal plane from the inside edge of the hood to the edge of the top horizontal surface of the appliance.
c.156 The vertical distance between the front lower lip of the hood and cooking surface is less than or equal to 1.2 m [4 ft].
Part 3: Makeup Air System Design

The following requirements are met:

a.105 Makeup air velocity near (or directed at) the hood is less than 0.25 m/s [75 fpm].
b.168 Replacement air introduced directly into the exhaust hood cavity does not exceed 10% of the hood exhaust airflow rate.
c.157 At least 50% of the air that replaces the exhaust air is conditioned transfer air rather than make up air.
Part 4: Appliance Guidelines

The following requirements are met:

a.156 Appliances are grouped under exhaust hoods according to effluent productions and associated ventilation requirements, as specified in ASHRAE Standard 154-2011 per hood type (defined by the classifications used in ASHRAE Standard 154-2011 for light, medium, heavy and extra-heavy appliance duty levels).
b.158 Appliances have a rear seal between the appliance and the wall, when allowable by code.
c.156 Appliances located at the end of a cook line requiring exhaust airflow rates greater than 460 L/s/m [300 cfm/ft], have a full side panel or an end wall.
Part 5: Locker Rooms

Locker rooms, if present, must be ventilated in the following manner:

a.132 The return air is vented outdoors and not recirculated.
b.132 The ventilation rate is at least 1.33 Air Changes per Hour (ACH).
Immune
Respiratory

Applicability Matrix

Core & Shell New & Existing Buildings New & Existing Interiors
Part 1: Pollution Isolation and Exhaust O O O
Commercial Kitchen Education Multifamily Residential Restaurant Retail
Part 1: Pollution Isolation and Exhaust O O - O O
Part 2: Exhaust Hood Design Guidelines O - - - -
Part 3: Makeup Air System Design O - - - -
Part 4: Appliance Guidelines O - - - -
Part 5: Locker Rooms - O - - -

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
Part 1: Pollution Isolation and Exhaust Mechanical and Architectural Drawings
Part 2: Exhaust Hood Design Guidelines MEP Spot Check
Part 3: Makeup Air System Design
Part 4: Appliance Guidelines MEP Spot Check
Part 5: Locker Rooms Mechanical Drawing

1

U.S. Green Building Council. LEED v4: Reference Guide for Building Design and Construction. Washington D.C.: U.S. Green Building Council; 2013: 37, 43-44, 541-552, 567, 605, 623, 645-53, 658-61, 682-3, 685-6, 723-4.
17.1.b

USGBC's LEED v4 EQ Credit: Enhanced Indoor Air Quality Strategies requires no recirculation of air in spaces where hazardous gases or chemicals may be present or used (e.g., garages, housekeeping and laundry areas, and copying and printing rooms).
105

California Energy Commission. Design Guide: Improving Commercial Kitchen Ventilation System Performance. http://www.energy.ca.gov/reports/2003-06-13_500-03-034F.PDF. Revised May 5, 2003. Accessed October 29, 2014.
17.2.a

The California Energy Commission's Design Guide suggests installing side and/or back panels on canopy hoods.
17.3.a

The California Energy Commission P500-03-034F provides design suggestions for commercial kitchen ventilation systems, including minimizing the makeup air velocity near the hood, noting that the velocity should be less than 75 fpm.
132

Wenger Corporation. Planning your athletic facility. http://www.wengercorp.com/Construct/docs/Athletic%20Planning%20Guide%20b.... Published 2011. Accessed March 25, 2015.
17.5.a

The guide notes that air from locker rooms should not be re-circulated.
17.5.b

The guide notes that the HVAC system should exchange air once about every 45 minutes, which is equivalent to 1.33 air changes per hour.
156

American National Standards Institute & American Society of Heating, Refrigerating and Air-Conditioning Engineers. 2015 Minnesota Mechanical and Fuel Gas Code with ANSI/ASHRARE Standard 154-2011. http://codes.iccsafe.org/app/book/content/2015_Minnesota/Mechanical/ASHR.... Published 2014. Accessed March 25, 2015.
17.2.c

ANSI/ASHRAE 154-2011 specifies that "the vertical distance between the front lower lip of the hood and appliance cooking surface shall not exceed 4 ft".
17.2.b

ANSI/ASHRAE 154-2011 states that type II hood overhangs "shall comply with Table 3 on all open sides, measured in the horizontal plane from the inside edge of the hood to the edge of the top horizontal surface of the appliance."
17.4.c

ANSI/ASHRAE Standard 154-2011 defines cooking processes that require exhaust airflow rates of 300 cfm/ft or greater as either "heavy" or "extra-heavy" cooking.
17.4.a

The ANSI/ASHRAE Standard 154-2011 provides appliance duty levels for light, medium, heavy, and extra-heavy appliance duty levels based on required exhaust airflow rates for cooking processes.
157

American National Standards Institute, American Society of Heating, Refrigerating and Air-Conditioning Engineers, U.S. Green Building Council & Illuminating Engineering Society. 2013 Supplement to Standard 189.1-2011 - Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings. https://www.ashrae.org/File%20Library/docLib/StdsAddenda/189_1_2011_2013.... Published 2013. Accessed March 25, 2015.
17.3.c

The 2013 Supplement to Standard 189.1-2011 notes that "at least 50% of all replacement air must be transfer air that would otherwise be exhausted."
158

Swierczyna, R, Sobiski, P, Fisher, D, Vaughn, M, and Cole, T. Supplemental Research to ASHRAE 1202-RP: Effects of Range Top Diversity, Range Accessories, and Hood Dimensions on Commercial Kitchen Hood Performance. http://www.fishnick.com/publications/ventilation/Ashrae1202SupPgeReport.pdf. Published January 2006. Accessed March 25, 2015.
17.4.b

The supplemental research document to ASHRAE 1202-RP notes that "adding a rear appliance seal reduced the exhaust rate to 2700 cfm."
168

ANSI/ASHRAE/IES Standard 90.1-2010: Energy Standard for Buildings Except Low-Rise Residential Buildings. Atlanta: ASHRAE; 2010.
17.3.b

ANSI/ASHRAE/IES Standard 90.1-2010 section 6.5.7.1.1 states that "replacement air introduced directly into the hood cavity of kitchen exhaust hoods shall not exceed 10% of the hood exhaust airflow rate."
Features>Air>17. Direct source ventilation