NC-2009 IEQp1: Minimum IAQ Performance

  • NC Schools IEQp1 credit reqs diagram
  • Baseline for outdoor air ventilation

    This prerequisite establishes a baseline for providing a minimum amount of outdoor air to buildings in order to maintain good indoor air quality and keep occupants comfortable and healthy. This prerequisite references ASHRAE 62.1-2007 (with errata but without addenda) and is often more stringent than local building codes, although it is not likely to entail any added costs.

    Two cases, both may be needed

    The compliance paths for mechanically ventilated and naturally ventilated spaces, Case 1 and Case 2, are somewhat different and you may need to follow both paths for the same building on a space-by-space basis. Spaces served only by natural ventilation must follow the distinct requirements set out in Case 2, even if other spaces in the same building are mechanically ventilated and are following Case 1. Mixed-mode spaces which alternate between natural or mechanical ventilation must follow the compliance path for mechanical ventilation, Case 1.

    For additions and major renovations, confirm that all ventilation systems serving the project meet the ventilation rates required by ASHRAE 62.1 2007, even if the ventilation system design itself is outside the scope of the project. If base building systems do not meet the standard’s requirements, you will need to either increase ventilation rates to comply or provide detailed analysis documenting the constraints and explaining why the base building systems cannot be upgraded.

    There’s some confusion in this language on whether mixed-mode refers to a ventilation design with both natural and mechanical ventilation all the time, which needs to be divided up to show compliance, or to a system where either is optional, in which case the worst-case design conditions are for when only the mechanical systems are used and window are shut.

    Any ventilation systems serving the project are covered

    Commercial interior projects will need to confirm that any ventilation systems serving the project meet the ventilation rates required by ASHRAE 62.1-2007, even if the ventilation system design itself is outside the scope of the project. If base building systems cannot be modified to meet the standard’s requirements, you will need to provide detailed analysis documenting the constraints and explaining why the base building systems cannot be upgraded. Systems must be able to provide at least 10 cfm per person to meet this prerequisite.

    ASHRAE 62.1: 2007 vs. 2004

    The 2007 edition of ASHRAE 62.1 combines  62.1-2004 and the eight approved and published addenda to the 2004 edition. The new edition does the following:

    • Clarifies dehumidification analysis requirements and offers exceptions to the 65% relative humidity limit requirement and to the net-positive intake-airflow requirement.
    • Corrects occupant category inconsistencies and provides additional information for several occupancy categories.
    • Updates references and clarifies the text particularly as related to subjective evaluation of air quality.
    • Updates information to be consistent with the U.S. EPA National Ambient Air Quality StandardsThe level of pollutants prescribed by regulations that are not to be exceeded during a given time in a defined area. (EPA).
    • Includes a new  appendix that summarizes the documentation requirements in the body of the standard, thus providing a single point of reference for users.
    • Requires proper design for buildings that contain both ETSEnvironmental tobacco smoke (ETS), or secondhand smoke, consists of airborne particles emitted from the burning end of cigarettes, pipes, and cigars, and is exhaled by smokers. These particles contain about 4,000 compounds, up to 50 of which are known to cause cancer. and ETS-free areas, by requiring classification of areas based on expected presence of ETS, pressurization of ETS-free areas, separation of ETS and ETS-free areas, and cautionary signage for ETS-areas.
  • FAQs for IEQp1

    A building has fan-assisted ventilation and no mechanical cooling system. Does this qualify as natural ventilation?

    If the building relies on the fans for daily ventilation, it is considered a mechanically ventilated building.

    Is outdoor air quality testing required in a space using natural ventilation?

    Testing in naturally ventilated spaces is not required per 62.1-2007 Sections 4-7 if the outdoor air quality adequately meets 62.1-2007, Table 4-1.

    For a space designed to be naturally ventilated, can operable windows or vents be used to satisfy the 62.1-2007 requirements?

    Both operable windows and vents can be used, but only the operable area within those elements can be counted towards the minimum percentage (4%) of net occupiable area.

    What options are available to projects outside the US to meet this prerequisite?

    Local codes may be used to meet the prerequisite if the project team can show equivalency with Sections 7 through 7 of ASHRAE Standard 62.1-2007. Projects outside the US can now also choose to comply with the minimum requirements of Annex B of CEN Standard EN 15251:2007 Ventilation for Nonresidential buildings.

    Can LEED 2009 projects elect to follow ASHRAE 62.1-2010 for this prerequisite?

    Teams may choose to substitute ASHRAE 62.1-2010, Sections 6.4.1-6.4.2, for ASHRAE 62.1-2007, Section 5.1.1, to document compliance with IEQp1 for naturally ventilated buildings. ASHRAE 62.1-2010 adds geometric requirements that extend the allowed naturally ventilated floor area based on ceiling height and opening configuration.

    Which units should be included in the calculations for this prerequisite?

    For CI projects, calculations must be done at the system level for any AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. providing outside air to the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space..

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Determine likely ventilation strategies during preliminary programming: natural, mechanical, or mixed-mode ventilation. This prerequisite is attainable with any of these strategies.


  • This prerequisite is paired with IEQc2: Increased Ventilation. If ventilation rates are targeted above the 30% ASHRAE requirement, projects can gain both the prerequisite and a point for EQc2. Projects pursuing IEQc2 may follow the compliance path for natural ventilation found in Chapter 2 of The CIBSE Applications Manual 10 (AM10) for both the prerequisite and for the credit.


  • Many of the strategies that contribute to meeting this prerequisite also support earning other indoor environmental quality credits and should be explored as integrated solutions. See LEEDuser's guidance on the rest of the IEQ section for ideas.


  • Natural ventilation strategies can reduce costs. Natural ventilation in particular can reduce the need for mechanical equipment as well as operational costs. Displacement ventilation, in which air is delivered at or near floor level at a low velocity, can also reduce ducting and improve equipment efficiency. In choosing a system, analyze life cycle cost tradeoffs.


  • Check local building codes to determine requirements. The project must either meet ASHRAE 62.1-2007, or local codes if they are more stringent. Since ASHRAE 62.1-2007 is often more stringent than local codes, be sure to review and be familiar with its requirements.


  • This prerequisite is not likely to require added costs.


  • Case 1: Mechanically Ventilated Spaces


  • Review the Ventilation Rate Procedure methodology in ASHRAE 62.1-2007 Section 6.2 and the associated Table 6-1.


  • ASHRAE 62.1 recognizes two procedures to prove IAQ compliance: the IAQ Procedure methodology and the Ventilation Rate Procedure. The Ventilation Rate Procedure is easier to apply and is the prescribed path for this LEED prerequisite. Documentation using the IAQ Procedure requires the quantification of contaminant source emissions rates and their reduction, and has historically not been accepted for this prerequisite because it is performance-based and difficult to compare across projects.


  • If you are pursuing IEQc5: Indoor Chemical and Pollutant Source Control, you must incorporate MERV 13 filters into your filtration system. These relatively tight filters may affect the fan power and fan sizes necessary to provide the required quantities of air. Involve the engineer early if pursuing IEQc5. 


  • Demand-controlled ventilation can greatly reduce energy use while providing large amounts of fresh air to occupants.


  • Case 2: Naturally Ventilated Spaces


  • Determine whether natural ventilation is feasible based on the project type, use, and climate.  Study the natural conditions of the site, such as prevailing wind direction, and orient the building to maximize airflow.


  • Review the prescriptive requirements for natural ventilation in ASHRAE 62.1-2007 Paragraph 5.1 (with errata but without addenda).


  • An integrated design meeting will help determine whether natural ventilation is a high priority and should be a primary driver of the design process.


  • Airflow modeling early in the design process can help teams by evaluating which space planning and envelope design strategies will create effective natural ventilation. An airflow modeling professional may add some upfront costs, while likely improving system efficiency.

 Airflow modeling can also help to determine compliance for an engineered natural ventilation system outside the prescriptive measures of ASHRAE 62.1-2007.


  • Consider the cost implications of natural ventilation. Passive strategies may reduce or eliminate the need for fans and HVAC equipment, but they may also require high quantities of operable windows and a floor plan that is conducive to passive ventilation.  Natural ventilation often requires the cooperation of occupants, to open and close windows when appropriate, for example, be sure that your project is likely to succeed in this respect.

Schematic Design

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  • Determine the required ventilation rates for indoor spaces based on occupancy and space types.  ASHRAE 62.1-2007 tables 6-1 and 6-4 list minimum requirements for particular spaces.


  • Separately evaluate each space to determine air requirements and what type of ventilation will be best.  Metabolic rate of the space activities and the occupant density are factors that determine the amount of fresh air needed in a space.  For example, exercise rooms and conference rooms require more fresh air than offices.


  • An integrated design approach among the mechanical engineer, architects, owners and occupants will facilitate design decisions that impact the HVAC design. For example, space planning decisions will impact the architectural programming of the space as well as access to natural ventilation.


  • Increasing a project’s ventilation rate brings long-term cost benefits. Good indoor air quality can lower operational costs by increasing occupants’ health and productivity as well as the value and marketability of the building.


  • For mixed-mode and naturally ventilated spaces, the mechanical engineer should calculate the outdoor airflow rate and communicate the area requirements for operable wall or roof openings to the architect.


  • The mechanical engineer begins preliminary ventilation rate calculations during project programming in order to set ventilation quality goals for particular spaces and occupancies. The area of a given multi‐zone system should be broken down by ventilation zones, and all zones within that system must meet the minimum breathing zone ventilation air requirements as per ASHRAE 62.1‐2004. For a typical office space, the mechanical design consists of multiple ventilation zones for which compliance would need to be shown on an individual basis.


  • Case 1 Mechanically Ventilated Spaces


  • For mixed-mode ventilation, zone the plan into areas—mechanically ventilated and naturally ventilated—and follow separate compliance calculations for each area.


  • Case 2 Naturally Ventilated Spaces


  • Determine the applicable floor area for operable wall or roof openings according to ASHRAE 62.1-2007 section 5.1.


  • Consider using Computational Fluid Dynamics (CFD) modeling to determine proper opening sizes and ensure proper airflow. Some energy modeling programs also have CFD analysis capabilities.


  • Expect upfront modeling fees for Computational Fluid Dynamics (CFD), but also consider the benefits of CFD modeling: a better-designed natural ventilation system that can bring short-term payback from reduced mechanical systems, and long-term operational savings.


  • At the first integrated design meeting during schematic design, develop a detailed natural ventilation strategy involving goals for windows, building orientation, space planning, use of atriums, and other access to natural ventilation. Natural ventilation systems may require a more robust and intense integrated design process, of several focused workshops analyzing several alternatives. Computer modeling may be necessary to test various design alternatives to determine which is most effective and efficient.


  • Hotel and multifamily projects may have difficulty achieving this prerequisite if they are naturally ventilated and have interior spaces that are further than 25 feet from an operable wall or roof opening. These projects might consider increased window areas, shallower floor plates, or using mixed-mode ventilation so that mechanically supplied outdoor air can support areas outside the 25-foot natural ventilation boundary.

Design Development

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  • The mechanical engineer continues to run ventilation rate calculations during the mechanical design process to inform design development and confirm compliance with this prerequisite. The ventilation rate procedure is explained in section 6 of ASHRAE 62.1-2007. See the attached 62MZ calculator.


  • Continuing to use an integrated design approach among the mechanical engineer, architects, owners and end users will facilitate design decisions that impact the mechanical design. For example, space planning decisions will impact the architectural programming of the space as well as access to natural ventilation.


  • Strategically locate air intakes for mechanical or natural ventilation systems to avoid taking in contaminants and odors like vehicle exhaust from parking lots or fumes from garbage storage areas.


  • Incorporating operable windows into the design for natural and mixed-mode ventilation can help with an additional LEED point for EAc6.1: Controllability of Systems—Thermal Comfort.


  • Case 1: Mechanically Ventilated Spaces


  • Continue running ventilation rate calculations during the mechanical design process to confirm compliance with this credit and to inform the design. The ventilation rate procedure is explained in section 6 of ASHRAE 62.1-2007. See the 62MZ calculator.


  • Implement energy recovery systems, economizers, low-pressure-drop design, and efficient fans as appropriate to support ventilation rates meeting or exceeding the referenced ASHRAE standard without compromising energy performance.


  • Avoid oversizing mechanical equipment. Oversized equipment will often increase operating costs and reduce operational efficiency. The correct equipment size will depend on a number of factors, including local climate, total building area, insulation levels, air filtration medium, number of windows and doors, and occupant comfort preferences.


  • Spaces served by the same VAV (variable air volume) controller can be grouped together in the 62MZ calculator, but grouped spaces should have similar exterior exposure. For example, you can group two perimeter spaces that share a VAV controller, but would want to separate a non-perimeter space even if it shares the same VAV controller.


  • Laboratory facilities generally require very high ventilation rates. Consider installing separate mechanical systems for lab spaces to maximize return-air mixing. Other strategies may include using a heat exchanger to capture energy from laboratory exhaust, using low-flow or variable-flow fume hoods, minimizing ventilation rates during unoccupied times, or using a dedicated outdoor air system.


  • Integrating building automation systems can control mechanical systems efficiently and maintain desired ventilation rates while minimizing unscheduled maintenance.


  • The Ventilation Rate Procedure calculation includes occupancy counts based on space types.


  • Case 2: Naturally Ventilated Spaces


  • Continue to run calculations and develop flow diagrams to inform the design process and confirm compliance. If you are using a natural ventilation modeler for the project, use the model as a tool to inform design development.


  • The calculation for operable openings will only apply to the floor area adjacent to the window—25 feet to either side and in front of the opening.


  • The surface area of window openings must, for compliance with ASHRAE 62.1, be equal to or greater than 4% of the occupied floor area that the design considers naturally ventilated. Multiple windows in aggregate can provide the operable area needed to meet the requirements.


  • In naturally ventilated multifamily buildings, air infiltration from a pressurized hallway or corridor can contribute to the Ventilation Rate Procedure calculation for areas that do not meet the requirements of ASHRAE 62.1, as long as the corridor is pressurized with outdoor air.

Construction Documents

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  • For mechanically ventilated spaces, run ventilation calculations to verify that the final design meets the minimum outside air rates equal to or exceeding the ASHRAE 62.1-2007 minimum.


  • For naturally ventilated spaces, confirm compliance with the requirements of ASHRAE 62.1-2007 section 5.1.


  • If natural ventilation strategies are integrated into the design, ensure that key elements of the natural ventilation system, such as operable windows, window actuators, controls, operable atrium elements, and solar chimneys, are not compromised during value engineering. Educate decision-makers about the natural ventilation design and the importance of maintaining all the key components. If these elements are altered in a way that compromises natural ventilation rates, the mechanical system may no longer be sized appropriately.


  • Fill out the LEED credit form and upload all supporting documents to LEED Online.


  • Use this checklist for naturally ventilated spaces prior to construction to review plans for prerequisite compliance:

    • Are all floor areas within 25 feet of an operable window?
    • Do all floor areas within 25 feet of an operable window appear have 4 ft2 of opening per 100 ft2 of floor area?
    • Is fresh outdoor air mechanically supplied and exhausted for all regularly occupied spaces beyond 25 feet of an operable window?
    • Do any corridors or entryways fall outside of these naturally or mechanically ventilated areas? If so, develop the design further to supply sufficient ventilation.

  • Use this checklist for mechanical systems prior to construction to check prerequisite compliance:

    • Using the mechanical equipment schedule, confirm that outside air is being supplied to mechanically ventilated spaces.
    • Do you have calculations showing the outside air required by ASHRAE 62.1-2007 for mechanically ventilated spaces separate from naturally ventilated spaces?
    • Do outside air rates meet or exceed the calculated ASHRAE minimums?
    • Are all regularly occupied spaces listed in the ASHRAE calculations?
    • What is the desired MERV filtration? If using a high level of ventilation to meet EQc5, has the mechanical system been sized accordingly?

Construction

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  • Coordinate the installation of ventilation systems with the project’s commissioning process.


  • Use commissioning to confirm that installed systems are providing the outside air rates specified in the design. 

Operations & Maintenance

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  • Monitor outdoor air delivery periodically to confirm that minimum ventilation rates are being maintained. Implement a maintenance program to ensure that mechanical system components are functioning properly.


  • Test all dedicated building exhaust systems including chemical areas, bathroom, shower, kitchen, and parking exhaust systems to confirm proper fan speed, voltage, control sequences, and set points as applicable. Provide operations and maintenance personnel with manuals and educate them about any atypical maintenance requirements.


  • Getting feedback on ventilation performance from occupants through surveys can help to identify potential problems that may become expensive if they go unnoticed.


  • A documented ventilation performance plan can help ensure that systems reach the expected ventilation thresholds.


  • In projects with operable windows, occupants may not know when conditions are best for opening the windows. Implement a system so that occupants are informed of when to open and close the windows to achieve designed performance and optimal comfort.


  • Maintain a building operating plan (BOP) that establishes operating schedules and set points and regularly review these parameters against actual building needs. When developing these parameters, consider both time-of-day and time-of-year variations in optimal temperature requirements and be careful to avoid over-conditioning the building spaces with more ventilation, heating or cooling than is necessary.


  • Adjust reset and setback temperature settings and calibrate controls and sensors. A Building Automation System (BAS) will allow building managers to adjust, monitor and control temperature set points and air volumes throughout the building from a central location. Direct digital controls (DDC) utilized by the BAS will function more efficiently than older pneumatic controls and help to avoid unnecessary use of HVAC equipment during non-business hours and holidays.


  • Develop and implement a comprehensive Indoor Air Quality Management Plan using the EPA’s “Indoor Air Quality Building Education and Assessment Model” (I-BEAM).

    • Assign an IAQ manager. This individual should be responsible for developing and managing the IAQ plan including managing contracts for IAQ related services and communication with building occupants about IAQ related issues.
    • Conduct an IAQ audit of the building and grounds to determine IAQ status. Use forms provided by I-BEAM to record the basic conditions of the building’s occupied spaces, mechanical systems, and building exterior.

  • Following the initial audit, the IAQ manager must make periodic inspections to uncover new IAQ issues and monitor the status of previous issues. The I-BEAM tool supplies inspection forms that can be tailored to the project building to facilitate this process.


  • Establish protocols to manage all significant pollutant sources referenced in I-BEAM that are applicable to the project building.


  • Ensure that procedures are in place for receiving and responding to IAQ complaints from building occupants. The I-BEAM tool provides sample forms and logs for fielding and recording occupant complaints as well as information about key principles for developing effective communication with building occupants regarding IAQ issues. Strategies for investigating and resolving the issues that trigger occupant complaints are covered by a variety of I-BEAM guidelines.

  • USGBC

    Excerpted from LEED 2009 for New Construction and Major Renovations

    IEQ Prerequisite 1: Minimum IAQ Performance

    Required

    Intent

    To establish minimum indoor air quality (IAQIndoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors.) performance to enhance indoor air quality in buildings, thus contributing to the comfort and well-being of the occupants.

    Requirements

    CASE 1. Mechanically Ventilated Spaces


    Mechanical ventilation systems must be designed using the ventilation rate procedure as defined by ASHRAE 62.1-2007, or the applicable local code, whichever is more stringent.

    OPTION 1. ASHRAE Standard 62.1-2007 or Non-U.S. Equivalent

    Meet the minimum requirements of Sections 4 through 7 of ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality (with errata but without addenda). Projects outside the U.S. may use a local equivalent to Sections 4 through 7 of ASHRAE Standard 62.1-2007.

    OR

    OPTION 2. CEN Standards EN 15251: 2007 and EN 13779: 2007

    Projects outside the U.S. may earn this prerequisite by meeting the minimum requirements of Annex B of Comité Européen de Normalisation (CEN) Standard EN 15251: 2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics; and the requirements of CEN Standard EN 13779: 2007, Ventilation for nonresidential buildings, Performance requirements for ventilation and room conditioning systems, excluding Section 7.3 – Thermal environment, 7.6 – Acoustic Environment, A.16, and A.17.


    CASE 2. Naturally Ventilated Spaces


    Naturally ventilated buildings must comply with ASHRAE Standard 62.1-2007, Paragraph 5.1 (with errata but without addenda). Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

    Potential Technologies & Strategies

    Design ventilation systems to meet or exceed the minimum outdoor air ventilation rates as described in the ASHRAE standard. Balance the impacts of ventilation rates on energy use and indoor air quality to optimize for energy efficiency and occupant comfort. Use the ASHRAE Standard 62.1-2007 Users Manual (with errata but without addenda1) for detailed guidance on meeting the referenced requirements.

    FOOTNOTES

    1 Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

Technical Guides

IEQ Space Matrix - 2nd Edition

This updated version of the spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated. Up to date, 2nd Edition.


ASHRAE 62.1-2007: Outdoor Airflow Monitoring Devices.

ASHRAE 62.1-2007 should be referenced when designing outdoor airflow monitoring devices.


IEQ Space Matrix - 1st Ed.

This spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated.  This is the 1st edition.

Publications

Greening the Building and the Bottom Line

This Rocky Mountain Institute publication is a case study of the connection between worker productivity and indoor air quality.


Procedural Standards for Testing, Adjusting and Balancing of Environmental Systems, 7th ed. (National Environmental Balancing Bureau, 2005)

This manual provides information on the technology and techniques for the design, operation, servicing, and balancing of environmental systems.

Organizations

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)

ASHRAE publishes widely used standards and publishes the ASHRAE Journal.


Labs for the 21st Century (Labs 21)

Labs21 is a voluntary partnership program dedicated to improving the environmental performance of U.S. laboratories.


Indoor Air Quality Association

IAQA is a nonprofit organization dedicated to promoting the exchange of indoor environmental information through education and research.


Mechanical Service Contractors of America

MSCA is a national trade association that provides educational resources and training programs on sustainable service and maintenance practices for HVACR contractors.


CIBSE Applications Manual 10-2005

Located in London, this organization publishes a series of guides on ventilation, including natural ventilation.

Web Tools

Energy Cost and IAQ Performance

This website contains reports from an extensive EPA modeling study that assessed the compatibilities and trade-offs between energy, indoor air quality, and thermal comfort objectives for HVAC systems and formulated strategies to achieve superior performance.

Software Tools

62MZ Calculator: Ventilation Rate Procedure

This is a Microsoft Excel calculator that accompanies the ASHRAE 62.1 reference standard. The calculator allows users to plug in variables for specific project types and run the Ventilation Rate Procedure.


CONTAM 3.0 Multizone Modeling Software

Public domain software from NIST (National Institute of Standards and Technology) that has natural ventilation sizing tools, and flow models to analytically predict room-by-room airflows.


Loop DA Multizone Modeling Software

Public domain software from NIST (National Institute of Standards and
Technology) that has natural ventilation sizing tools, and flow models
to analytically predict room-by-room airflows.


ASHRAE 62.1 iPhone App

ASHRAE released an app for iPhone, iPod touch, and iPad that allows you to perform comprehensive minimum ventilation calculations for a wide variety of commercial buildings based upon Standard 62.1, using either I-P or SI units. This app is based upon the 62MZCalc.xls. Now, you can make calculations at a meeting and know if your project meets IEQp1 or IEQc2.

Ventilation Rate Table

This example ventilation rate table from 23 High Line provides guidance when developing prerequisite compliance documents for your project.

Air Riser Diagram

This example air riser diagram from 23 High Line shows the mechanical ventilation supply for the building. It is the ducted diagram showing how air will be supplied to building occupants. Use this as an example for how to document ventilation effectiveness compliance.

Mechanical Systems Schedule

Use this example mechanical schedule created from 23 High Line for guidance when developing ventilation effectiveness compliance documents for your project.

LEED Online Forms: NC-2009 IEQ

Sample LEED Online forms for all rating systems and versions are available on the USGBC website.

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

1003 Comments

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Geraldo Pithon
Jan 19 2016
LEEDuser Member

VRP Compliance Calculator or 62MZCalc for projects outside U.S.?

Project Location: Brazil

I am submitting for review a project outside the US, in Brazil.
The legislation of Brazil is very similar to that specified by ASHRAE 62.1. However, at the LEED Online I am instructed to prepare a new worksheet describing the service to credit according to local law, and may not use the VRP Compliance Calculator option or 62MZCalc spreadsheet. Would not it be more appropriate for the analysis team I ever use one of these presentation tools available? What is recommended in this case? Okay to me to continue the service through the VRP Compliance Calculator?

If I can use the VRP Compliance Calculator, should I mark "Is the project located outside of the U.S. and pursuing Option 2 or a local equivalent in Option 1?"

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David Hubka Director - Operations, Transwestern Sustainability Services Feb 11 2016 LEEDuser Expert 2219 Thumbs Up

you are allowed to use the 62MZ calculator, i suggest you use this to document the minimum ventilation requirements are met.

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CATALINA CABALLERO SUSTAINABILITY COORDINATOR JALRW Eng. Group Inc.
Dec 29 2015
LEEDuser Member
4169 Thumbs Up

Existing building with new addition compliance

we have a new addition added to an existing facility. The consultant has decided to pursuit NC for this project, therefore the question comes if there is an existing area within the LEED boundary with existing AC units that wont be modified, do these units need to comply with the minimum OA required as well? Would a Test and Balance be necessary or only plans?

In the case that they take these existing areas out of the LEED boundary, only the new equipment will need to be Tested and Balanced, correct?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Dec 29 2015 Guest 953 Thumbs Up

i.First of all, there are two different concepts here: this prerequisite requires your project to have VENTILATION (natural, mechanical, engineered...) regardless of whether or not you have A/C.

ii.Every occupiable space within your LEED Project Boundary must be ventilated. I am pretty sure your reviewers will require you to demonstrate that.

iii.Regarding your cx1. Commissioning (Cx) is the process of verifying and documenting that a building and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner's project requirements. 2. The process of checking the performance of a building against the owner's goals during design, construction, and occupancy. At a minimum, mechanical and electrical equipment are tested, although much more extensive testing may also be included. question I would ask in the EAp1 forum.

Post a Reply
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CATALINA CABALLERO SUSTAINABILITY COORDINATOR JALRW Eng. Group Inc.
Dec 29 2015
LEEDuser Member
4169 Thumbs Up

Existing building compliance

we have a new addition added to an existing facility. The consultant has decided to pursuit NC for this project, therefore the question comes if there is an existing area within the LEED boundary with existing AC units that wont be modified, do these units need to comply with the minimum OA required as well?

In the case that they take these existing areas out of the LEED boundary, only the new equipment will need to be Tested and Balanced, correct?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Jan 18 2016 Guest 953 Thumbs Up

Every interior space within your LEED Project Boundary must comply with the ventilation requirements.

Regarding the TaB question, I am not pretty sure but I would test the existing equipment to guarantee the outdoor air required by the VRP is provided by your system.

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Joe Sechler BNK
Dec 21 2015
LEEDuser Member
12 Thumbs Up

IEQP1 VRP Calculator saying I'm non-compliant

Project Location: United States

Figured out my question. Please delete

Post a Reply
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Elodie DUMAS ALTO Ingénierie
Dec 21 2015
LEEDuser Member
770 Thumbs Up

Global Compliance Paths EN 15251

Project Location: France

Hi,
There's several quality level for interior air in EN 15251 : category I to III. The reference guide doesn't enjoin a specific category, as you can see in this extract :
"To determine the ventilation rate: Use Table B.1 in Annex B of CEN Standard EN 15251:2007 to find the appropriate percentage of dissatisfied building occupants and select Category I, II, or III based on the building design and applicable local codes."

We hesitate to select the lower category (III). Do you have any feedback about this ?
Thanks

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Elodie DUMAS ALTO Ingénierie Jan 19 2016 LEEDuser Member 770 Thumbs Up

Any idea ?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M Revitaliza Consultores
Dec 16 2015
Guest
953 Thumbs Up

VRP in the space matrix

Hallo,

What does VRP stand for in the column IEQp1 of the space matrix? I've looked it up in the notes and definitions tab but it does not appear.

I do not think it stands for Ventilation Rate Procedure because there are other methodologies appart from that one (CIBSE, natural ventilation...)

Thanks

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Andrey Kuznetsov Green Building and Sustainability Consultant (LEED AP BD+C), Signy Group Feb 11 2016 Guest 138 Thumbs Up

Actually I supposed that it's per 62.1 - the ventilation rate procedure (VRP), the indoor air quality procedure (IAQP), and the natural ventilation procedure (NVP) - see ASHRAE Journal, June 2012, "Minimum Outdoor Airflow Using the IAQ Procedure".

Post a Reply
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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M Revitaliza Consultores
Dec 04 2015
Guest
953 Thumbs Up

Aeronautical Maintenance Workshop

Project Location: Colombia

This is a 70,000 sf Aeronautical Maintenance Workshop in Colombia with the following features:

-The space is 6 meters height.
-There are interior walls 5 meter height. Therefore, all the workshop is connected at the top of the space (1 meter)
-There are plenty of skylights that provide natural ventilation.
-Distances and size of openings meet sections 6.4.1 and 6.4.2 of the Standard ASHRAE 62.1 - 2010.

My question is: can I consider it correctly ventilated considering the openings are at the top of the space? We are going to use ASHRAE 62.1-2010 to demonstrate compliance for the whole workshop.

Thanks in advance.

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Miriam Ramírez Baumgarten ARCH. LEED AP BD+C, ID+C, Revitaliza Consultores Dec 09 2015 Guest 26 Thumbs Up

Our question is if the interior 5m division walls would affect compliance with the prerequisite even though every "cubicle" or confined area is less than 25´(8m) away from the openings (vertically as well as horizontally) Any thoughts?

Thanks!

Miriam

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Ian McCall Environmental Engineer Le Sommer Environnement
Nov 17 2015
LEEDuser Member
995 Thumbs Up

Global Compliance Paths ASHRAE 62.1 & EN 15251 and EN 13779

Project Location: France

Dear All,
The Global compliance Path guide book gives the option between ASHRAE 62.1-2007 or European standards EN 15251: 2007 and EN 13779: 2007.

Question :
Can we use the ventilation rates described in the ASHRAE 62.1 in regularly occupied spacesRegularly occupied spaces are areas where one or more individuals normally spend time (more than one hour per person per day on average) seated or standing as they work, study, or perform other focused activities inside a building. (Table 6.1, 6.2, 6.3) and the extraction rates (e.g. bathrooms) described in the CEN Standards EN 15251: 2007 and EN 13779: 2007 in in non-regularly occupied rooms (bathrooms) and achieve credit compliance?
If the French extraction rate is higher than the CEN / EN standard can it replace them?

Regards,
Ian

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Nov 17 2015 Guest 953 Thumbs Up

Hallo Ian,
I do not think they will accept combining both methodologies unless you have a good reason for doing that, for instance, if you your project has a type of space that is not covered in one of the standards.
My advise is that you should use the ASHRAE calculator because the reviewers are usually not familiar with the CEN standard.

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Devani PERERA Green Building Consultant, ELAN Nov 19 2015 LEEDuser Member 374 Thumbs Up

Hello Ian,
I agree with Gustavo in that GBCI would accept one path or the other and not a mix of it. I have submitted projects using the european standrads and it has been accepted without any problem.
The credi focus is the minimum rates so if your rates are higher on your design it isnt a problem.

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BAOQUY VU Principal R.W. Sullivan Engineering
Nov 06 2015
LEEDuser Member
37 Thumbs Up

Dorm Suite Ventilation

Project Location: United States

Our project is a large high rise dorm consisting of 4-person suites arranged typically as a 2BR and two 1BR's connected by a short inner hallway. The suite has a shared single bathroom accessible from the inner hallway. The inner hallway is very narrow and not occupiable for any duration. Our current scheme includes bathroom exhaust at 50-cfm continuous. Fresh air (neutral, i100% outside air) is delivered at 50-cfm to the hallway only (not each bedroom). The 50-cfm of OA meets the total suite ventilation requirement based on the 5-cfm/person + 0.06 cfm/sf requirement of ASHRAE 62.1-2007. The doors to each bedroom are undercut to allow the fresh air into the bedrooms.

Would the above scheme meet the requirements for mechanical ventilation per ASHRAE 62.1 for all spaces in the dorm suite?

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 06 2015 LEEDuser Expert 3528 Thumbs Up

No, that would not meet the requirements for mechanical ventilation. Mechanical ventilation should have some way of making the air come into the occupiable space.

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Michelle Robinson Re:Vision Architecture Nov 06 2015 LEEDuser Member 1154 Thumbs Up

Any chance the bedrooms have operable windows such that they meet the naturally ventilation requirements in terms of size, while the inner hallway is mechanically ventilated?

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ABDUL MUTHALIB MOHAMED INNOWELL ENGINEERING INTERNATIONAL PVT LTD
Nov 05 2015
LEEDuser Member
174 Thumbs Up

LEED Boundary

Project Location: India

I am working on LEED boundary for Factory building. The factory has two buildings with common car parking but we are applying LEED certification for only building - 1. Moreover, the car parking is near to building - 2 and a bit far away from building - 1. To achieve SSCR 7.2 Heat Island Reduction - Non roof, should i include parking area in LEED boundary?

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 06 2015 LEEDuser Expert 3528 Thumbs Up

You should ask this on the SSc7.2 forum. Tristan may be able to relocate it for you.

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M Revitaliza Consultores
Nov 05 2015
Guest
953 Thumbs Up

Hangar

Project Location: Colombia

My project is a 93,000 sf open-plan hangar. We are designing grills on walls that count for 4% of the floor area on 2 opposite facades to induce crossed-ventilation. Has anyone tried this strategy successfully in a project before?

My concern is that it is a big space and I am afraid the reviewer will ask for mechanical ventilation.

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 06 2015 LEEDuser Expert 3528 Thumbs Up

For natural ventilation, all occupiable space should be within 25' of an opening. If you do not meet this, then I would recommend adding exhaust fans to draw the ventilation air through the openings. You are allowed to control this based on CO2Carbon dioxide levels in the space.

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Joseph Snider, AIA, LEED Fellow LEED Architect, SEQUIL Systems, Inc. Nov 06 2015 LEEDuser Member 369 Thumbs Up

As Andrew has noted, if any part of the space is further than 25' (8 m) away from those openings, the LEED reviewers will have a questions. We have used a similar strategy on large warehouse and manufacturing spaces in multiple LEED projects in Colombia and Venezula. In those cases though, there was a ridge vent in addition to the side wall louvered openings. This works as a stack event and air comes in the sides and is exhausted out the top. These can even be mechanical exhaust fans for not too much cost. When the fans were passive and not mechanical, we had to provide documentation of an engineered natural ventilation system showing how the air would move through the space and how that was more than enough air than required by ASRHAE.

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Nov 11 2015 Guest 953 Thumbs Up

Thanks for your comments,

If I could use Section 6.4.1.2. of ASHRAE 62.-2010 I would be able to comply with natural ventilation. Can I use 2010 version instead of section 6.4 - ASHRAE 62.1-2007?

"6.4.1.2. Double side openings. For spaces with operable openings on two opposite sides of the space, the maximum distance from the operable openings is 5H, where H is the ceiling height"

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Annalise Reichert LEED Project Coordinator, Environmental Building Strategies Dec 15 2015 LEEDuser Member 251 Thumbs Up

I am working on a similar project, a 45,000 sf warehouse that is part of an Electrical Training Facility to train electrical contractors. The warehouse is primarily used for storage of educational materials, however a small section (about 2,000 sf) is used for an hour long training session 3 times per week. The facility manager considers this space unoccupied.

The warehouse perimeter wall has large roll-up doors that are manually opened in the morning, and manually closed at night. 3 large rooftop exhaust fans run continuously throughout the building's hours of operation.

To demonstrate that the unoccupied space meets ASHRAE 62.1 minimum ventilation rates, I am using the engineered natural ventilation approach to show the exhaust fans induce outside air from the doors throughout the warehouse space. My question is, do the roll-up doors need to have automatic controls, or is manually opening them acceptable? Additionally, do the rooftop exhaust fans need any sort of control or is it adequate that they turn on and off based on the facility operating schedule?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Dec 21 2015 Guest 953 Thumbs Up

1. According to LEED definition of regularly occupied space I think your warehouse cannot be considered as unoccupied.
2.In the VRP calculator you should use peak occupancy (but you should also consider the diversity factor)
3.Taking into account this is an engineered system, I think there is no specific requirement for the controllability of the roll-up doors. The outdoor air will enter the building through cracks and gaps in the envelope.
4.Based in my experience, I have never been asked to provide a minimum control or schedule, but it needs to be properly commissioned and meet the OPROwner's project requirements (OPR) is a written document that details the ideas, concepts, and criteria that are determined by the owner to be important to the success of the project..

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William Beechinor Engineer 1 AlfaTech
Nov 04 2015
Guest
8 Thumbs Up

Calculating Ds for LEED 62MZCalc

Project Location: United States

Hello,

I am currently trying to calculated Ds for the cooling condition for a project I an working on. Initially, I had the Ds value for each dual fan duct duct VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. unit set to 100%, but I was told by a colleague to change the value of Ds to be Ds = the minimum cooling flowrate of VAV/ the maximum cooling flowrate (Vdzd) of VAV.

For example a room in the building has a max supply cfm of 210 and a minimum supply cfm of 63. Should Ds then be: Ds=63/210 = 30%? Or should I leave Ds as 100%?

When I switched Ds from 100% to the equation I got the critical zone needs more ventialation error message.

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Omar ElRawy Building Engineer, LEED AP BD+C, EA Building Consultants Nov 05 2015 Guest 977 Thumbs Up

A direct answer to your question is: set Ds = minimum flow (30%).

I had a technical advice by the reviewer before to perform the calculations at the worst-case conditions, which was (in my case) to set most VAVs at Ds of 30%, and few VAVs that where designed with Ds of 40% (and I justified that by a narrative).
Also the worst-case case is generally during heating mode, for me, I like to check both; heating and cooling modes.

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William Beechinor Engineer 1 AlfaTech
Nov 03 2015
Guest
8 Thumbs Up

Calculating Ds for cooling condition

Project Location: United States

Hello,

I am trying to determine whether or not I am calculating Ds correctly. I previously had every zone set to 100% Ds, but I was told that Ds = the minimum supply air flowrate/maximum supply air flowrate. For example we are using dual fan dual duct VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. units and the maximum cooling cfm for a room is 210 cfm and the minimum is 63 cfm. Should Ds then be:
Ds = 63/210 = 30%? Or should I just have Ds set to 100%?

When I had all the values to Ds set to 100% the sheet worked, but when I changed it to the equation I got the error message Critical zone needs more ventilation. Any help would be greatly appreciated.

Thank you for your time,

William Beechinor

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Logan Dorrell Sr. Mechanical Engineer AECOM
Nov 03 2015
LEEDuser Member
33 Thumbs Up

How do we show for compliance for non-occupiable spaces?

Project Location: United States

I'm a little confused by what we are supposed to show to document compliance for non-occupiable spaces, like restrooms, that the space matrix call out as "N (VRP) / Y (other req's).

We have filled out the VRP calculator for all the spaces and have ventilation thru 100% DOAS serving all the spaces with radiant panels for heating. However, the LEED reviewer is questioning our square footage because the SF in the VRP Calculator is less than the total project square footage because the non-occupiable spaces are not included, since the space matrix said not to include them in the VRP Calcs.

We have enough exhaust in these spaces to comply with ASHRAE 62.1, but what does LEED want us to show for these spaces to prove compliance? Does checking the box that says, "The project meets Sections 4 through 7 of ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air
Quality." qualify us as stating that we meet the ventilation rates for these spaces or do we need to prove it further to LEED?

Should we just submit a floor plan with the non-occupiable zones highlighted and with square footages shown or do we need to submit some kind of offline spreadsheet for these zones?

Thank you,

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 03 2015 LEEDuser Expert 3528 Thumbs Up

I always upload a sheet showing every space type that is not included in the VRP calc and the associated areas. Some are exhaust only, some are non-occupiable, and some are not applicable such as chase space and shafts. If you add it all up then you should be somewhere around 90% of the gross area from PIf3.

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SAMY Chamy Enginneer T&T Green
Nov 02 2015
Guest
155 Thumbs Up

Exhaust Requirement

Project Location: Afghanistan

I think this credit is for fresh air requirement.

Is there any requirement for Exhaust rates, are they need to documented for this credit

Our project have store rooms as per local Fire and safety compliance no electrical circuits and equipment's are allowed to this rooms

so can we exclude this kind of spaces from VRP calculation

VRP calculation is for Occupied area or all areas (Toilet, Storerooms)

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 02 2015 LEEDuser Expert 3528 Thumbs Up

The VRP calculation is for occupiable spaces. However, the credit applies to all requirements of ASHRAE 62.1 - 2007, including exhaust rates.

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kevin connolly
Oct 28 2015
Guest
4 Thumbs Up

Alternative Compliance in lieu of LEED Tables

Has anyone been successful using the alternative compliance path and submitting their own ASHRAE 62.1 calculation/spreadsheets in lieu of using the built in LEED or 62MZCalc form?

We would rather save time by not re-entering a ton of info and just provide a narrative and our calcs to prove we meet ASHRAE 62.1.

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David Hubka Director - Operations, Transwestern Sustainability Services Oct 31 2015 LEEDuser Expert 2219 Thumbs Up

While we have not submitted our own EQp1 calculations in lieu of the 62MZ we have been told by GBCI that non-62MZ calculations are acceptable.

As always, provide a detailed narrative explaining your methodology.

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 02 2015 LEEDuser Expert 3528 Thumbs Up

I think that it is unlikely that the LEED reviewer will accept your own spreadsheet. They provide a spreadsheet for you to use. I think it would take longer for you to convince them that you calculated multiple zones with unused OA correctly than it would to just fill out their spreadsheet. I recommend using the provided 62MZcalc.

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SUMAC Inc. SUMAC
Oct 27 2015
Guest
176 Thumbs Up

source of air for mechanical Ventilation

Project Location: Peru

We have a project that is natural ventilated in perimeter spaces (circulations and cafe dining rooms), and It is mechanical ventilated in core spaces (meeting rooms and cafe dining room) that is pursuing LEED for NC 2009.
Our mechanical designer is wondering if the source of supply outdoor air can be an indoor natural ventilated space. What I mean is that we can locate the supply duct for the injector fan near to the operable window in the indoors?

Any help, please?

Thanks you!

Dante Garcia
LEED AP BD+C

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Oct 27 2015 LEEDuser Expert 3528 Thumbs Up

No, you cannot. The fresh air needs to come from outside.

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O Moltay
Oct 19 2015
Guest
9 Thumbs Up

v2009v4_Minimum IAQ Performance Calculator_v02 - Any Experience?

Dear Members,

Do you any experience with the v2009v4_Minimum IAQIndoor air quality: The quality and attributes of indoor air affecting the health and comfort building occupants. IAQ encompasses available fresh air, contaminant levels, acoustics and noise levels, lighting quality, and other factors. Performance Calculator_v02 spreadsheet found under Credit Resources for IEQp1? Is this form suitable for showing compliance with Multiple Zone Systems in lieu of ASHRAE 62MZ calc spreadsheet?

Additionally, we are confused by some of the parameters when using the Appendix A method for VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. systems. When there is no secondary recirculation, shouldn't Er and Ep be "1"? However, the definition of Ep is given as Vpz / Vdz, in which case Vpz = Ds * Vdz for VAV systems representing minimum flow conditions. Therefore, shouldn't Ep be equivalent to Ds?

Thank you,

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Joseph Snider, AIA, LEED Fellow LEED Architect, SEQUIL Systems, Inc. Oct 19 2015 LEEDuser Member 369 Thumbs Up

We recently had the opportunity to get some feedback from a USGBC reviewer on the new spreadsheet. Yes, this is the preferred calculator, instead of the older ASHRAE 62mz excel sheet and the template. This appears to be what they want to see going forward as it is better organized and the results tab makes it easier to review.

Note one item we found which is that on the SINGLE ZONE tab, the default occupancy isn't populating correctly. It pulls numbers from the wrong place. So you need to use manually entered occupancies. Apparently this is a known error and they are working on fixing it and re-releasing it.

I'll default to some of the more technical experts on the second part of your question.

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O Moltay Oct 27 2015 Guest 9 Thumbs Up

Yes, the single zone tab does not populate correctly. Additionally, the summary tab fails to display all input systems in our case. We contacted the GBCI about this and they said that they did not know of this mistake before and that it is probably due to the fact we have gone back and forth in inputting multiple zone and %100 OA systems. So be careful when using this spreadsheet.

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Jian Hui Liu Oct 28 2015 Guest 55 Thumbs Up

My project is outside of the US.Can't i use the spreadsheet?

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Jutta Berns-Mumbi principal ecocentric cc
Oct 09 2015
LEEDuser Member
1841 Thumbs Up

Engineered natural ventilation system

Project Location: South Africa

Hi all

We have three Warehouse's that use 'turbo ventilators' (wind driven extraction fans) and not a pure mechanical system. The warehouses also do not have enough enough openings to meet the natural ventilation requirements of 5.1 in ASHRAE 62.1.

To meet the requirements of IEQp1 I feel my only option is to motivate that the this is an 'Engineered natural ventilation system' as per the exception to 5.1 in ASHRAE 62.1. In the wording (and confirmed in CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide ID#2539);

'An engineered natural ventilation system when approved by the authority having jurisdiction need not meet the requirements of Sections 5.1.1 and 5.1.2. '

South African building codes don't deal with turbo ventilators directly, and because warehouses do not have a minimum ventilation requirement here the designs/drawings were approved by the authority having jurisdiction (AHJ).

The issue is they would definitely be approved by AHJ because there is no minimum requirement.
But this is like simply using a less stringent code, which is not the intent.

How can I show compliance with IEQp1 for these areas?

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Oct 09 2015 Guest 953 Thumbs Up

Does the cut-sheet show estimated cfm under normal conditions? Then, you might be able to complete the calculator and meet the minimum requirement.

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Joseph Snider, AIA, LEED Fellow LEED Architect, SEQUIL Systems, Inc. Oct 19 2015 LEEDuser Member 369 Thumbs Up

We have used these types of systems in Colombia in similar warehouse applications. The walls also had louvers on them for intake. We provided basically an engineered natural ventilation analysis to show the projected air flow through the spaces, and compare it to the required amount by ASHRAE. Usually these systems, especially if there are openings on the side, bring in more than enough outdoor air.

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Jutta Berns-Mumbi principal , ecocentric cc Oct 27 2015 LEEDuser Member 1841 Thumbs Up

Thanks for the responses. Sorry I took so long to reply.

Gustavo yes the cut-sheets show estimated cfm. But this is of course at an assumed wind speed over the roof.

Joseph was this approach accepted?

So in summary my approach would be to provide analysis that shows the ASHRAE 62.1 requirements are met rather than approved by AHJ because there is no requirement here.

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FABIO VIERO Head of Sustainability Manens-Tifs s.p.a.
Oct 05 2015
LEEDuser Member
1087 Thumbs Up

A single big space which include several functions.

Project Location: Italy

Hi All,

I'm now working on a project under LEED NC certification.
The ground floor includes a conference room, offices, technical spaces, meeting rooms, and one big space, in which the following functions are located without any physical separations:
- Two lobbies with reception desk
- Corridors and circulation
- Break area
- Cafeteria
The above-mentioned big space is served by 2 AHUs (which serve also other rooms).
We pursue the verification according to ASHRAE 62.1:2007 and I'd like to understand which kind of space use we have to verify for this big space.
Can we separate in different singles functional units, even if these are not physically separated?

Thanks.

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Nov 02 2015 LEEDuser Expert 3528 Thumbs Up

I would separate it into different spaces based on use. Upload a floor plan showing how the spaces are separated and what the area of each space is.

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VEL MUTHU
Sep 16 2015
Guest
54 Thumbs Up

Working with IEQ P1.

Hello everyone,

I am currently working on a project which has a design requirement on air side system and water side system. When I tried to enter the details into the LEED online form, I got some confusion which I am listing out here. I require your suggestion or support to make my understanding clear to fill the form. The project is located in Dubai.
The HVAC scheme is that, there are ERU’s, DX units, AHU’s, FCU’s in this project and the scheme is ERU’s will supply the fresh air after energy recovered from the return air. This fresh air will be supplied to all the AHU’s and FCU’s catering different part of the building. While I fill the IEQ P1 form, I came across a number of questions which are listed below.

1. Is it enough to provide the details of ERU’s only in the form or I need to input each and every FCU’S and AHU’S in the form. I believe, I need to input all the FCU’s and AHU’s in the form after categorising them into Single zone and multiple zone units.
2. I believe, single zone system is a system serving a single zone only. Multiple zone system is a system which serves a group of zones.
3. In my project, we have single zone and multiple zone FCU’s and AHU’s. while I enter the IEQ P1, I need to check the single zone and multi zone tick box and enter the details of single zone and multi zone units as required irrespective FCU’s or AHU’s. Am I correct?
4. Those with multi zone AHU’s and FCU’s, the return air is taken back to the AHU’s and FCU’s respectively which will get mixed with the fresh air and will be supplied to each zone. I believe this cannot be considered as a local recirculation units and is not a fan power box unit. So there is no need to use 62MZCalc sheet. I can fill the details of these systems/units directly into the IEQ P1 LEED online sheet in the table provided for MULTIPLE ZONE SYSTEM under Appendix for VRP calculator i.e. Table IEQp1-A1 and Table IEQp1 – A2.
5. Space matric for IEQ says, spaces like electrical and mechanical rooms, restrooms and bathrooms are excluded. Is it ok to exclude these rooms from the IEQ P1 online sheet too i.e. excluding these rooms in the form?
Thanks
Vel

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Sep 16 2015 Guest 953 Thumbs Up

1.You have to provide a calculation per each outdoor injection fan (either AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork., ERU...). If this fan serves one single zone (i.e. room) the reviewers are asking to use the online form. Otherwise, use the offline calculator and upload it. You will have to add up the supply air for all the FCU in every zone and the numbers should be consistent with the mechanical schedule.
2.Right
3.See comment #1
4.There are two critical numbers in the calculator: i. outdoor air entering the building (not return), and ii. Supply air (sum of airflow provided by all the FCU in the zone)
5.I would rather check the definition of "occupiable space: an enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only occupied occasionally and for short periods of time." (verbatim from INTERPRETATION IC 62.1-2007-16).

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VEL MUTHU Sep 29 2015 Guest 54 Thumbs Up

Many Thanks Gustavo.

Also,

1. Is it ok to use the Online form itself for Multi zone units or it is mandatory to use the 62MZCALC for these Multi zone units?
2. Electro - Mechanical rooms are not regularly occupied rooms so I can leave these rooms from entering it into the Online form correct?

Thanks

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Sep 29 2015 Guest 953 Thumbs Up

1.The reviewers we have dealt with have always asked us to upload the offline calculator.
2.Imho I think electro-mechanical rooms fall under "equipment rooms" category and according to the interpretation IC 62.1-2007-16 they are exempt from ventilation. Keep in mind that some utility providers recommend installing louvered doors, which I think is a best practice to prevent moisture from accumulating in the room.

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Emmanuel Pauwels Owner Green Living Projects s.l.
Sep 15 2015
LEEDuser Member
3375 Thumbs Up

System type

If a space is ventilated through an exhaust fan (rate according VRP) and a permanently open vent to the outdoors, can this space be considered mechanically ventilated, 100%OA and can use an Ez of 0,8 if exhaust fan is in the opposite side of the room of the vent?

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Sep 15 2015 LEEDuser Expert 3528 Thumbs Up

According to Table 6-2, the above would be correct.

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Emmanuel Pauwels Owner, Green Living Projects s.l. Sep 15 2015 LEEDuser Member 3375 Thumbs Up

Thank you Andrew for the quick answer. I had this doubt because from some previous comments seemed that outdoor air should be provided by a supply system in order to consider the zone as mechanically ventilated.

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Sep 15 2015 Guest 953 Thumbs Up

Hi Andrew,

1.Is the project allowed to have operable windows instead of permanently opened vents? Air would infiltrate through cracks and doors.

2.The project will not be capable of providing MERV13 filters. Is the project still eligible to pursue credit IEQc5?

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Sep 15 2015 LEEDuser Expert 3528 Thumbs Up

1. No, unless they are interlocked to automatically open when the fan is on.

2. No.

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Gustavo De las Heras Izquierdo Arch. Eng. LEED AP BD+C; O+M, Revitaliza Consultores Sep 16 2015 Guest 953 Thumbs Up

1.Is this requirement based in a LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. or addenda? This would be very helpful in order to explain the client.
2.I agree.

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Hieu Huynh Environmental Engineer, LEED AP BD+C
Aug 27 2015
Guest
124 Thumbs Up

62MZ calc for critical zones

Project Location: Vietnam

Hi, my project has PAU to supply OA through VAVs to AHUs, which then supply air to office spaces. This PAU also supplies OA through CAVs to lift lobbies and FCUs recirculate the air there. I plan to submit offline calculator 62MZ calc on LEEDonline. I see "it is acceptable to provide value only for critical zone" and "the critical zone is the zone requires the largest fraction of OA in the primary air stream". So I want to ask that I just need calc OA in office only in the calculator and can neglect the lift lobby?

Thank you very much

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FABIO VIERO Head of Sustainability Manens-Tifs s.p.a.
Aug 21 2015
LEEDuser Member
1087 Thumbs Up

Ventilation for parking garage

Project Location: Italy

Hi All,

I have a question about a project under LEED certification.

We are designing the ventilation of one floor below-grade parking garage, situated below an open area adjacent to an office building.

The garage floor plan is of rectangular shape.

There are no Full Time Equivalent in the parking garage (guard stations, and/or other occupied/occupiable spaces are not located in the garage, so the whole space is only for the purpose of parking and circulation).
There is no mechanical ventilation. Openings for natural ventilation are provided.
We would like to understand whether our design can be considered an alternative compliance path to ensure indoor air quality compliant with "Minimum Exhaust Rate" Table 6-4 of ASHRAE 62.1:2007 Note C " Exhaust not required if two or more sides comprise walls that are at least 50% open to outside".

Openings for natural ventilation are evenly distributed on the roof of the garage (grade level). The overall surface of these openings to the outside is greater than 50% of the overall surface of two side walls.

Also, an electronic CO monitoring system provides an alarm if the threshold of CO concentration achieves/exceeds 25ppm. As a result of an alarm, access to other vehicles to the garage is temporarily impeded until dilution/exhaust of contaminant through natural ventilation lowers CO concentration below the threshold.
Can we implement such a compliance path in lieu of mechanical ventilation?

Thank you

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Aug 21 2015 LEEDuser Expert 3528 Thumbs Up

Hi Fabio, unfortunately, your design does not comply with the requirements of ASHRAE 62.1. The reason that they specify two sides with more than 50% rather than 25% wall area, is because they count on crosswinds ventilating the space. You should add the mechanical ventilation.

Also, in my opinion, relying on buoyancy of CO vs air to ventilate the space is not a good design practice. The level of CO may rise to unsafe levels and it is unlikely that the people going in to get their cars will decide to wait it out. If that case were to happen during a busy period, I could not imagine an owner who would prefer a closed garage in lieu of having simply installed the mechanical ventilation in the first place.

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FABIO VIERO Head of Sustainability, Manens-Tifs s.p.a. Aug 31 2015 LEEDuser Member 1087 Thumbs Up

Thank you so much!

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Mehdi Kardehi Mechanical Engineer Hyder Consulting
Aug 19 2015
Guest
55 Thumbs Up

Are we allowed to used our own developed excel sheets?

Hi All,
A quick question.

Are we allowed to submit our own calculation spreadsheets of ASHRAE 62.1 or we have to use LEED provided forms to apply for this credit?

Cheers,
Medi

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Andrew Mitchell, P.E. Principal, Mitchell Gulledge Engineering, Inc. Aug 20 2015 LEEDuser Expert 3528 Thumbs Up

You will need to use the credit form or the 62MZ calculation spreadsheet found in credit resources.

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Mehdi Kardehi Mechanical Engineer, Hyder Consulting Aug 22 2015 Guest 55 Thumbs Up

Thanks mate:)

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Carl Karlen Sustainability Lead / Associate Architect Cannon Design
Aug 11 2015
Guest
29 Thumbs Up

Natatorium Locker Rooms

Project Location: United States

I am filing out the LEED documentation for IAQc1 for a RecA Renewable Energy Certificate (REC) is a certificate representing proof that a given unit of electricity was generated from a renewable energy source such as solar or wind. These certificates are able to be sold, traded, or bartered as environmental commodities, where an electricity consumer can buy the renewable energy attributes of electricty to support renewable energy, even if they are consuming generic grid-supplied electricity that may be supplied by nonrenewable sources. Center in St. Louis, MO. There is a Natatorium in this Rec with attached Locker/restroom/shower spaces. We are exhausting these space per 62.1 Table 4. How do I document these space for LEED? Is simply showing the EA calculations per 62.1 are correct enough or do I actually need to include these space in my "Minimum IAQ Performance Calculator" (from LEED)?

I am using LEED v2009.

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Todd Tewksbury Mechanical Engineer Bala Consulting Engineers, Inc
Jul 27 2015
Guest
11 Thumbs Up

Low System Ventilation Efffiency for Corridors

Hi,

I am conducting a ventilation calculation for the an office building that consists of open office space, conference rooms, corridors, etc. The office space is served by 4-pipe fan coil (terminal) units. 100% outdoor air provided from a central outdoor air unit is ducted to the return duct of each fan coil unit.

One of my zones (i.e. group of spaces serve by a since fan coil unit) consists of a 700 SF conference room and an adjacent 100 SF corridor.

The conference room has 10 chairs, so at 0.06 CFM/SF and 5 CFM/person, we get about 92 CFM OA. The air distribution effectiveness is 0.8, so the OA requirement is 115 OA CFM.

The 100 SF corridor in this zone has very little internal load - it is an internal space and only a lighting load. The 0.06 CFM/SF required by code, along with its distribution effectiveness of 0.8, requires 7.5 CFM of OA be delivered to this space.

However, since the 7.5 CFM of OA is nearly half of the primary airflow required to cool the space (as calculated by Carrier Hourly Analysis), we're getting a System Ventilation Efficiency as low as 0.20, which is driving up the OA required to the fan coil unit to a point that it is greater than the supply air requirement to cool the zone. For a zone that requires only 400 CFM of 55F supply air for cooling, the OA calculation is requiring (115 CFM + 7.5 CFM)/0.20 = 612.5 CFM of OA. The ASHRAE 62.1 Calc is increasing the supply air to this zone such that it is 100% OA and it is overcooling the space, which requires reheat. This is detrimental to the buildings energy performance because the increase OA conditioning load and zone reheat are unnecessary.

I understand that I can manually change airflow in HAP and alter the model in other ways to get a more logical answer, but I am really looking for a LEED interpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. towards whether or not this small corridor (an other small spaces that require OA by ASHRAE 62.1) really need to be included in the OA calculation in such a situation. My firm would like to use our energy modeling software to calculate loads and OA requirements for buildings, but this specific instance is preventing us from doing so.

Please let me know if you have any knowledge as to whether these small spaces requiring OA can be excluded/altered from the IEQp1 Calculation in any way. Any help in a resolution is much appreciated. Thanks!

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Ilona Johnson, PE, CEM, LEED AP Associate, Lilker EMO Energy Solutions Jul 27 2015 Guest 474 Thumbs Up

Todd,
LEED reviewers will definitely expect you to ventilate the corridor properly. Some options for you include:
- increase the supply air to the corridor
-if the corridor is in the building interior and does not need heat, then you could design it without reheat. This would allow you to use an air distribution effectiveness of 1.0. That should help a little bit.
-you could install a transfer fan from another room to the corridor. Just note that your calculation would have to be based on "unused outdoor air".
I hope that helps!
ilona

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Jutta Berns-Mumbi principal ecocentric cc
Jul 20 2015
LEEDuser Member
1841 Thumbs Up

Cold rooms

Project Location: South Africa

Good morning,

We have a project that has two cold rooms at -17 and 0 degrees Fahrenheit. These rooms are temporary storage locations of perishable product.
They will be regularly occupied but only for short shifts (around half an hour).

These cold rooms (as with most cold rooms) do not have a fresh air supply to them. It would not be practical to supply fresh air to them, as this would result in huge energy uses and a much more expensive system. The rooms are very large, will frequently have doors opened and closed, and are only occupied by a few occupants
I can find no reference anywhere in ASHRAE 62.1 regarding cold rooms.

Is there anyway in which I can exclude these rooms from the requirements of ASHRAE 62.1 for IEQp1?
I can find no other interpretation result speaking to this.

Also the cold rooms are acceptable according to the local code.

Thank you

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