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LEED v2009
New Construction
Indoor Environmental Quality
Construction IAQ Management Plan—Before Occupancy

LEED CREDIT

NC-2009 IEQc3.2: Construction IAQ management plan - before occupancy 1 point

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Dylan Connelly

Integral Group
Mechanical Engineer

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Requirements

Develop an (IAQ) management plan and implement it after all finishes have been installed and the building has been completely cleaned before occupancy.

Option 1. Flush-out1
Path 1
After construction ends, prior to occupancy and with all interior finishes installed, install new filtration media and perform a building flush-out by supplying a total air volume of 14,000 cubic feet of outdoor air per square foot (4,500 cubic meters of outdoor air per square meter) of floor area while maintaining an internal temperature of at least 60° F (15° C) and relative humidity no higher than 60%.

OR

Path 2
If occupancy is desired prior to completion of the flush-out, the space may be occupied following delivery of a minimum of 3,500 cubic feet of outdoor air per square foot (1,000 cubic meters of outdoor air per square meter) of floor area. Once the space is occupied, it must be ventilated at a minimum rate of 0.30 cubic feet per minute (cfm) per square foot (0.1 cubic meters per minute per square meter) of outside air or the design minimum outside air rate determined in IEQ Prerequisite 1: Minimum Indoor Air Quality Performance, whichever is greater. During each day of the flush-out period, ventilation must begin a minimum of 3 hours prior to occupancy and continue during occupancy. These conditions must be maintained until a total of 14,000 cubic feet per square foot (4,500 cubic meters per square meter) of outside air has been delivered to the space.

OR

Option 2. Air testing
Conduct baseline IAQ testing, after construction ends and and prior to occupancy using testing protocols consistent with the EPA Compendium of Methods for the Determination of Air Pollutants in Indoor Air or as the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO. Demonstrate that the contaminant maximum concentrations listed below are not exceeded:

Contaminant

Maximum Concentration

EPA Compendium method

ISO method

Formaldehyde

27 parts per billion

IP-6

ISO 16000-3

Particulates (PM10)

50 micrograms per cubic meter

IP-10

ISO 7708

Total volatile organic compounds (TVOCs)

500 micrograms per cubic meter

IP-1

ISO 16000-6

4-Phenylcyclohexene (4-PCH) *

6.5 micrograms per cubic meter

IP-1

ISO 16000-6

Carbon monoxide (CO)

9 parts per million and no greater than
2 parts per million above outdoor levels

IP-3

ISO 4224

*This test is required only if carpets and fabrics with styrene butadiene rubber (SBR) latex backing are installed as part of the base building systems.

For each sampling point where the maximum concentration limits are exceeded, conduct an additional flush-out with outside air and retest the noncompliant concentrations. Repeat until all requirements are met. When retesting noncompliant building areas, take samples from the same locations as in the first test, although it is not required. Conduct the air sample testing as follows:
  • All measurements must be conducted prior to occupancy, but during normal occupied hours with the building ventilation system started at the normal daily start time and operated at the minimum outside air flow rate for the occupied mode throughout the test.
  • All interior finishes must be installed, including but not limited to millwork, doors, paint, carpet and acoustic tiles. Movable furnishings such as workstations and partitions should be in place for the testing, although it is not required.
  • The number of sampling locations will depend on the size of the building and number of ventilation systems. The number of sampling locations must include the entire building and all representative situations. Include areas with the least ventilation and greatest presumed source strength.
  • Air samples must be collected between 3 and 6 feet from the floor to represent the breathing zone of occupants, and over a minimum 4-hour period.
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Frequently asked questions

Should we install furniture and furnishings before IAQ testing or flushout?

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The air temperature and/or relative humidity went out of the credit requirement specifications for a portion of the flush-out. What do we do? Can we extend the flush-out for the equivalent amount of time to make up for it?

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Addenda

5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add in after "...at normal daily start times and at the minimum outside airflow rate.", "For projects with standardized identical construction, such as classrooms in a school or multifamily residential units, identify which rooms are identical in construction, finishes, configuration, square footage, and HVAC systems. For these scenarios, project teams can sample the identical spaces by testing one in seven."
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add "and the ISO methods" after "The protocols described in the referenced publication, EPA\'s Compendium of Methods for the Determination of Air Pollutants in Indoor Air,"
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add in after "...the greatest presumed contaminant source strength", "Determine the number of ventilation systems serving the building. Then, determine if the individual floor plates served by each single ventilation system are larger or smaller than 25,000 square feet. If they are smaller, take at least one sample for every 25,000 square feet, or fraction thereof, served by a single ventilation system. If they are larger, take one sample per floor plate. For example, a 110,000 square foot building with ten 11,000 square foot floors, served by a single ventilation system, needs only five samples - one per 25,000 square feet (or fraction thereof) because each 11,000 foot floor plate is smaller than 25,000 square feet. However, a building with ten 30,000 square foot floors, also served by a single ventilation system, needs ten samples for the building because each 30,000 floor plate is larger than the 25,000 sq ft criterion." Delete, "For example" in the following sentence.
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 2/14/2015
Rating System Correction
Description of change:
(1) In the first sentence of the paragraph, replace the text "and as additionally detailed in the LEED Reference Guide for Green Building Design and Construction, 2009 Edition" with "or the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO"(2) In the table, insert two columns to the right (refer to supplementary guidance)(3) In the third bullet item, replace the second sentence (begins with "For each portion") with "The number of sampling locations must include the entire building and all representative situations."
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
(1) In the first sentence of the paragraph, replace the text "and as additionally detailed in the LEED Reference Guide for Green Building Design and Construction, 2009 Edition" with "or the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO"(2) In the table, insert two columns to the right (refer to supplementary guidance)(3) In the third bullet item, replace the second sentence (begins with "For each portion") with "The number of sampling locations must include the entire building and all representative situations."
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for occupied spaces, "Occupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space."
Campus Applicable
No
Internationally Applicable:
No
11/2/2009Updated: 2/14/2015
Reference Guide Correction
Description of change:
To the left side of graph, remove a zero from the number "60000" so it becomes "6000"
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for nonoccupied spaces, "Nonoccupied spaces are defined as spaces designed for equipment and machinery or storage with no human occupancy except for maintenance, repairs, and equipment retrieval."
Campus Applicable
No
Internationally Applicable:
No
10/1/2012Updated: 2/14/2015
Reference Guide Correction
Description of change:
In the second paragraph, add in "optionally" before "including furniture and furnishings" so the sentence reads, "After construction and installation of all finishes (optionally including furniture and furnishings)."
Campus Applicable
No
Internationally Applicable:
No
8/1/2011
LEED Interpretation
Inquiry:

Overview: This CIR applies to Option 2- Air Quality Testing. With regards to the process to demonstrate that the maximum TVOC concentrations are below 500 micrograms/cubic meter, this CIR is requesting the acceptance of an alternate unit of measure based on a volumetric reading from an instantaneous, direct reading photoionization detector instrument (PID) using a 10.6 eVolt lamp. This reading would be recorded in a ppb (parts per billion) measurement and then converted to the designated unit of measure called out in the requirements (micrograms/cubic meter) using a conversion factor. This direct reading approach for TVOC will offer a more economical solution for IAQ testing by a factor of approximately two for our ~480,000 SF project. Methodology A conversion factor has been developed (by EH&E in Newton, MA) and is based on a TVOC "fingerprint" of 33 individual volatile organic compounds grouped by chemical category, resulting from a technical evaluation of the Building Assessment Survey Evaluation (BASE) data, the EPA TO-15 list of VOC\'s, and other relevant technical data. The EH&E team examined three lists of indoor VOC\'s to develop the TVOC "fingerprint." These lists originated the following sources: BASE dataset for commercial buildings, PID-readable chemical compounds, and an EPA approved list of indoor VOC\'s. Seven individual VOC\'s from the BASE data the had the highest reported concentrations and could be measured by a PID formed an initial, preliminary fingerprint. These individual VOC\'s were chemically regrouped (i.e. alcohols, halogenated hydrocarbon, aliphatics, etc.) and the relative group proportions in the fingerprint were compared with the BASE dataset. Based on the EPA guidance and a review of indoor VOC literature, additional VOC\'s not measured in the BASE dataset were considered for inclusion. By mapping additional pollutants from the EPA TO-15 list of VOC\'s, EH&E modified the fingerprint to represent new or existing buildings. The expanded list of compounds included all BASE compounds that were both on the EPA TO-15 list and measurable by the PID. This "fingerprint" is based on the following list of chemicals, sorted by their group, their average group molecular weight (AGMV), the % in BASE data, and specific compounds in fingerprint: Format given in following order: Group/AGMW/% in BASE/Compounds in Fingerprint Aldehydes/44.06/12%/Acetaldehyde Alkanes & alkenes/113.6/8%/n-undecane; n-decane; Nonane; Octane; n-hexane; 1,3 butadiene Aromatics/110.5/14%/d-limonene; a-pinene; Naphthalene; o-xylene; m- & p-xylenes; Ethylbenzene; Styrene; Toluene; Benzene Halogenated Hydrocarbons/130/15%/1,2 -dbromoethane; 1,2, 4-trichlorobenzene; 1, 2, -dichlorobenzene; Trichlorobenzene; 1,3,5 -trimethylbenzene; Chlorobenzene; 1,1 -dichloroethene; Vinyl chloride Alcohols/78.5/31%/2 -butoxyethanol; Phenol; 1 -butanol Ketones/58.1/15%/Acetone Other(e.g. acetates,sulfides, ethers, etc.)/92.55/5%/Butyl acetate; Dimethyl disulfide; Ethyl acetate; Carbon disulfide; t-butyl methyl ether Conversion Factor In order to convert a PID reading from part per billion (ppb) to a mass-based equivalent in micrograms/cubic meter, the PID value is multiplied by a derived conversion factor, MCF, defined below as the product of two correction factors, CF-1 and CF-2. For the TVOC fingerprint listed above, the formula is MCF = CF1 * CF2, where MCF = 2.70 Mass Conversion Factor CF1 = 0.88 Correction for predicted ppb PID reading to "actual" ppb reading, based on isobutylene equivalents, and CF2 = 3.07 Correction for "actual" ppb to micrograms/cubic meter equivalent, based on the chemical distribution of the mixture and the average molecular weight. Summary The acceptance of this CIR would provide a lower cost test for TVOCs, including the use of both hand held PID-TVOC direct read instruments and permanently installed PID-TVOC direct read instruments.

Ruling:

**Update January 1, 2014: This Interpretation is no longer valid. See LI 2467.
**Update October 1, 2013
The applicant is requesting approval for use of a photoionization detector instrument (PID) to measure TVOC concentrations during air quality testing. The proposed alternative for testing of TVOC using a PID is not an approved method in the United States Environmental Protection Agency Compendium of Methods for the Determination of Air Pollutants in Indoor Air which are the methods required for this credit. The IAQ testing must be conducted according to the test procedure outlined in the referenced standard using an approved indoor TVOC measurement device, which is either Method IP-1A, Stainless Steel Canister, or IP-1B, Solid Adsorbent Tubes. Both of these methods utilize GC/MS analyses to determine the concentrations of the collected VOC\'s. Most laboratories will calculate the total concentration of VOC\'s (TVOC) according to a toluene equivalent mass from the Total Ion Chromatogram (not just the peaks of EPA TO-15 compounds, but the integrated area of the peaks from all compounds). This method is discussed in the California Department of Health Services (CDHS) Standard Practice. http://www.ciwmb.ca.gov/greenbuilding/Specs/Section01350 First of all PID analyses miss many of the common indoor VOC\'s such as aldehydes and aliphatics and has a poor response factor (i.e. and thus large uncertainty) for common indoor VOC\'s such as alcohols. The "fingerprint" method proposed for calibration of the PID is fundamentally flawed in that it uses a calibration based upon an assumed fixed percentage of mass of VOC\'s from seven different groups of VOC\'s while the actual mass percentage of VOC\'s can vary widely from building to building. The errors associated with the "fingerprint" method could be easily demonstrated by simultaneously measuring the TVOC concentration with a PID and either method IP-1A or IP-1B in a number of buildings. Such a comparison was conspicuously missing from the EH&E report "Development of a Method to Convert Total Volatile Organic Compound Measurements in Buildings to Equivalent Mass Based Units", although the report did contain numerous caveats regarding the accuracy of the "fingerprint method" including limitations related to the "Representativeness of TVOC List" and the "Variability by Building Type". Additionally, the LEED-NC v2.2 Reference Guide states that samples must be collected over a minimum 4-hour period; instantaneous TVOC measurements do not satisfy this requirement.Applicable internationally.

Campus Applicable
No
Internationally Applicable:
Yes
5/30/2007
LEED Interpretation
Inquiry:

We have a ~100,000 square foot 3-pointed T-shaped building with five floors. On the first floor there is an additional 7,800 sq. ft single story extension that will be used for a cafeteria and kitchen. The other sections are approximately 5,500 sq. ft. on each of floors 1 - 5 for a total of approximately 16,500 sq. ft. per floor. Each section is attached to a core and has similar furnishings and usage including both open and private offices and conference/training rooms with the following exceptions: the first floor includes an entrance lobby and the second floor includes a movable filing area and a server room. The HVAC system utilizes variable air volume boxes with induction fans. Separate air handling units (AHUs) in each section on each floor serve the three main vertical sections. There is one outdoor air fan on the roof above each section (3 total) which supply outside air down to the respective sections\' five AHUs. There are an additional nine ceiling-mounted AHUs for the cafeteria and one unit for the kitchen. These ten units are supplied with outside air through one rooftop intake fan that is ducted to each unit. In summary, there are fifteen main AHUs, nine cafeteria AHUs, and one kitchen AHU (25 total). If one were to interpret a "separate ventilation system" as each individual AHU, this would infer 25 sampling locations, which is pointlessly excessive and costly for a 100,000 square foot building. It risks returning to the days when no IAQ testing was done because there was no cost effective protocol in the LEED credit system. We see no technical reason why the criterion should be based on individual AHUs. Identical AHUs used to serve multiple zones all deliver the same volume of outside air per person per ASHRAE requirements for the respective space use. The volume of outside air in supply air varies with time, not by zone i.e. with variations in outside air temperature. The point sources of indoor air pollutants in and around the building and its mechanical system, and their treatment, will be independent of the number of air handling units used to serve the building. If a building designer uses one four-ton AHU vs. four identical one-ton AHUs, what will sampling in four locations achieve? Due to the unique T-shaped design, the building core breaks what would have been contiguous floors into separate areas. While these areas are not physically contiguous, they have similar furnishings and space usages, which present similar indoor pollutants. In order to re-establish an economically and logistically sound method for wide use across multiple building formats, we have selected this project to seek clarification on the following terms: 1) "separate ventilation system" in a building with numerous AHUs and 2) "contiguous floor area" in unusually shaped buildings. We propose that for each portion of the building served by a separate ventilation system, the number of sampling points must not be less than one per 25,000 square feet, or for each contiguous floor area, whichever is larger, with the following clarifications: 1) Allow contiguous floor area to be defined as areas with similar furnishings and space usage, even if the space crosses a building core (but not up or down a floor). 2) Require at least one sample in each building use location, i.e.. cafeteria vs. office vs. warehouse (server rooms are not included since they are not regularly occupied). 3) Allow "separate ventilation system" to be defined as fundamentally different HVAC designs, i.e.. heat pumps vs. built-up units vs. TDV (underfloor) vs. overhead mixing. Following the above protocol, we propose to sample six locations in this building: 1st Floor Cafeteria 1st Floor Lobby 2nd Floor Filing Area 3rd Floor Private Office 4th Floor Training Room 5th Floor Open Office (A "separate ventilation system" could be interpreted as AHUs served by a common outside air source. This would require excessive sampling in buildings equipped with small rooftop package units and thus is not practical.)

Ruling:

Per the LEED-NCv2.2 requirements, the number of sampling sites would be one per each of the separate ventilation systems. The NCv2.2. requirement for one sampling location in "each portion of a building served by a separate ventilation system" is based upon the fact that the ventilation systems define a distinct mixed volume of indoor air as tested under the required minimum outside air percentage mode. Since there may be expected to be variations in the indoor air concentrations in this mixed zone, there is a further requirement that the area in the zone with the least ventilation and greatest presumed contaminant source strength be tested. The contaminants in this mixed volume of air are determined by the emissions from the materials in the air space and the amount of outside air being delivered to the air space. As both the materials and the outside air delivery rates in different ventilation system zones can vary, separate air contaminant measurements are required for each ventilation system zone. If the delivery of outside air on an air change per hour basis and the materials in a ventilation zone are identical (e.g. a specific type of hotel room, or apartment/condominium with separate ventilation systems) a HERS random sampling plan may be employed (i.e. random 1 in 7 selection from each model of room). In addition, for buildings with large numbers of identical rooms each with separate ventilation systems, a minimum of 3 rooms for a particular model of room shall be deemed sufficient. If one or more of the three measurements made per model room fail than an additional three of that type guest room be tested. All failed rooms will be re-tested following flushing with outside air. In this specific case, if the cafeteria space is one undivided open space with identical (not just similar) materials throughout the space and the delivery of outside air on an air change per hour basis is identical for each system, then a HERS random air sampling of 1 in 7 of the 9 ventilation system zones is acceptable. Thus, 2 test locations are required for the cafeteria space (i.e. randomly select 2 of the 9 ventilation system zones) and these locations shall include the area with the least ventilation and greatest presumed contaminant source strength in each zone. The kitchen, which is both a separate space with a separate ventilation system and different materials requires a second test location. Again, to include the area with the least ventilation and greatest presumed contaminant source strength is acceptable. The five floors of the main building with three separate ventilation systems that serve separate spaces with different materials requires one sampling location per ventilation system, again to include the area with the least ventilation and greatest presumed contaminant source strength is acceptable. Thus, a total of 18 test locations are required, two in the cafeteria, one in the kitchen and 15 in the main building.

Campus Applicable
No
Internationally Applicable:
No
10/8/2008
LEED Interpretation
Inquiry:

The 9/5/2006 allows projects to provide both IAQ testing and building flush-out in different construction phases. We intend to provide IAQ testing and building flush-out in different areas of the building within the same construction phase. Our project is a high school addition/renovation that will be occupied in phases. The first phase of construction is complete and those spaces were tested, prior to occupancy, based on the credit ruling dated 10/8/2002. The second phase of the project includes a pool and academic spaces. We are concerned that the chemicals used in the pool will adversely impact the testing results. We therefore propose flushing out that space, using the \'purge mode\' on the pool\'s mechanical unit. Based on the 9/8/2004 credit ruling, we will achieve 14,000 cu ft of outdoor air per square foot of floor space in less than 5 days. As the rest of the Phase 2 areas will not meet the flush-out criteria prior to the scheduled occupancy, we therefore intend to provide IAQ testing in the remaining portions of the building. Until both the IAQ testing and the flush-out is complete, we will prevent cross-contamination between areas. Protection measures will follow the SMACNA Guidelines for Occupied Buildings as outlined in the Construction IAQ Management Plan. Please confirm if the proposed compliance path meets the credit intent. If it is not acceptable, please clarify what changes are required in order to meet the credit requirements.

Ruling:

The applicant is requesting clarification regarding the implementation of flush-out procedures and IAQ testing during the same construction phase. As described, the proposed approach appears to satisfy the credit intent. The indoor air quality problems from construction activity in each space are either reduced from a flush-out or confirmed to be minimal from IAQ testing. Please note, however, that IAQ testing procedures for LEED-NC v2.2 are outlined in the LEED-NC v2.2 Reference Guide and are not identical to the testing procedure outlined in the 10/8/2002 CIR (applicable to LEED-NC v2.1). The reference guide has more stringent maximum concentration requirements and additional testing procedure guidelines. Also note, the air contaminants from swimming pool chemicals, such as chlorine, will not affect the concentration levels tested for this credit. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
7/1/2012
LEED Interpretation
Inquiry:

The project is a training complex in Oklahoma. The new facilities consist of two new B/COF buildings. We intend to conduct baseline IAQ testing, as outlined in option 2. We would like clarification in determining the number of sampling locations within the buildings. The two B/COF buildings each have three floors and encompass approximately 93,000 square feet. For these two buildings, three Dedicated Outside Air Systems (DOAUs) distribute outside air throughout each B/COF building; however, separate Water Source Heat Pumps (WHPs) condition the outside air delivered to each room. Each B/COF building contains 150 residential barracks units which each have a separate WHP. In addition, each B/COF building has identical rooms whose HVAC needs are provided by identical WHP units (e.g., identical offices, identical lounges, and identical learning centers). Following the guidance provided by the LEED for New Construction Version 2009 Reference Guide, each B/COF building would require 184 sampling locations. We propose the following alternative compliance path for multi-family, residential projects with similar rooms and residential units: Per the guidance provided by LI 1740 dated 05/30/2007 , If the delivery of outside air on an air change per hour basis and the materials in a ventilation zone are identical (e.g. a specific type of hotel room, or apartment/condominium with separate ventilation systems) a HERS random sampling plan may be employed (i.e. random 1 in 7 selection from each model of room). In addition, for buildings with large numbers of identical rooms each with separate ventilation systems, a minimum of 3 rooms for a particular model of room shall be deemed sufficient. If one or more of the three measurements made per model room fail, then an additional three of that type guest room are tested. All failed rooms will be re-tested following flushing with outside air. Furthermore, per the guidance provided by LI 5209 dated 04/21/2009, an acceptable strategy for each individual unit type configuration, is a minimum of 3 samples are taken for each identical unit type. (Note: In this case, the minimum of 3 samples refers to three Indoor Air Quality (IAQ) sampling locations for each similar unit type.) Implementing the minimum of three (3) rooms for a particular model of room, we estimate that a total of twenty-seven (27) sample sets will be required in each B/COF building. Per this methodology, identical Dwelling Units will be grouped together and a minimum of 3 sampling locations will be included in the Indoor Air Quality Testing. In the same manner, similar room types with identical ventilation units and rates (i.e. computer learning rooms) will form a separate group upon which a minimum 3 sampling locations will be included. As stated above, this methodology is based on the LI 1740 dated 5/30/2007 for LEED NCv2.2 and LI 5209 dated 04/21/2009. For this project, all Dwelling Units are identical. In each B/COF building, 6 WHP\'s serve 6 identical Dwelling Units and the corridors on the Northeast and Northwest corners of each floor. Although corridors are not considered occupied space per ASHRAE 62.1-2007, the delivery of outside air on an air change per hour basis and the materials in these ventilation zones differ from the remaining Dwelling Units. Per this methodology, these 6 Dwelling Units will be grouped together and 3 sampling locations will be included in the Indoor Air Quality Testing. The remaining 144 identical Dwelling Units are served by separate identical WHP\'s and 3 sampling locations will be included. The remaining groups are served by identical WHP\'s per group, and thus will include 3 samples each for the identical Drill Instructor Rooms (1 per floor), identical Laundry/Vending Rooms (1 per floor), identical Day Rooms (1 per floor), and identical Computer Learning Rooms (1 per floor) for a total of 12 sampling locations. For zones without identical rooms each served with separate ventilation systems, the original guidance will be followed, and the number of sampling locations for each separate ventilation system will not be less than 1 per 25,000 square feet or for each contiguous floor area, whichever is larger. Thus, an additional 9 sampling locations will be included. Please confirm if this alternative compliance path meets the credit intent. If this is not acceptable, please clarify how the IAQ testing option may be applied to projects with identical residential units or rooms that have separate ventilation units but equal ventilation rates based on air changes per hour and identical materials within each unit or room.

Ruling:

The project is inquiring if the proposed sampling for two barrack buildings, each with 150 residential barrack units, offices, lounges, and learning centers satisfies IEQc3.2, Construction IAQ Plan Before Occupancy. As stated in LEED Interpretation 1740, a sampling approach according to HERS guidelines of one in seven of identical spaces is acceptable. Therefore each sample group would consist of identical spaces, one out of every seven of which are to be tested. The LEED Interpretation also allows for a minimum of 3 tests in each sample group, if there are more than 21 identical spaces in a sample group. For example, one sample group might have 1 unit/space in it and another might have 50 identical unit/spaces in it. You would test one in the first sample group, and a minimum of three in the second sample group. Without more information on the number of identical spaces in each sample group, it is unclear if the proposed option completely satisfies the requirements. Note that HERS has specific guidelines in case of test failures in order to continue with a sampling approach. The sampling plan developed for the project, must observe HERS guidelines on what to do in the event of a test failure.

Campus Applicable
No
Internationally Applicable:
No
3/8/2004
LEED Interpretation
Inquiry:

This question concerns allowable contactor activities before, during, and after the required two week flushout period. Your response of 10/17/2001 on this credit seems to imply the following sequence of events: 1. Complete punch list 2. Perform flushout 3. Install furniture The implied reason for this is that the furniture will become a "sink" for indoor pollutants, if installed before the flushout. In our project, the contractor\'s work includes furniture installation. Furthermore, they expect to do touch up painting after move-in, since the movers are likely to cause some damage to building finishes. Following the logic of the 10/17/01 decision, this would be prohibited, as the touch up painting would have to be performed before the flushout, but the furniture move-in, which created the need for touch up, could not be allowed until after flushout. On the other hand, it could be argued that the furniture should be moved in before flushout, to give the furniture an opportunity to "off gas". Is the time of furniture move-in critical, relative to the flushout period? If so, when should it occur? Can any activities, such as touch up painting, be performed after the flushout?

Ruling:

The sequence of final construction activities will naturally vary between contractors and depend on the contractor\'s scope of work. It is most critical that the flush-out be conducted AFTER substantial completion of construction (including major IEQ-relevant punch list items) and prior to occupancy. As stated in the EQc3.2 ruling dated 10/17/2001, it is recommended that the flush-out occur prior to furniture installation (with the exception of non-porous items). Touch-up painting resulting from furniture move-in should not be a significant source of indoor air contamination in comparison to the VOC and particulate emissions from the building materials and construction process and need not be completed prior to flush-out. Applicable internationally.UPDATE 10/1/12: Now applicable to 2009 versions of the rating system and not applicable to older versions.

Campus Applicable
No
Internationally Applicable:
Yes
2/23/2006
LEED Interpretation
Inquiry:

This project is a 147,000 call center. The owner procures air quality testing services on all their new and existing buildings and have done so before they ever did any LEED projects. They recognize the value of superior air quality in terms on worker productivity and avoidance of risk. On this new project the contractor was very diligent in ensuring that low VOC paints, adhesives and sealants were used. No wood materials with added Urea formaldehyde were allowed on the project. The contractor collected MSDS sheets on all these materials. All the carpet meets the CRI Green Label Plus certification. The contractor developed and implemented a Construction Indoor Air Quality Management Plan which followed the SMACNA guidelines for buildings under construction. (The project will not achieve the LEED credit EQc3.1 because there was no MERV 13 filtration provided) In order to ensure superior indoor air quality at the new facility the team is employing air quality testing. Along with testing for the elements required for this credit the team will also test for mold. The testing team is utilizing the EPA Protocol for Environmental Requirements, Baseline IAQ and Materials, for the Research Triangle Park Campus, Section 01445 as required per the LEED Reference Guide credit EQ3.2. The team also referred to the guidelines in the LEED CI Reference Guide credit EQ3.2 for air testing in occupied buildings. The testing began before the building was occupied and the tests for Formaldehyde and total VOC\'s appeared to be within the required levels although all results are not yet in. The testing for particulate level was quite high. The cause of the high particulate appears to be dust in the underfloor area and mechanical rooms. Since the initial testing the building has been about 25% occupied. The underfloor areas and mechanical rooms have been cleaned again. The building ventilation system will provide minimum ventilation rate 3 hours prior to daily occupancy and continue while the space is occupied. The rate of outside air will be at least .30 cfm / sq ft. If levels are exceeded the space will be flushed out by increasing the rate of outdoor air during unoccupied hours. Any additional adjustments to the mechanical system will addressed if needed. Additional testing will be done until all the required test samples meet the concentration levels. Can this method be used to meet the requirements to achieve credit EQc3.2?

Ruling:

You are essentially asking if it is acceptable to continue the IAQ testing and contaminant mitigation activity while the building is partially occupied. The owner\'s actions are commendable, but unfortunately your proposal is not acceptable. The referenced EPA standard states that flush-out, retesting, and compliance with contaminant limits must all be completed before occupancy, and the Technical Advisory Group has chosen not to diverge from it. Instead, the TAG recommends that you examine your occupancy and ventilation schedules to see if you conformed to the flush-out schedule described in EQc3.2 ruling dated 9/8/04. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
3/24/2009
LEED Interpretation
Inquiry:

Overview: This CIR applies to Option 2- Air Quality Testing. With regards to the process to demonstrate that the maximum TVOC concentrations are below 500 micrograms/cubic meter, this CIR is requesting the acceptance of an alternate unit of measure based on a volumetric reading from an instantaneous, direct reading photoionization detector instrument (PID) using a 10.6 eVolt lamp. This reading would be recorded in a ppb (parts per billion) measurement and then converted to the designated unit of measure called out in the requirements (micrograms/cubic meter) using a conversion factor. This direct reading approach for TVOC will offer a more economical solution for IAQ testing by a factor of approximately two for our ~480,000 SF project. Methodology A conversion factor has been developed (by EH&E in Newton, MA) and is based on a TVOC "fingerprint" of 33 individual volatile organic compounds grouped by chemical category, resulting from a technical evaluation of the Building Assessment Survey Evaluation (BASE) data, the EPA TO-15 list of VOC\'s, and other relevant technical data. The EH&E team examined three lists of indoor VOC\'s to develop the TVOC "fingerprint." These lists originated the following sources: BASE dataset for commercial buildings, PID-readable chemical compounds, and an EPA approved list of indoor VOC\'s. Seven individual VOC\'s from the BASE data the had the highest reported concentrations and could be measured by a PID formed an initial, preliminary fingerprint. These individual VOC\'s were chemically regrouped (i.e. alcohols, halogenated hydrocarbon, aliphatics, etc.) and the relative group proportions in the fingerprint were compared with the BASE dataset. Based on the EPA guidance and a review of indoor VOC literature, additional VOC\'s not measured in the BASE dataset were considered for inclusion. By mapping additional pollutants from the EPA TO-15 list of VOC\'s, EH&E modified the fingerprint to represent new or existing buildings. The expanded list of compounds included all BASE compounds that were both on the EPA TO-15 list and measurable by the PID. This "fingerprint" is based on the following list of chemicals, sorted by their group, their average group molecular weight (AGMV), the % in BASE data, and specific compounds in fingerprint: Format given in following order: Group/AGMW/% in BASE/Compounds in Fingerprint Aldehydes/44.06/12%/Acetaldehyde Alkanes & alkenes/113.6/8%/n-undecane; n-decane; Nonane; Octane; n-hexane; 1,3 butadiene Aromatics/110.5/14%/d-limonene; a-pinene; Naphthalene; o-xylene; m- & p-xylenes; Ethylbenzene; Styrene; Toluene; Benzene Halogenated Hydrocarbons/130/15%/1,2 -dbromoethane; 1,2, 4-trichlorobenzene; 1, 2, -dichlorobenzene; Trichlorobenzene; 1,3,5 -trimethylbenzene; Chlorobenzene; 1,1 -dichloroethene; Vinyl chloride Alcohols/78.5/31%/2 -butoxyethanol; Phenol; 1 -butanol Ketones/58.1/15%/Acetone Other(e.g. acetates,sulfides, ethers, etc.)/92.55/5%/Butyl acetate; Dimethyl disulfide; Ethyl acetate; Carbon disulfide; t-butyl methyl ether Conversion Factor In order to convert a PID reading from part per billion (ppb) to a mass-based equivalent in micrograms/cubic meter, the PID value is multiplied by a derived conversion factor, MCF, defined below as the product of two correction factors, CF-1 and CF-2. For the TVOC fingerprint listed above, the formula is MCF = CF1 * CF2, where MCF = 2.70 Mass Conversion Factor CF1 = 0.88 Correction for predicted ppb PID reading to "actual" ppb reading, based on isobutylene equivalents, and CF2 = 3.07 Correction for "actual" ppb to micrograms/cubic meter equivalent, based on the chemical distribution of the mixture and the average molecular weight. Summary The acceptance of this CIR would provide a lower cost test for TVOCs, including the use of both hand held PID-TVOC direct read instruments and permanently installed PID-TVOC direct read instruments.

Ruling:

The applicant is requesting approval for use of a photoionization detector instrument (PID) to measure TVOC concentrations during air quality testing. The proposed alternative for testing of TVOC using a PID is not an approved method in the United States Environmental Protection Agency Compendium of Methods for the Determination of Air Pollutants in Indoor Air which are the methods required for this credit. The IAQ testing must be conducted according to the test procedure outlined in the referenced standard using an approved indoor TVOC measurement device, which is either Method IP-1A, Stainless Steel Canister, or IP-1B, Solid Adsorbent Tubes. Both of these methods utilize GC/MS analyses to determine the concentrations of the collected VOC\'s. Most laboratories will calculate the total concentration of VOC\'s (TVOC) according to a toluene equivalent mass from the Total Ion Chromatogram (not just the peaks of EPA TO-15 compounds, but the integrated area of the peaks from all compounds). This method is discussed in the California Department of Health Services (CDHS) Standard Practice. http://www.ciwmb.ca.gov/greenbuilding/Specs/Section01350 First of all PID analyses miss many of the common indoor VOC\'s such as aldehydes and aliphatics and has a poor response factor (i.e. and thus large uncertainty) for common indoor VOC\'s such as alcohols. The "fingerprint" method proposed for calibration of the PID is fundamentally flawed in that it uses a calibration based upon an assumed fixed percentage of mass of VOC\'s from seven different groups of VOC\'s while the actual mass percentage of VOC\'s can vary widely from building to building. The errors associated with the "fingerprint" method could be easily demonstrated by simultaneously measuring the TVOC concentration with a PID and either method IP-1A or IP-1B in a number of buildings. Such a comparison was conspicuously missing from the EH&E report "Development of a Method to Convert Total Volatile Organic Compound Measurements in Buildings to Equivalent Mass Based Units", although the report did contain numerous caveats regarding the accuracy of the "fingerprint method" including limitations related to the "Representativeness of TVOC List" and the "Variability by Building Type". Additionally, the LEED-NC v2.2 Reference Guide states that samples must be collected over a minimum 4-hour period; instantaneous TVOC measurements do not satisfy this requirement.

Campus Applicable
No
Internationally Applicable:
No
10/23/2006
LEED Interpretation
Inquiry:

BACKGROUND This credit interpretation request is specific to interpretation of EQ Credit #3.2 "Construction IAQ Management Plan: Before Occupancy " under version 2.1. The intent of this credit is "to prevent indoor air quality problems resulting from the construction process in order to help sustain the comfort and well-being of construction workers and building occupants". We believe the approach described below will achieve that intent. The Mazankowski Alberta Heart Institute Project is an expansion to the Walter C. MacKenzie Center, an existing active treatment hospital of approximately 2,000,000 square feet of occupied space. The Mazankowski Alberta Heart Institute will connect to the Walter C. MacKenzie Center through several corridors that will be isolated from the main building until the Heart Institute is occupied. The heart institute is a multi-storey building of approximately 350,00 Square Feet of occupied space consisting of 8 occupied floors each with an interstitial floor above to house building systems. The interstitial floors are completely separated from the occupied floors. The ventilation systems serving the building are configured such that central air systems provide 100% outdoor air to all occupied floors from the 2nd floor to the 8th floor. The main and lower levels are served from air systems that re-circulate a portion of the building air. Each occupied floor and each interstitial floor are separated into a minimum of 3 Fire compartments. Supply and exhaust air for each fire compartment can be isolated by closing smoke dampers in the supply and exhaust ductwork serving the respective fire compartment. The construction and occupancy schedule for the project requires that the building be occupied in stages. These stages would be at a minimum fire compartment by fire compartment and more likely floor by floor. REQUEST We are requesting that the USGBC interpret Credit 3.2 to allow "Before Occupancy" flushing to be conducted on a fire zone by fire zone basis for the Mazankowski Alberta Heart Institute. All unoccupied zones would be isolated from the occupied zones by closing the smoke dampers and taping off man doors serving unoccupied zones. The zones being flushed would utilize the main air systems to allow for the two-week building flush out period prescribed in the discussion for EQ Credit #3.2. The 2nd through 8th floors are served by air systems designed to provide 100% outdoor air. Therefore there will be no recirculation of the air from the occupied or flush-out spaces. For the lower and main floors served by a system that permits re-circulated air, these systems will be controlled so that 100% outdoor air is supplied through this system during the flush out period.

Ruling:

The CIR is inquiring if it is possible to conduct the two-week flush-out of a building in stages to allow for a staggered construction completion schedule. The inquiry indicates that the building floors and/or zones can be separated physically from adjacent spaces, to ensure no cross contamination from construction in the incomplete areas, while providing 100% outside air to accomplish the flush out. Previously posted CIR rulings, dated 10/17/2001 and 9/5/2006 approve the process for a staggered flush-out approach, provided that existing spaces are protected from construction-related contamination as well as prevention of cross-contamination between systems. Protection measures should follow the SMACNA Guidelines for Occupied Buildings and be outlined in the Construction IAQ Management Plan to ensure compliance.

Campus Applicable
No
Internationally Applicable:
No
12/1/2007
LEED Interpretation
Inquiry:

The project contains both systems furniture (42" application) for open areas, and modular wall systems (full height application that is demountable and reusable such as the DIRTT system). We are trying to schedule flush-out activities and understand from other CIRs that furniture installation may occur during or after flushout. Are modular walls as described here considered furniture?

Ruling:

Full height, demountable modular walls are essentially the same in form and function as permanent walls and as such are not considered furniture. They must be installed in the building prior to flush-out for the purposes of EQc3.2. Please note that such modular walls potentially affect other LEED credits (such as daylighting and views) and should therefore be included in any calculations and submissions required for those credits as well. Applicable Internationally.UPDATE October 1, 2012: This LEED Interpretation is not applicable to LEED-CI. Furniture must be installed before the flush-out for LEED-CI projects.

Campus Applicable
No
Internationally Applicable:
Yes
11/1/2011
LEED Interpretation
Inquiry:

The project is an 80,000 sf K-12 school located in the pacific northwest. A majority of the building is being conditioned by "standard" mechanical means and can demonstrate compliance according to ASHRAE 55-2004 Figure 5.2.1.1., however there are portions of the building that will be thermally regulated by natural ventilation and with extensive radiant systems.The purpose of this request is to determine whether the more passive, naturally ventilated portion of the building may be considered "naturally conditioned" with their thermal comfort criteria evaluated according to ASHRAE 55-2004 Figure 5.3 rather than being evaluated according to Figure 5.2.1.1.The northwest climate is considered heating dominated with narrow diurnal temperature variations and as a consequence has limited cooling needs, especially during the school year. The need for cooling is isolated to only brief time periods at the beginning and end of the 9-month school year when potential thermal comfort concerns would arise. To mitigate thermal comfort concerns during these isolated times, the design incorporates occupant-controlled operable windows and ceiling fans to allow comfort control within the classrooms. In addition to the operable windows, the design also includes utilizing the thermal massing properties of the concrete floors to better modulate the release of cooling within the space(s). The cooling will be supplied by evaporatively-cooled water via hydronic loops in the floors during the nighttime periods when the building is unoccupied. The intent is pre-charge the thermal mass of the floors with enough cooling to offset the effects of internal heat gains and eliminate the need for active mechanical cooling during the day. Since the charging is taking place during the evenings, there will not be any ability for the occupants to directly call for additional cooling to be added to floor or space and the mass will in essence be allowed to release it cooling naturally trough out the day. Lastly, we are interpreting that this approach of pre-cooling the mass without the need of compressor-based mechanical cooling could be construed as a assisted passive approach, however it is unclear whether the USGBC will recognize these spaces as "naturally conditioned" for the purposes of IEQc7.1. ASHRAE 55-2004, Section 5.3, states that "occupant-controlled naturally conditioned spaces are those spaces where the thermal conditions of the space are regulated primarily by the occupants through opening and closing of windows". We believe that the definition is still being satisfied with the mass pre-charging strategy described previously, since the regulation of the thermal conditions will still be controlled by the occupants through the opening and closing of windows.Can the thermal comfort criteria in these rooms be evaluated according to "naturally conditioned" rather than "typical" criteria and if so, is modeling an acceptable means of documenting compliance?

Ruling:

The applicant is asking whether a space that meets the ASHRAE Standard 55-2004 definition of "naturally conditioned spaces, occupant controlled," but is also served by an in-floor radiant cooling system that is in turn served by an evaporatively-cooled water tower that will be utilized at night to pre-charge the high thermal mass concrete floors, may be evaluated according to ASHRAE Standard 55-2004 Section 5.3 - Optional Method for Determining Acceptable Thermal Conditions in Naturally Conditioned Spaces in lieu of the requirements of Section 5.2 Method for Determining Acceptable Thermal Conditions in Occupied Spaces.Section 5.3 of Standard 55-2004 states, "there must be no mechanical cooling system for the space (e.g. refrigerated air cooling, radiant cooling, or desiccant cooling.)" in order to use the Optional Method for Determining Acceptable Thermal Conditions in Naturally Conditioned Spaces. If the radiant cooling system is operated during the day, the project would be considered mechanically cooled and not eligible to use the Section 5.3 method. However, if the system is operated as described in the Interpretation Request and the radiant cooling system is only used at night as a pre-cooling strategy then the intent and spirit of the conditions for using Section 5.3 are met. Note that:1. For times when active mechanical cooling OR heating is used during occupied hours, Section 5.3 does not apply and Section 5.2 Method for Determining Acceptable Thermal Conditions in Occupied Spaces shall be used.2. In the Cooling season when the night-time pre-cooling strategy is used, the minimum design operative temperatures in the morning shall be evaluated compared to the allowable minimum operative temperature based on Section 5.3 to ensure comfortable conditions throughout the day. Applicable internationally.

Campus Applicable
No
Internationally Applicable:
Yes
4/21/2009
LEED Interpretation
Inquiry:

We are requesting clarification on the number and location of IAQ testing measurements for a 140,000 SF university residence hall project. Based on guidance from previous CIRs for other buildings with large numbers of like spaces, we propose the IAQ testing approach described below: Corridors: The corridors are uninterrupted on each floor and are served by seven 100% outside-air Roof Top Units spaced along the building. Each RTU serves the corridor segments of the floors beneath it. (RTU 1 serves the West section of the corridors on floors 1-5, etc.) The corridors on each floor are identical in terms of materials, finish, usage and, for the most part, configuration. We propose to sample one location for each corridor RTU, with at least one test per floor. Any unique configurations will also be tested. (7 tests) Nonresidential spaces: Two additional RTUs serve several first floor common spaces: RTU 8 serves a large conference room; RTU 9 serves several other common spaces (e.g. building lobby and reception areas). Each RTU serves less than 25,000 SF. There are 18 additional spaces - lounges and private offices - which rely primarily on individual PTACs and operable windows for outdoor air. Many of these spaces are identical (e.g. Five identical lounges, one on each floor). For the first floor spaces served by RTUs, we propose to test 1 location per RTU in keeping with the credit requirements. For the remaining 18 spaces which rely primarily on PTACs and operable windows for outdoor air, we propose to test each unique space. For the identical spaces, we propose to test 1 in 7 of each type. (11 tests total) Residential: The majority of the building comprises 144 residential units, all of which are identical in terms of finish, materials and usage. There are 15 different unit types total. Five of the unit types are single occupancy apartments, accounting for 12 units; with no more than 5 of each apartment type. The 10 remaining unit types are dorm suites, accounting for 132 units. Each type of dorm suite is a different configuration of the same elements: a common living/kitchen space, a bathroom, and single or double bedrooms. (Unit type 4A has a living/kitchen area, a bathroom and 4 single bedrooms; unit type 4B has a living/kitchen area, bathroom, and 2 double bedrooms; etc.) Each bedroom and living/kitchen space has a dedicated PTAC, and relies primarily on the PTAC and operable windows for outdoor air. For the 12 single occupancy apartment units (representing 5 unit types), we propose to test one of each unit type. For the 132 dorm suites (representing 10 unit types), we propose to test at least 3 examples of each identical space that composes the suites. That is, we will test 3 single bedrooms, 3 double bedrooms, 3 living/kitchen areas and 3 bathrooms at minimum. These tests will be selected such that there is at least one test in each unit type and at least one test per floor. (17 tests total) All test locations will be selected according to the guidance provided in the reference guide (3-6 ft from floor, in the location anticipated to have the least ventilation and highest presumed source strength, etc.). We feel that providing 35 tests is more than adequate for a 140,000 SF building. Please indicate whether this approach will meet the credit intent or provide additional guidance if it will not.

Ruling:

The applicant is requesting clarification to confirm if the proposed sampling locations are acceptable for each space type given the specific project information provided. It should be noted that although a random sampling plan may be employed per CIR Ruling dated 5/30/2007, contiguous areas served by multiple RTU units, such as the corridors, are considered separate ventilation zones. The proposed sampling locations, by space type, are considered as follows: Corridors: Each of the 5 contiguous corridors is served by 7 separate RTU units for a total of 35 similar ventilation zones. The sampling strategy of insuring that each RTU and each floor will be represented, along with any unique configuration areas, is consistent with the allowable random sampling strategy and does not exceed 7 locations per sample. Therefore 7 sampling locations are acceptable for the corridor areas. Non-Residential: For the first floor RTU unit 8, serving a single space with an area less than 25,000 sq.ft., a single sampling location is acceptable. For the first floor RTU unit 9, serving multiple spaces with a combined area less than 25,000 sq.ft., a single sampling location is acceptable provided the areas represent a single ventilation zone. If the areas served by RTU unit 9 are not a single ventilation zone, each area must be sampled individually. It should be noted that if 2 or more of the areas served by RTU unit 9 are identical, a sampling strategy may be employed provided that no greater than 7 identical locations are represented by a single sample. For the remaining 18 spaces, the proposed sampling strategy is acceptable as each unique space is sampled and no greater than 7 identical locations are represented by a single sample. Residential: For the 12 single occupancy apartment units, it is acceptable to employ a sampling strategy of one sample per unit type, as no greater than 7 identical units will be represented by a single sample. For the 132 dorm suites, it is not clear from the description that no greater than 7 identical units will be represented by a single sample and it does not appear that a minimum of 3 samples will be taken for each identical configuration. Therefore, this strategy is only acceptable if no greater than 7 identical units are represented by a single sample or if a minimum of 3 samples are taken for each identical unit type. It should be noted that although 3 samples are proposed for each component part of these units, the mixing of air may be variable depending on the specific configuration of spaces within the unit. Therefore, each of the 10 unit type configurations must be considered individually when determining sampling strategies.

Campus Applicable
No
Internationally Applicable:
No
12/6/2005
LEED Interpretation
Inquiry:

The following is an alternative compliance path to EQc3.2 for the testing procedure for the detection of 4-PCH: BACKGROUND: The project is a small 1-storey office building. An indoor air quality testing procedure was conducted prior to occupancy in compliance with the EPA referenced standard. The report indicated that all levels were below the required limits except 4-PCH. Unfortunately, the detection limit of the equipment used for 4-PCH was 18-23ug/m3. The maximum 4-PCH level required by the IAQ testing protocol for LEED is 6.5ug/m3, based on the precendent from CIR ruling 11/29/2004. 4-PCH is a contaminant almost exclusively found in carpet backing using Styrene-butadiene latex rubber (SBR). The carpet installed has SBR backing but also complies with the requirements of EQc4.3, which limit the level of 4-PCH to less than 0.05 ug/m2/h, in keeping with the Carpet and Rug Institute\'s Green Label specifications. The project cannot retest for 4-PCH with more sensitive equipment because the building has been occupied for some time now, so the results would be meaningless at this point. We believe we can demonstate compliance to the 4-PCH level requirements through an alternative path, which involves calculating the maximum emissions possible and comparing this with the LEED requirement: Although the carpet contains SBR backing, it does meet the Carpet and Rug Institute\'s Green Label specifications for 4-PCH, which are 0.05 ug/m^2/h. Given that the gross square footage of the building is 9,000 SF (836.4 m^2) and the average ceiling height is 15 FT, the volume is therefore 135,000 FT^3 (3,823 m^3). If we assume the carpet emits 4-PCH at a rate of 0.05 ug/m^2/h (maximum possible emission factor for compliance), then the maximum emission rate the whole carpet could have, if applied to the entire floor area, is: (0.05 ug/m^2/h) x (836.4 m^2) = 41.8 ug/h. Therefore, the maximum 4-PCH emissions that could possibly contaminate the indoor air (without even considering the introduction of outdoor air) is: (41.8 ug/h) / (3,823 m^3) = 0.011 ug/m^3/h Since the maximum 4-PCH level required by the IAQ testing protocol for LEED is 6.5 ug/m^3, it would take 590 hours (25 days) for the 4-PCH to reach this level, if the carpet were inside a sealed box with the same inside volume as the building. Since the carpet is not in a sealed box, and since there will be at worst case conditions at least 25% outdoor air mixed into the air stream, it is reasonable to assume that the 4-PCH levels will never reach 6.5 ug/m^3. We believe this calculation method demonstrates compliance with the credit requirements for 4-PCH levels.

Ruling:

Your proposed calculation method, in combination with the air quality testing, is acceptable to demonstrate achievement of this credit - with two qualifications. First, you state that, "all levels were below the required limits except 4-PCH". From your proposal, we assume that the results for 4-PCH were "non-detect", but you do not specifically state that this is the case. Clearly, your proposed method only works if your test results indicated "non-detect" for 4-PCH. Second, in order to solidify your approach: instead of making a final assumption, complete the calculation by estimating the 4-PCH steady state. Employ a simple calculation for the building as a whole. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
3/7/2005
LEED Interpretation
Inquiry:

We are planning on performing a 2 week building flush out as required by EQ cr3.2. Due to schedule constraints, it would be helpful if the Owner were allowed to set up used, moveable office partitions, and install new auditorium seating during the flush out period. The used, moveable office partitions are from another building, and have, theoretically, already off-gassed. Would it be acceptable to perform one or both of these operations during flush out?

Ruling:

Several CIRs have addressed this issue, including CIR ruling 12/21/2004, "Note that LEED-NC prefers, but does not require, the flush to occur before furniture installation." The proposed furniture installation schedule, though not recommended, would still be acceptable under this credit. Applicable internationally.UPDATE 10/1/12: this LEED Interpretation is not applicable to LEED-CI. Furniture must be installed before the flush-out for LEED-CI projects.

Campus Applicable
No
Internationally Applicable:
Yes
9/5/2006
LEED Interpretation
Inquiry:

The East and North Wing Addition project Hospital is comprised of two phases, three new additions totaling 167,580 GSF and renovations of 25,065 GSF. From the owner\'s perspective, these are two separate sub-projects. The overall project includes two attached and one detached building additions, respectively: a) The North Building Addition, at 30,850 new GSF, will house the relocated Central Sterile Supply (CSS), Surgery Expansion (OR) and Food Services Expansion, along with a Mechanical Room to support the new building. This building, which ties the Main Hospital to the Central Plant at the Ground Level, is designed for both vertical (three floors plus a mechanical penthouse) and horizontal expansion to the North. Included within this section is a planted green roof. b) The East Building Inpatient Tower, totaling 136,730 new GSF, will accommodate the relocation of the Intensive Care Unit (ICU), Emergency Department (ED) expansion, Telemetry Care Unit (TCU), and more Orthopaedic Inpatient beds, as well as a new Lobby, Mechanical Room and Mechanical Penthouse to support the new tower. This tower also includes two shelled floors - the fitout of one floor is an alternate still under consideration at this time. A walled garden off the Level 2 ICU rooms is included to screen patients from motorists and pedestrian traffic. c) A detached metal building, to match the existing Central Plant in appearance, will be constructed to house a new and one future chiller, a cooling tower and a future additional cooling tower. An additional cooling tower replacement and associated piping work is also scheduled within the original Central Plant. We proposed to comply with this credit in the following way: New Construction: In this section, the two-week flush out period will be completed. Renovation: Since this section is renovation, tying into new and existing mechanical systems and accomplished in multiple sub-phases, we propose to comply with EQ3.2 for this portion using the testing methods identified in CIR dated 10/8/2002. Is this approach to compliance is acceptable?

Ruling:

The building flush-out and IAQ testing strategy proposed is acceptable, provided that existing spaces are protected from construction-related contamination as well as prevention of cross-contamination between systems. Protection measures should follow the SMACNA Guidelines for Occupied Buildings and be outlined in the Construction IAQ Management Plan to ensure compliance.

Campus Applicable
No
Internationally Applicable:
No
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Requirements

Develop an (IAQ) management plan and implement it after all finishes have been installed and the building has been completely cleaned before occupancy.

Option 1. Flush-out1
Path 1
After construction ends, prior to occupancy and with all interior finishes installed, install new filtration media and perform a building flush-out by supplying a total air volume of 14,000 cubic feet of outdoor air per square foot (4,500 cubic meters of outdoor air per square meter) of floor area while maintaining an internal temperature of at least 60° F (15° C) and relative humidity no higher than 60%.

OR

Path 2
If occupancy is desired prior to completion of the flush-out, the space may be occupied following delivery of a minimum of 3,500 cubic feet of outdoor air per square foot (1,000 cubic meters of outdoor air per square meter) of floor area. Once the space is occupied, it must be ventilated at a minimum rate of 0.30 cubic feet per minute (cfm) per square foot (0.1 cubic meters per minute per square meter) of outside air or the design minimum outside air rate determined in IEQ Prerequisite 1: Minimum Indoor Air Quality Performance, whichever is greater. During each day of the flush-out period, ventilation must begin a minimum of 3 hours prior to occupancy and continue during occupancy. These conditions must be maintained until a total of 14,000 cubic feet per square foot (4,500 cubic meters per square meter) of outside air has been delivered to the space.

OR

Option 2. Air testing
Conduct baseline IAQ testing, after construction ends and and prior to occupancy using testing protocols consistent with the EPA Compendium of Methods for the Determination of Air Pollutants in Indoor Air or as the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO. Demonstrate that the contaminant maximum concentrations listed below are not exceeded:

Contaminant

Maximum Concentration

EPA Compendium method

ISO method

Formaldehyde

27 parts per billion

IP-6

ISO 16000-3

Particulates (PM10)

50 micrograms per cubic meter

IP-10

ISO 7708

Total volatile organic compounds (TVOCs)

500 micrograms per cubic meter

IP-1

ISO 16000-6

4-Phenylcyclohexene (4-PCH) *

6.5 micrograms per cubic meter

IP-1

ISO 16000-6

Carbon monoxide (CO)

9 parts per million and no greater than
2 parts per million above outdoor levels

IP-3

ISO 4224

*This test is required only if carpets and fabrics with styrene butadiene rubber (SBR) latex backing are installed as part of the base building systems.

For each sampling point where the maximum concentration limits are exceeded, conduct an additional flush-out with outside air and retest the noncompliant concentrations. Repeat until all requirements are met. When retesting noncompliant building areas, take samples from the same locations as in the first test, although it is not required. Conduct the air sample testing as follows:
  • All measurements must be conducted prior to occupancy, but during normal occupied hours with the building ventilation system started at the normal daily start time and operated at the minimum outside air flow rate for the occupied mode throughout the test.
  • All interior finishes must be installed, including but not limited to millwork, doors, paint, carpet and acoustic tiles. Movable furnishings such as workstations and partitions should be in place for the testing, although it is not required.
  • The number of sampling locations will depend on the size of the building and number of ventilation systems. The number of sampling locations must include the entire building and all representative situations. Include areas with the least ventilation and greatest presumed source strength.
  • Air samples must be collected between 3 and 6 feet from the floor to represent the breathing zone of occupants, and over a minimum 4-hour period.

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Should we install furniture and furnishings before IAQ testing or flushout?

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The air temperature and/or relative humidity went out of the credit requirement specifications for a portion of the flush-out. What do we do? Can we extend the flush-out for the equivalent amount of time to make up for it?

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5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add in after "...at normal daily start times and at the minimum outside airflow rate.", "For projects with standardized identical construction, such as classrooms in a school or multifamily residential units, identify which rooms are identical in construction, finishes, configuration, square footage, and HVAC systems. For these scenarios, project teams can sample the identical spaces by testing one in seven."
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add "and the ISO methods" after "The protocols described in the referenced publication, EPA\'s Compendium of Methods for the Determination of Air Pollutants in Indoor Air,"
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 8/14/2020
Reference Guide Correction
Description of change:
In the fourth paragraph, add in after "...the greatest presumed contaminant source strength", "Determine the number of ventilation systems serving the building. Then, determine if the individual floor plates served by each single ventilation system are larger or smaller than 25,000 square feet. If they are smaller, take at least one sample for every 25,000 square feet, or fraction thereof, served by a single ventilation system. If they are larger, take one sample per floor plate. For example, a 110,000 square foot building with ten 11,000 square foot floors, served by a single ventilation system, needs only five samples - one per 25,000 square feet (or fraction thereof) because each 11,000 foot floor plate is smaller than 25,000 square feet. However, a building with ten 30,000 square foot floors, also served by a single ventilation system, needs ten samples for the building because each 30,000 floor plate is larger than the 25,000 sq ft criterion." Delete, "For example" in the following sentence.
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 2/14/2015
Rating System Correction
Description of change:
(1) In the first sentence of the paragraph, replace the text "and as additionally detailed in the LEED Reference Guide for Green Building Design and Construction, 2009 Edition" with "or the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO"(2) In the table, insert two columns to the right (refer to supplementary guidance)(3) In the third bullet item, replace the second sentence (begins with "For each portion") with "The number of sampling locations must include the entire building and all representative situations."
Campus Applicable
No
Internationally Applicable:
No
5/9/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
(1) In the first sentence of the paragraph, replace the text "and as additionally detailed in the LEED Reference Guide for Green Building Design and Construction, 2009 Edition" with "or the ISO method listed in the table below. Testing must be done in accordance with one standard; project teams may not mix requirements from the EPA Compendium of Methods with ISO"(2) In the table, insert two columns to the right (refer to supplementary guidance)(3) In the third bullet item, replace the second sentence (begins with "For each portion") with "The number of sampling locations must include the entire building and all representative situations."
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for occupied spaces, "Occupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space."
Campus Applicable
No
Internationally Applicable:
No
11/2/2009Updated: 2/14/2015
Reference Guide Correction
Description of change:
To the left side of graph, remove a zero from the number "60000" so it becomes "6000"
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for nonoccupied spaces, "Nonoccupied spaces are defined as spaces designed for equipment and machinery or storage with no human occupancy except for maintenance, repairs, and equipment retrieval."
Campus Applicable
No
Internationally Applicable:
No
10/1/2012Updated: 2/14/2015
Reference Guide Correction
Description of change:
In the second paragraph, add in "optionally" before "including furniture and furnishings" so the sentence reads, "After construction and installation of all finishes (optionally including furniture and furnishings)."
Campus Applicable
No
Internationally Applicable:
No
8/1/2011
LEED Interpretation
Inquiry:

Overview: This CIR applies to Option 2- Air Quality Testing. With regards to the process to demonstrate that the maximum TVOC concentrations are below 500 micrograms/cubic meter, this CIR is requesting the acceptance of an alternate unit of measure based on a volumetric reading from an instantaneous, direct reading photoionization detector instrument (PID) using a 10.6 eVolt lamp. This reading would be recorded in a ppb (parts per billion) measurement and then converted to the designated unit of measure called out in the requirements (micrograms/cubic meter) using a conversion factor. This direct reading approach for TVOC will offer a more economical solution for IAQ testing by a factor of approximately two for our ~480,000 SF project. Methodology A conversion factor has been developed (by EH&E in Newton, MA) and is based on a TVOC "fingerprint" of 33 individual volatile organic compounds grouped by chemical category, resulting from a technical evaluation of the Building Assessment Survey Evaluation (BASE) data, the EPA TO-15 list of VOC\'s, and other relevant technical data. The EH&E team examined three lists of indoor VOC\'s to develop the TVOC "fingerprint." These lists originated the following sources: BASE dataset for commercial buildings, PID-readable chemical compounds, and an EPA approved list of indoor VOC\'s. Seven individual VOC\'s from the BASE data the had the highest reported concentrations and could be measured by a PID formed an initial, preliminary fingerprint. These individual VOC\'s were chemically regrouped (i.e. alcohols, halogenated hydrocarbon, aliphatics, etc.) and the relative group proportions in the fingerprint were compared with the BASE dataset. Based on the EPA guidance and a review of indoor VOC literature, additional VOC\'s not measured in the BASE dataset were considered for inclusion. By mapping additional pollutants from the EPA TO-15 list of VOC\'s, EH&E modified the fingerprint to represent new or existing buildings. The expanded list of compounds included all BASE compounds that were both on the EPA TO-15 list and measurable by the PID. This "fingerprint" is based on the following list of chemicals, sorted by their group, their average group molecular weight (AGMV), the % in BASE data, and specific compounds in fingerprint: Format given in following order: Group/AGMW/% in BASE/Compounds in Fingerprint Aldehydes/44.06/12%/Acetaldehyde Alkanes & alkenes/113.6/8%/n-undecane; n-decane; Nonane; Octane; n-hexane; 1,3 butadiene Aromatics/110.5/14%/d-limonene; a-pinene; Naphthalene; o-xylene; m- & p-xylenes; Ethylbenzene; Styrene; Toluene; Benzene Halogenated Hydrocarbons/130/15%/1,2 -dbromoethane; 1,2, 4-trichlorobenzene; 1, 2, -dichlorobenzene; Trichlorobenzene; 1,3,5 -trimethylbenzene; Chlorobenzene; 1,1 -dichloroethene; Vinyl chloride Alcohols/78.5/31%/2 -butoxyethanol; Phenol; 1 -butanol Ketones/58.1/15%/Acetone Other(e.g. acetates,sulfides, ethers, etc.)/92.55/5%/Butyl acetate; Dimethyl disulfide; Ethyl acetate; Carbon disulfide; t-butyl methyl ether Conversion Factor In order to convert a PID reading from part per billion (ppb) to a mass-based equivalent in micrograms/cubic meter, the PID value is multiplied by a derived conversion factor, MCF, defined below as the product of two correction factors, CF-1 and CF-2. For the TVOC fingerprint listed above, the formula is MCF = CF1 * CF2, where MCF = 2.70 Mass Conversion Factor CF1 = 0.88 Correction for predicted ppb PID reading to "actual" ppb reading, based on isobutylene equivalents, and CF2 = 3.07 Correction for "actual" ppb to micrograms/cubic meter equivalent, based on the chemical distribution of the mixture and the average molecular weight. Summary The acceptance of this CIR would provide a lower cost test for TVOCs, including the use of both hand held PID-TVOC direct read instruments and permanently installed PID-TVOC direct read instruments.

Ruling:

**Update January 1, 2014: This Interpretation is no longer valid. See LI 2467.
**Update October 1, 2013
The applicant is requesting approval for use of a photoionization detector instrument (PID) to measure TVOC concentrations during air quality testing. The proposed alternative for testing of TVOC using a PID is not an approved method in the United States Environmental Protection Agency Compendium of Methods for the Determination of Air Pollutants in Indoor Air which are the methods required for this credit. The IAQ testing must be conducted according to the test procedure outlined in the referenced standard using an approved indoor TVOC measurement device, which is either Method IP-1A, Stainless Steel Canister, or IP-1B, Solid Adsorbent Tubes. Both of these methods utilize GC/MS analyses to determine the concentrations of the collected VOC\'s. Most laboratories will calculate the total concentration of VOC\'s (TVOC) according to a toluene equivalent mass from the Total Ion Chromatogram (not just the peaks of EPA TO-15 compounds, but the integrated area of the peaks from all compounds). This method is discussed in the California Department of Health Services (CDHS) Standard Practice. http://www.ciwmb.ca.gov/greenbuilding/Specs/Section01350 First of all PID analyses miss many of the common indoor VOC\'s such as aldehydes and aliphatics and has a poor response factor (i.e. and thus large uncertainty) for common indoor VOC\'s such as alcohols. The "fingerprint" method proposed for calibration of the PID is fundamentally flawed in that it uses a calibration based upon an assumed fixed percentage of mass of VOC\'s from seven different groups of VOC\'s while the actual mass percentage of VOC\'s can vary widely from building to building. The errors associated with the "fingerprint" method could be easily demonstrated by simultaneously measuring the TVOC concentration with a PID and either method IP-1A or IP-1B in a number of buildings. Such a comparison was conspicuously missing from the EH&E report "Development of a Method to Convert Total Volatile Organic Compound Measurements in Buildings to Equivalent Mass Based Units", although the report did contain numerous caveats regarding the accuracy of the "fingerprint method" including limitations related to the "Representativeness of TVOC List" and the "Variability by Building Type". Additionally, the LEED-NC v2.2 Reference Guide states that samples must be collected over a minimum 4-hour period; instantaneous TVOC measurements do not satisfy this requirement.Applicable internationally.

Campus Applicable
No
Internationally Applicable:
Yes
5/30/2007
LEED Interpretation
Inquiry:

We have a ~100,000 square foot 3-pointed T-shaped building with five floors. On the first floor there is an additional 7,800 sq. ft single story extension that will be used for a cafeteria and kitchen. The other sections are approximately 5,500 sq. ft. on each of floors 1 - 5 for a total of approximately 16,500 sq. ft. per floor. Each section is attached to a core and has similar furnishings and usage including both open and private offices and conference/training rooms with the following exceptions: the first floor includes an entrance lobby and the second floor includes a movable filing area and a server room. The HVAC system utilizes variable air volume boxes with induction fans. Separate air handling units (AHUs) in each section on each floor serve the three main vertical sections. There is one outdoor air fan on the roof above each section (3 total) which supply outside air down to the respective sections\' five AHUs. There are an additional nine ceiling-mounted AHUs for the cafeteria and one unit for the kitchen. These ten units are supplied with outside air through one rooftop intake fan that is ducted to each unit. In summary, there are fifteen main AHUs, nine cafeteria AHUs, and one kitchen AHU (25 total). If one were to interpret a "separate ventilation system" as each individual AHU, this would infer 25 sampling locations, which is pointlessly excessive and costly for a 100,000 square foot building. It risks returning to the days when no IAQ testing was done because there was no cost effective protocol in the LEED credit system. We see no technical reason why the criterion should be based on individual AHUs. Identical AHUs used to serve multiple zones all deliver the same volume of outside air per person per ASHRAE requirements for the respective space use. The volume of outside air in supply air varies with time, not by zone i.e. with variations in outside air temperature. The point sources of indoor air pollutants in and around the building and its mechanical system, and their treatment, will be independent of the number of air handling units used to serve the building. If a building designer uses one four-ton AHU vs. four identical one-ton AHUs, what will sampling in four locations achieve? Due to the unique T-shaped design, the building core breaks what would have been contiguous floors into separate areas. While these areas are not physically contiguous, they have similar furnishings and space usages, which present similar indoor pollutants. In order to re-establish an economically and logistically sound method for wide use across multiple building formats, we have selected this project to seek clarification on the following terms: 1) "separate ventilation system" in a building with numerous AHUs and 2) "contiguous floor area" in unusually shaped buildings. We propose that for each portion of the building served by a separate ventilation system, the number of sampling points must not be less than one per 25,000 square feet, or for each contiguous floor area, whichever is larger, with the following clarifications: 1) Allow contiguous floor area to be defined as areas with similar furnishings and space usage, even if the space crosses a building core (but not up or down a floor). 2) Require at least one sample in each building use location, i.e.. cafeteria vs. office vs. warehouse (server rooms are not included since they are not regularly occupied). 3) Allow "separate ventilation system" to be defined as fundamentally different HVAC designs, i.e.. heat pumps vs. built-up units vs. TDV (underfloor) vs. overhead mixing. Following the above protocol, we propose to sample six locations in this building: 1st Floor Cafeteria 1st Floor Lobby 2nd Floor Filing Area 3rd Floor Private Office 4th Floor Training Room 5th Floor Open Office (A "separate ventilation system" could be interpreted as AHUs served by a common outside air source. This would require excessive sampling in buildings equipped with small rooftop package units and thus is not practical.)

Ruling:

Per the LEED-NCv2.2 requirements, the number of sampling sites would be one per each of the separate ventilation systems. The NCv2.2. requirement for one sampling location in "each portion of a building served by a separate ventilation system" is based upon the fact that the ventilation systems define a distinct mixed volume of indoor air as tested under the required minimum outside air percentage mode. Since there may be expected to be variations in the indoor air concentrations in this mixed zone, there is a further requirement that the area in the zone with the least ventilation and greatest presumed contaminant source strength be tested. The contaminants in this mixed volume of air are determined by the emissions from the materials in the air space and the amount of outside air being delivered to the air space. As both the materials and the outside air delivery rates in different ventilation system zones can vary, separate air contaminant measurements are required for each ventilation system zone. If the delivery of outside air on an air change per hour basis and the materials in a ventilation zone are identical (e.g. a specific type of hotel room, or apartment/condominium with separate ventilation systems) a HERS random sampling plan may be employed (i.e. random 1 in 7 selection from each model of room). In addition, for buildings with large numbers of identical rooms each with separate ventilation systems, a minimum of 3 rooms for a particular model of room shall be deemed sufficient. If one or more of the three measurements made per model room fail than an additional three of that type guest room be tested. All failed rooms will be re-tested following flushing with outside air. In this specific case, if the cafeteria space is one undivided open space with identical (not just similar) materials throughout the space and the delivery of outside air on an air change per hour basis is identical for each system, then a HERS random air sampling of 1 in 7 of the 9 ventilation system zones is acceptable. Thus, 2 test locations are required for the cafeteria space (i.e. randomly select 2 of the 9 ventilation system zones) and these locations shall include the area with the least ventilation and greatest presumed contaminant source strength in each zone. The kitchen, which is both a separate space with a separate ventilation system and different materials requires a second test location. Again, to include the area with the least ventilation and greatest presumed contaminant source strength is acceptable. The five floors of the main building with three separate ventilation systems that serve separate spaces with different materials requires one sampling location per ventilation system, again to include the area with the least ventilation and greatest presumed contaminant source strength is acceptable. Thus, a total of 18 test locations are required, two in the cafeteria, one in the kitchen and 15 in the main building.

Campus Applicable
No
Internationally Applicable:
No
10/8/2008
LEED Interpretation
Inquiry:

The 9/5/2006 allows projects to provide both IAQ testing and building flush-out in different construction phases. We intend to provide IAQ testing and building flush-out in different areas of the building within the same construction phase. Our project is a high school addition/renovation that will be occupied in phases. The first phase of construction is complete and those spaces were tested, prior to occupancy, based on the credit ruling dated 10/8/2002. The second phase of the project includes a pool and academic spaces. We are concerned that the chemicals used in the pool will adversely impact the testing results. We therefore propose flushing out that space, using the \'purge mode\' on the pool\'s mechanical unit. Based on the 9/8/2004 credit ruling, we will achieve 14,000 cu ft of outdoor air per square foot of floor space in less than 5 days. As the rest of the Phase 2 areas will not meet the flush-out criteria prior to the scheduled occupancy, we therefore intend to provide IAQ testing in the remaining portions of the building. Until both the IAQ testing and the flush-out is complete, we will prevent cross-contamination between areas. Protection measures will follow the SMACNA Guidelines for Occupied Buildings as outlined in the Construction IAQ Management Plan. Please confirm if the proposed compliance path meets the credit intent. If it is not acceptable, please clarify what changes are required in order to meet the credit requirements.

Ruling:

The applicant is requesting clarification regarding the implementation of flush-out procedures and IAQ testing during the same construction phase. As described, the proposed approach appears to satisfy the credit intent. The indoor air quality problems from construction activity in each space are either reduced from a flush-out or confirmed to be minimal from IAQ testing. Please note, however, that IAQ testing procedures for LEED-NC v2.2 are outlined in the LEED-NC v2.2 Reference Guide and are not identical to the testing procedure outlined in the 10/8/2002 CIR (applicable to LEED-NC v2.1). The reference guide has more stringent maximum concentration requirements and additional testing procedure guidelines. Also note, the air contaminants from swimming pool chemicals, such as chlorine, will not affect the concentration levels tested for this credit. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
7/1/2012
LEED Interpretation
Inquiry:

The project is a training complex in Oklahoma. The new facilities consist of two new B/COF buildings. We intend to conduct baseline IAQ testing, as outlined in option 2. We would like clarification in determining the number of sampling locations within the buildings. The two B/COF buildings each have three floors and encompass approximately 93,000 square feet. For these two buildings, three Dedicated Outside Air Systems (DOAUs) distribute outside air throughout each B/COF building; however, separate Water Source Heat Pumps (WHPs) condition the outside air delivered to each room. Each B/COF building contains 150 residential barracks units which each have a separate WHP. In addition, each B/COF building has identical rooms whose HVAC needs are provided by identical WHP units (e.g., identical offices, identical lounges, and identical learning centers). Following the guidance provided by the LEED for New Construction Version 2009 Reference Guide, each B/COF building would require 184 sampling locations. We propose the following alternative compliance path for multi-family, residential projects with similar rooms and residential units: Per the guidance provided by LI 1740 dated 05/30/2007 , If the delivery of outside air on an air change per hour basis and the materials in a ventilation zone are identical (e.g. a specific type of hotel room, or apartment/condominium with separate ventilation systems) a HERS random sampling plan may be employed (i.e. random 1 in 7 selection from each model of room). In addition, for buildings with large numbers of identical rooms each with separate ventilation systems, a minimum of 3 rooms for a particular model of room shall be deemed sufficient. If one or more of the three measurements made per model room fail, then an additional three of that type guest room are tested. All failed rooms will be re-tested following flushing with outside air. Furthermore, per the guidance provided by LI 5209 dated 04/21/2009, an acceptable strategy for each individual unit type configuration, is a minimum of 3 samples are taken for each identical unit type. (Note: In this case, the minimum of 3 samples refers to three Indoor Air Quality (IAQ) sampling locations for each similar unit type.) Implementing the minimum of three (3) rooms for a particular model of room, we estimate that a total of twenty-seven (27) sample sets will be required in each B/COF building. Per this methodology, identical Dwelling Units will be grouped together and a minimum of 3 sampling locations will be included in the Indoor Air Quality Testing. In the same manner, similar room types with identical ventilation units and rates (i.e. computer learning rooms) will form a separate group upon which a minimum 3 sampling locations will be included. As stated above, this methodology is based on the LI 1740 dated 5/30/2007 for LEED NCv2.2 and LI 5209 dated 04/21/2009. For this project, all Dwelling Units are identical. In each B/COF building, 6 WHP\'s serve 6 identical Dwelling Units and the corridors on the Northeast and Northwest corners of each floor. Although corridors are not considered occupied space per ASHRAE 62.1-2007, the delivery of outside air on an air change per hour basis and the materials in these ventilation zones differ from the remaining Dwelling Units. Per this methodology, these 6 Dwelling Units will be grouped together and 3 sampling locations will be included in the Indoor Air Quality Testing. The remaining 144 identical Dwelling Units are served by separate identical WHP\'s and 3 sampling locations will be included. The remaining groups are served by identical WHP\'s per group, and thus will include 3 samples each for the identical Drill Instructor Rooms (1 per floor), identical Laundry/Vending Rooms (1 per floor), identical Day Rooms (1 per floor), and identical Computer Learning Rooms (1 per floor) for a total of 12 sampling locations. For zones without identical rooms each served with separate ventilation systems, the original guidance will be followed, and the number of sampling locations for each separate ventilation system will not be less than 1 per 25,000 square feet or for each contiguous floor area, whichever is larger. Thus, an additional 9 sampling locations will be included. Please confirm if this alternative compliance path meets the credit intent. If this is not acceptable, please clarify how the IAQ testing option may be applied to projects with identical residential units or rooms that have separate ventilation units but equal ventilation rates based on air changes per hour and identical materials within each unit or room.

Ruling:

The project is inquiring if the proposed sampling for two barrack buildings, each with 150 residential barrack units, offices, lounges, and learning centers satisfies IEQc3.2, Construction IAQ Plan Before Occupancy. As stated in LEED Interpretation 1740, a sampling approach according to HERS guidelines of one in seven of identical spaces is acceptable. Therefore each sample group would consist of identical spaces, one out of every seven of which are to be tested. The LEED Interpretation also allows for a minimum of 3 tests in each sample group, if there are more than 21 identical spaces in a sample group. For example, one sample group might have 1 unit/space in it and another might have 50 identical unit/spaces in it. You would test one in the first sample group, and a minimum of three in the second sample group. Without more information on the number of identical spaces in each sample group, it is unclear if the proposed option completely satisfies the requirements. Note that HERS has specific guidelines in case of test failures in order to continue with a sampling approach. The sampling plan developed for the project, must observe HERS guidelines on what to do in the event of a test failure.

Campus Applicable
No
Internationally Applicable:
No
3/8/2004
LEED Interpretation
Inquiry:

This question concerns allowable contactor activities before, during, and after the required two week flushout period. Your response of 10/17/2001 on this credit seems to imply the following sequence of events: 1. Complete punch list 2. Perform flushout 3. Install furniture The implied reason for this is that the furniture will become a "sink" for indoor pollutants, if installed before the flushout. In our project, the contractor\'s work includes furniture installation. Furthermore, they expect to do touch up painting after move-in, since the movers are likely to cause some damage to building finishes. Following the logic of the 10/17/01 decision, this would be prohibited, as the touch up painting would have to be performed before the flushout, but the furniture move-in, which created the need for touch up, could not be allowed until after flushout. On the other hand, it could be argued that the furniture should be moved in before flushout, to give the furniture an opportunity to "off gas". Is the time of furniture move-in critical, relative to the flushout period? If so, when should it occur? Can any activities, such as touch up painting, be performed after the flushout?

Ruling:

The sequence of final construction activities will naturally vary between contractors and depend on the contractor\'s scope of work. It is most critical that the flush-out be conducted AFTER substantial completion of construction (including major IEQ-relevant punch list items) and prior to occupancy. As stated in the EQc3.2 ruling dated 10/17/2001, it is recommended that the flush-out occur prior to furniture installation (with the exception of non-porous items). Touch-up painting resulting from furniture move-in should not be a significant source of indoor air contamination in comparison to the VOC and particulate emissions from the building materials and construction process and need not be completed prior to flush-out. Applicable internationally.UPDATE 10/1/12: Now applicable to 2009 versions of the rating system and not applicable to older versions.

Campus Applicable
No
Internationally Applicable:
Yes
2/23/2006
LEED Interpretation
Inquiry:

This project is a 147,000 call center. The owner procures air quality testing services on all their new and existing buildings and have done so before they ever did any LEED projects. They recognize the value of superior air quality in terms on worker productivity and avoidance of risk. On this new project the contractor was very diligent in ensuring that low VOC paints, adhesives and sealants were used. No wood materials with added Urea formaldehyde were allowed on the project. The contractor collected MSDS sheets on all these materials. All the carpet meets the CRI Green Label Plus certification. The contractor developed and implemented a Construction Indoor Air Quality Management Plan which followed the SMACNA guidelines for buildings under construction. (The project will not achieve the LEED credit EQc3.1 because there was no MERV 13 filtration provided) In order to ensure superior indoor air quality at the new facility the team is employing air quality testing. Along with testing for the elements required for this credit the team will also test for mold. The testing team is utilizing the EPA Protocol for Environmental Requirements, Baseline IAQ and Materials, for the Research Triangle Park Campus, Section 01445 as required per the LEED Reference Guide credit EQ3.2. The team also referred to the guidelines in the LEED CI Reference Guide credit EQ3.2 for air testing in occupied buildings. The testing began before the building was occupied and the tests for Formaldehyde and total VOC\'s appeared to be within the required levels although all results are not yet in. The testing for particulate level was quite high. The cause of the high particulate appears to be dust in the underfloor area and mechanical rooms. Since the initial testing the building has been about 25% occupied. The underfloor areas and mechanical rooms have been cleaned again. The building ventilation system will provide minimum ventilation rate 3 hours prior to daily occupancy and continue while the space is occupied. The rate of outside air will be at least .30 cfm / sq ft. If levels are exceeded the space will be flushed out by increasing the rate of outdoor air during unoccupied hours. Any additional adjustments to the mechanical system will addressed if needed. Additional testing will be done until all the required test samples meet the concentration levels. Can this method be used to meet the requirements to achieve credit EQc3.2?

Ruling:

You are essentially asking if it is acceptable to continue the IAQ testing and contaminant mitigation activity while the building is partially occupied. The owner\'s actions are commendable, but unfortunately your proposal is not acceptable. The referenced EPA standard states that flush-out, retesting, and compliance with contaminant limits must all be completed before occupancy, and the Technical Advisory Group has chosen not to diverge from it. Instead, the TAG recommends that you examine your occupancy and ventilation schedules to see if you conformed to the flush-out schedule described in EQc3.2 ruling dated 9/8/04. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
3/24/2009
LEED Interpretation
Inquiry:

Overview: This CIR applies to Option 2- Air Quality Testing. With regards to the process to demonstrate that the maximum TVOC concentrations are below 500 micrograms/cubic meter, this CIR is requesting the acceptance of an alternate unit of measure based on a volumetric reading from an instantaneous, direct reading photoionization detector instrument (PID) using a 10.6 eVolt lamp. This reading would be recorded in a ppb (parts per billion) measurement and then converted to the designated unit of measure called out in the requirements (micrograms/cubic meter) using a conversion factor. This direct reading approach for TVOC will offer a more economical solution for IAQ testing by a factor of approximately two for our ~480,000 SF project. Methodology A conversion factor has been developed (by EH&E in Newton, MA) and is based on a TVOC "fingerprint" of 33 individual volatile organic compounds grouped by chemical category, resulting from a technical evaluation of the Building Assessment Survey Evaluation (BASE) data, the EPA TO-15 list of VOC\'s, and other relevant technical data. The EH&E team examined three lists of indoor VOC\'s to develop the TVOC "fingerprint." These lists originated the following sources: BASE dataset for commercial buildings, PID-readable chemical compounds, and an EPA approved list of indoor VOC\'s. Seven individual VOC\'s from the BASE data the had the highest reported concentrations and could be measured by a PID formed an initial, preliminary fingerprint. These individual VOC\'s were chemically regrouped (i.e. alcohols, halogenated hydrocarbon, aliphatics, etc.) and the relative group proportions in the fingerprint were compared with the BASE dataset. Based on the EPA guidance and a review of indoor VOC literature, additional VOC\'s not measured in the BASE dataset were considered for inclusion. By mapping additional pollutants from the EPA TO-15 list of VOC\'s, EH&E modified the fingerprint to represent new or existing buildings. The expanded list of compounds included all BASE compounds that were both on the EPA TO-15 list and measurable by the PID. This "fingerprint" is based on the following list of chemicals, sorted by their group, their average group molecular weight (AGMV), the % in BASE data, and specific compounds in fingerprint: Format given in following order: Group/AGMW/% in BASE/Compounds in Fingerprint Aldehydes/44.06/12%/Acetaldehyde Alkanes & alkenes/113.6/8%/n-undecane; n-decane; Nonane; Octane; n-hexane; 1,3 butadiene Aromatics/110.5/14%/d-limonene; a-pinene; Naphthalene; o-xylene; m- & p-xylenes; Ethylbenzene; Styrene; Toluene; Benzene Halogenated Hydrocarbons/130/15%/1,2 -dbromoethane; 1,2, 4-trichlorobenzene; 1, 2, -dichlorobenzene; Trichlorobenzene; 1,3,5 -trimethylbenzene; Chlorobenzene; 1,1 -dichloroethene; Vinyl chloride Alcohols/78.5/31%/2 -butoxyethanol; Phenol; 1 -butanol Ketones/58.1/15%/Acetone Other(e.g. acetates,sulfides, ethers, etc.)/92.55/5%/Butyl acetate; Dimethyl disulfide; Ethyl acetate; Carbon disulfide; t-butyl methyl ether Conversion Factor In order to convert a PID reading from part per billion (ppb) to a mass-based equivalent in micrograms/cubic meter, the PID value is multiplied by a derived conversion factor, MCF, defined below as the product of two correction factors, CF-1 and CF-2. For the TVOC fingerprint listed above, the formula is MCF = CF1 * CF2, where MCF = 2.70 Mass Conversion Factor CF1 = 0.88 Correction for predicted ppb PID reading to "actual" ppb reading, based on isobutylene equivalents, and CF2 = 3.07 Correction for "actual" ppb to micrograms/cubic meter equivalent, based on the chemical distribution of the mixture and the average molecular weight. Summary The acceptance of this CIR would provide a lower cost test for TVOCs, including the use of both hand held PID-TVOC direct read instruments and permanently installed PID-TVOC direct read instruments.

Ruling:

The applicant is requesting approval for use of a photoionization detector instrument (PID) to measure TVOC concentrations during air quality testing. The proposed alternative for testing of TVOC using a PID is not an approved method in the United States Environmental Protection Agency Compendium of Methods for the Determination of Air Pollutants in Indoor Air which are the methods required for this credit. The IAQ testing must be conducted according to the test procedure outlined in the referenced standard using an approved indoor TVOC measurement device, which is either Method IP-1A, Stainless Steel Canister, or IP-1B, Solid Adsorbent Tubes. Both of these methods utilize GC/MS analyses to determine the concentrations of the collected VOC\'s. Most laboratories will calculate the total concentration of VOC\'s (TVOC) according to a toluene equivalent mass from the Total Ion Chromatogram (not just the peaks of EPA TO-15 compounds, but the integrated area of the peaks from all compounds). This method is discussed in the California Department of Health Services (CDHS) Standard Practice. http://www.ciwmb.ca.gov/greenbuilding/Specs/Section01350 First of all PID analyses miss many of the common indoor VOC\'s such as aldehydes and aliphatics and has a poor response factor (i.e. and thus large uncertainty) for common indoor VOC\'s such as alcohols. The "fingerprint" method proposed for calibration of the PID is fundamentally flawed in that it uses a calibration based upon an assumed fixed percentage of mass of VOC\'s from seven different groups of VOC\'s while the actual mass percentage of VOC\'s can vary widely from building to building. The errors associated with the "fingerprint" method could be easily demonstrated by simultaneously measuring the TVOC concentration with a PID and either method IP-1A or IP-1B in a number of buildings. Such a comparison was conspicuously missing from the EH&E report "Development of a Method to Convert Total Volatile Organic Compound Measurements in Buildings to Equivalent Mass Based Units", although the report did contain numerous caveats regarding the accuracy of the "fingerprint method" including limitations related to the "Representativeness of TVOC List" and the "Variability by Building Type". Additionally, the LEED-NC v2.2 Reference Guide states that samples must be collected over a minimum 4-hour period; instantaneous TVOC measurements do not satisfy this requirement.

Campus Applicable
No
Internationally Applicable:
No
10/23/2006
LEED Interpretation
Inquiry:

BACKGROUND This credit interpretation request is specific to interpretation of EQ Credit #3.2 "Construction IAQ Management Plan: Before Occupancy " under version 2.1. The intent of this credit is "to prevent indoor air quality problems resulting from the construction process in order to help sustain the comfort and well-being of construction workers and building occupants". We believe the approach described below will achieve that intent. The Mazankowski Alberta Heart Institute Project is an expansion to the Walter C. MacKenzie Center, an existing active treatment hospital of approximately 2,000,000 square feet of occupied space. The Mazankowski Alberta Heart Institute will connect to the Walter C. MacKenzie Center through several corridors that will be isolated from the main building until the Heart Institute is occupied. The heart institute is a multi-storey building of approximately 350,00 Square Feet of occupied space consisting of 8 occupied floors each with an interstitial floor above to house building systems. The interstitial floors are completely separated from the occupied floors. The ventilation systems serving the building are configured such that central air systems provide 100% outdoor air to all occupied floors from the 2nd floor to the 8th floor. The main and lower levels are served from air systems that re-circulate a portion of the building air. Each occupied floor and each interstitial floor are separated into a minimum of 3 Fire compartments. Supply and exhaust air for each fire compartment can be isolated by closing smoke dampers in the supply and exhaust ductwork serving the respective fire compartment. The construction and occupancy schedule for the project requires that the building be occupied in stages. These stages would be at a minimum fire compartment by fire compartment and more likely floor by floor. REQUEST We are requesting that the USGBC interpret Credit 3.2 to allow "Before Occupancy" flushing to be conducted on a fire zone by fire zone basis for the Mazankowski Alberta Heart Institute. All unoccupied zones would be isolated from the occupied zones by closing the smoke dampers and taping off man doors serving unoccupied zones. The zones being flushed would utilize the main air systems to allow for the two-week building flush out period prescribed in the discussion for EQ Credit #3.2. The 2nd through 8th floors are served by air systems designed to provide 100% outdoor air. Therefore there will be no recirculation of the air from the occupied or flush-out spaces. For the lower and main floors served by a system that permits re-circulated air, these systems will be controlled so that 100% outdoor air is supplied through this system during the flush out period.

Ruling:

The CIR is inquiring if it is possible to conduct the two-week flush-out of a building in stages to allow for a staggered construction completion schedule. The inquiry indicates that the building floors and/or zones can be separated physically from adjacent spaces, to ensure no cross contamination from construction in the incomplete areas, while providing 100% outside air to accomplish the flush out. Previously posted CIR rulings, dated 10/17/2001 and 9/5/2006 approve the process for a staggered flush-out approach, provided that existing spaces are protected from construction-related contamination as well as prevention of cross-contamination between systems. Protection measures should follow the SMACNA Guidelines for Occupied Buildings and be outlined in the Construction IAQ Management Plan to ensure compliance.

Campus Applicable
No
Internationally Applicable:
No
12/1/2007
LEED Interpretation
Inquiry:

The project contains both systems furniture (42" application) for open areas, and modular wall systems (full height application that is demountable and reusable such as the DIRTT system). We are trying to schedule flush-out activities and understand from other CIRs that furniture installation may occur during or after flushout. Are modular walls as described here considered furniture?

Ruling:

Full height, demountable modular walls are essentially the same in form and function as permanent walls and as such are not considered furniture. They must be installed in the building prior to flush-out for the purposes of EQc3.2. Please note that such modular walls potentially affect other LEED credits (such as daylighting and views) and should therefore be included in any calculations and submissions required for those credits as well. Applicable Internationally.UPDATE October 1, 2012: This LEED Interpretation is not applicable to LEED-CI. Furniture must be installed before the flush-out for LEED-CI projects.

Campus Applicable
No
Internationally Applicable:
Yes
11/1/2011
LEED Interpretation
Inquiry:

The project is an 80,000 sf K-12 school located in the pacific northwest. A majority of the building is being conditioned by "standard" mechanical means and can demonstrate compliance according to ASHRAE 55-2004 Figure 5.2.1.1., however there are portions of the building that will be thermally regulated by natural ventilation and with extensive radiant systems.The purpose of this request is to determine whether the more passive, naturally ventilated portion of the building may be considered "naturally conditioned" with their thermal comfort criteria evaluated according to ASHRAE 55-2004 Figure 5.3 rather than being evaluated according to Figure 5.2.1.1.The northwest climate is considered heating dominated with narrow diurnal temperature variations and as a consequence has limited cooling needs, especially during the school year. The need for cooling is isolated to only brief time periods at the beginning and end of the 9-month school year when potential thermal comfort concerns would arise. To mitigate thermal comfort concerns during these isolated times, the design incorporates occupant-controlled operable windows and ceiling fans to allow comfort control within the classrooms. In addition to the operable windows, the design also includes utilizing the thermal massing properties of the concrete floors to better modulate the release of cooling within the space(s). The cooling will be supplied by evaporatively-cooled water via hydronic loops in the floors during the nighttime periods when the building is unoccupied. The intent is pre-charge the thermal mass of the floors with enough cooling to offset the effects of internal heat gains and eliminate the need for active mechanical cooling during the day. Since the charging is taking place during the evenings, there will not be any ability for the occupants to directly call for additional cooling to be added to floor or space and the mass will in essence be allowed to release it cooling naturally trough out the day. Lastly, we are interpreting that this approach of pre-cooling the mass without the need of compressor-based mechanical cooling could be construed as a assisted passive approach, however it is unclear whether the USGBC will recognize these spaces as "naturally conditioned" for the purposes of IEQc7.1. ASHRAE 55-2004, Section 5.3, states that "occupant-controlled naturally conditioned spaces are those spaces where the thermal conditions of the space are regulated primarily by the occupants through opening and closing of windows". We believe that the definition is still being satisfied with the mass pre-charging strategy described previously, since the regulation of the thermal conditions will still be controlled by the occupants through the opening and closing of windows.Can the thermal comfort criteria in these rooms be evaluated according to "naturally conditioned" rather than "typical" criteria and if so, is modeling an acceptable means of documenting compliance?

Ruling:

The applicant is asking whether a space that meets the ASHRAE Standard 55-2004 definition of "naturally conditioned spaces, occupant controlled," but is also served by an in-floor radiant cooling system that is in turn served by an evaporatively-cooled water tower that will be utilized at night to pre-charge the high thermal mass concrete floors, may be evaluated according to ASHRAE Standard 55-2004 Section 5.3 - Optional Method for Determining Acceptable Thermal Conditions in Naturally Conditioned Spaces in lieu of the requirements of Section 5.2 Method for Determining Acceptable Thermal Conditions in Occupied Spaces.Section 5.3 of Standard 55-2004 states, "there must be no mechanical cooling system for the space (e.g. refrigerated air cooling, radiant cooling, or desiccant cooling.)" in order to use the Optional Method for Determining Acceptable Thermal Conditions in Naturally Conditioned Spaces. If the radiant cooling system is operated during the day, the project would be considered mechanically cooled and not eligible to use the Section 5.3 method. However, if the system is operated as described in the Interpretation Request and the radiant cooling system is only used at night as a pre-cooling strategy then the intent and spirit of the conditions for using Section 5.3 are met. Note that:1. For times when active mechanical cooling OR heating is used during occupied hours, Section 5.3 does not apply and Section 5.2 Method for Determining Acceptable Thermal Conditions in Occupied Spaces shall be used.2. In the Cooling season when the night-time pre-cooling strategy is used, the minimum design operative temperatures in the morning shall be evaluated compared to the allowable minimum operative temperature based on Section 5.3 to ensure comfortable conditions throughout the day. Applicable internationally.

Campus Applicable
No
Internationally Applicable:
Yes
4/21/2009
LEED Interpretation
Inquiry:

We are requesting clarification on the number and location of IAQ testing measurements for a 140,000 SF university residence hall project. Based on guidance from previous CIRs for other buildings with large numbers of like spaces, we propose the IAQ testing approach described below: Corridors: The corridors are uninterrupted on each floor and are served by seven 100% outside-air Roof Top Units spaced along the building. Each RTU serves the corridor segments of the floors beneath it. (RTU 1 serves the West section of the corridors on floors 1-5, etc.) The corridors on each floor are identical in terms of materials, finish, usage and, for the most part, configuration. We propose to sample one location for each corridor RTU, with at least one test per floor. Any unique configurations will also be tested. (7 tests) Nonresidential spaces: Two additional RTUs serve several first floor common spaces: RTU 8 serves a large conference room; RTU 9 serves several other common spaces (e.g. building lobby and reception areas). Each RTU serves less than 25,000 SF. There are 18 additional spaces - lounges and private offices - which rely primarily on individual PTACs and operable windows for outdoor air. Many of these spaces are identical (e.g. Five identical lounges, one on each floor). For the first floor spaces served by RTUs, we propose to test 1 location per RTU in keeping with the credit requirements. For the remaining 18 spaces which rely primarily on PTACs and operable windows for outdoor air, we propose to test each unique space. For the identical spaces, we propose to test 1 in 7 of each type. (11 tests total) Residential: The majority of the building comprises 144 residential units, all of which are identical in terms of finish, materials and usage. There are 15 different unit types total. Five of the unit types are single occupancy apartments, accounting for 12 units; with no more than 5 of each apartment type. The 10 remaining unit types are dorm suites, accounting for 132 units. Each type of dorm suite is a different configuration of the same elements: a common living/kitchen space, a bathroom, and single or double bedrooms. (Unit type 4A has a living/kitchen area, a bathroom and 4 single bedrooms; unit type 4B has a living/kitchen area, bathroom, and 2 double bedrooms; etc.) Each bedroom and living/kitchen space has a dedicated PTAC, and relies primarily on the PTAC and operable windows for outdoor air. For the 12 single occupancy apartment units (representing 5 unit types), we propose to test one of each unit type. For the 132 dorm suites (representing 10 unit types), we propose to test at least 3 examples of each identical space that composes the suites. That is, we will test 3 single bedrooms, 3 double bedrooms, 3 living/kitchen areas and 3 bathrooms at minimum. These tests will be selected such that there is at least one test in each unit type and at least one test per floor. (17 tests total) All test locations will be selected according to the guidance provided in the reference guide (3-6 ft from floor, in the location anticipated to have the least ventilation and highest presumed source strength, etc.). We feel that providing 35 tests is more than adequate for a 140,000 SF building. Please indicate whether this approach will meet the credit intent or provide additional guidance if it will not.

Ruling:

The applicant is requesting clarification to confirm if the proposed sampling locations are acceptable for each space type given the specific project information provided. It should be noted that although a random sampling plan may be employed per CIR Ruling dated 5/30/2007, contiguous areas served by multiple RTU units, such as the corridors, are considered separate ventilation zones. The proposed sampling locations, by space type, are considered as follows: Corridors: Each of the 5 contiguous corridors is served by 7 separate RTU units for a total of 35 similar ventilation zones. The sampling strategy of insuring that each RTU and each floor will be represented, along with any unique configuration areas, is consistent with the allowable random sampling strategy and does not exceed 7 locations per sample. Therefore 7 sampling locations are acceptable for the corridor areas. Non-Residential: For the first floor RTU unit 8, serving a single space with an area less than 25,000 sq.ft., a single sampling location is acceptable. For the first floor RTU unit 9, serving multiple spaces with a combined area less than 25,000 sq.ft., a single sampling location is acceptable provided the areas represent a single ventilation zone. If the areas served by RTU unit 9 are not a single ventilation zone, each area must be sampled individually. It should be noted that if 2 or more of the areas served by RTU unit 9 are identical, a sampling strategy may be employed provided that no greater than 7 identical locations are represented by a single sample. For the remaining 18 spaces, the proposed sampling strategy is acceptable as each unique space is sampled and no greater than 7 identical locations are represented by a single sample. Residential: For the 12 single occupancy apartment units, it is acceptable to employ a sampling strategy of one sample per unit type, as no greater than 7 identical units will be represented by a single sample. For the 132 dorm suites, it is not clear from the description that no greater than 7 identical units will be represented by a single sample and it does not appear that a minimum of 3 samples will be taken for each identical configuration. Therefore, this strategy is only acceptable if no greater than 7 identical units are represented by a single sample or if a minimum of 3 samples are taken for each identical unit type. It should be noted that although 3 samples are proposed for each component part of these units, the mixing of air may be variable depending on the specific configuration of spaces within the unit. Therefore, each of the 10 unit type configurations must be considered individually when determining sampling strategies.

Campus Applicable
No
Internationally Applicable:
No
12/6/2005
LEED Interpretation
Inquiry:

The following is an alternative compliance path to EQc3.2 for the testing procedure for the detection of 4-PCH: BACKGROUND: The project is a small 1-storey office building. An indoor air quality testing procedure was conducted prior to occupancy in compliance with the EPA referenced standard. The report indicated that all levels were below the required limits except 4-PCH. Unfortunately, the detection limit of the equipment used for 4-PCH was 18-23ug/m3. The maximum 4-PCH level required by the IAQ testing protocol for LEED is 6.5ug/m3, based on the precendent from CIR ruling 11/29/2004. 4-PCH is a contaminant almost exclusively found in carpet backing using Styrene-butadiene latex rubber (SBR). The carpet installed has SBR backing but also complies with the requirements of EQc4.3, which limit the level of 4-PCH to less than 0.05 ug/m2/h, in keeping with the Carpet and Rug Institute\'s Green Label specifications. The project cannot retest for 4-PCH with more sensitive equipment because the building has been occupied for some time now, so the results would be meaningless at this point. We believe we can demonstate compliance to the 4-PCH level requirements through an alternative path, which involves calculating the maximum emissions possible and comparing this with the LEED requirement: Although the carpet contains SBR backing, it does meet the Carpet and Rug Institute\'s Green Label specifications for 4-PCH, which are 0.05 ug/m^2/h. Given that the gross square footage of the building is 9,000 SF (836.4 m^2) and the average ceiling height is 15 FT, the volume is therefore 135,000 FT^3 (3,823 m^3). If we assume the carpet emits 4-PCH at a rate of 0.05 ug/m^2/h (maximum possible emission factor for compliance), then the maximum emission rate the whole carpet could have, if applied to the entire floor area, is: (0.05 ug/m^2/h) x (836.4 m^2) = 41.8 ug/h. Therefore, the maximum 4-PCH emissions that could possibly contaminate the indoor air (without even considering the introduction of outdoor air) is: (41.8 ug/h) / (3,823 m^3) = 0.011 ug/m^3/h Since the maximum 4-PCH level required by the IAQ testing protocol for LEED is 6.5 ug/m^3, it would take 590 hours (25 days) for the 4-PCH to reach this level, if the carpet were inside a sealed box with the same inside volume as the building. Since the carpet is not in a sealed box, and since there will be at worst case conditions at least 25% outdoor air mixed into the air stream, it is reasonable to assume that the 4-PCH levels will never reach 6.5 ug/m^3. We believe this calculation method demonstrates compliance with the credit requirements for 4-PCH levels.

Ruling:

Your proposed calculation method, in combination with the air quality testing, is acceptable to demonstrate achievement of this credit - with two qualifications. First, you state that, "all levels were below the required limits except 4-PCH". From your proposal, we assume that the results for 4-PCH were "non-detect", but you do not specifically state that this is the case. Clearly, your proposed method only works if your test results indicated "non-detect" for 4-PCH. Second, in order to solidify your approach: instead of making a final assumption, complete the calculation by estimating the 4-PCH steady state. Employ a simple calculation for the building as a whole. Applicable Internationally.

Campus Applicable
No
Internationally Applicable:
Yes
3/7/2005
LEED Interpretation
Inquiry:

We are planning on performing a 2 week building flush out as required by EQ cr3.2. Due to schedule constraints, it would be helpful if the Owner were allowed to set up used, moveable office partitions, and install new auditorium seating during the flush out period. The used, moveable office partitions are from another building, and have, theoretically, already off-gassed. Would it be acceptable to perform one or both of these operations during flush out?

Ruling:

Several CIRs have addressed this issue, including CIR ruling 12/21/2004, "Note that LEED-NC prefers, but does not require, the flush to occur before furniture installation." The proposed furniture installation schedule, though not recommended, would still be acceptable under this credit. Applicable internationally.UPDATE 10/1/12: this LEED Interpretation is not applicable to LEED-CI. Furniture must be installed before the flush-out for LEED-CI projects.

Campus Applicable
No
Internationally Applicable:
Yes
9/5/2006
LEED Interpretation
Inquiry:

The East and North Wing Addition project Hospital is comprised of two phases, three new additions totaling 167,580 GSF and renovations of 25,065 GSF. From the owner\'s perspective, these are two separate sub-projects. The overall project includes two attached and one detached building additions, respectively: a) The North Building Addition, at 30,850 new GSF, will house the relocated Central Sterile Supply (CSS), Surgery Expansion (OR) and Food Services Expansion, along with a Mechanical Room to support the new building. This building, which ties the Main Hospital to the Central Plant at the Ground Level, is designed for both vertical (three floors plus a mechanical penthouse) and horizontal expansion to the North. Included within this section is a planted green roof. b) The East Building Inpatient Tower, totaling 136,730 new GSF, will accommodate the relocation of the Intensive Care Unit (ICU), Emergency Department (ED) expansion, Telemetry Care Unit (TCU), and more Orthopaedic Inpatient beds, as well as a new Lobby, Mechanical Room and Mechanical Penthouse to support the new tower. This tower also includes two shelled floors - the fitout of one floor is an alternate still under consideration at this time. A walled garden off the Level 2 ICU rooms is included to screen patients from motorists and pedestrian traffic. c) A detached metal building, to match the existing Central Plant in appearance, will be constructed to house a new and one future chiller, a cooling tower and a future additional cooling tower. An additional cooling tower replacement and associated piping work is also scheduled within the original Central Plant. We proposed to comply with this credit in the following way: New Construction: In this section, the two-week flush out period will be completed. Renovation: Since this section is renovation, tying into new and existing mechanical systems and accomplished in multiple sub-phases, we propose to comply with EQ3.2 for this portion using the testing methods identified in CIR dated 10/8/2002. Is this approach to compliance is acceptable?

Ruling:

The building flush-out and IAQ testing strategy proposed is acceptable, provided that existing spaces are protected from construction-related contamination as well as prevention of cross-contamination between systems. Protection measures should follow the SMACNA Guidelines for Occupied Buildings and be outlined in the Construction IAQ Management Plan to ensure compliance.

Campus Applicable
No
Internationally Applicable:
No

LEEDuser expert

Dylan Connelly

Integral Group
Mechanical Engineer

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