This credit requires compliance with a varied group of items that cumulatively help keep pollutants out of the indoor air. These requirements include self-closing doors on janitors' closets, MERVMinimum efficiency reporting value. 13 filtration on mechanical equipment, and entryway trackoff systems.
Compliance will require the coordination of team members—including the mechanical engineer, architect, plumbing engineer, and contractor—and also impact project design and operations. The basic requirements are:
In addition to tobacco smoke, covered in IEQp2, one of the greatest sources of indoor pollutants is the dirt and other contaminants brought into buildings on people’s shoes. This material is tracked through the building interior, increasing the need and frequency for cleaning, and the wear on interior finishes. Dust can also be introduced into ventilation systems and distributed throughout a building, negatively effecting indoor air quality.
While it takes a lot of coordination to meet the many credit requirements, this is generally a low-cost credit. The most significant impact may come if MERVMinimum efficiency reporting value. 13-compatible air-handling equipment is not initially specified, as redesigning mechanical systems can be costly. In some situations, especially when using heat pumps, HVAC systems cannot accept MERV 13 filters because they are not able to draw air through such a thick filter.
MERV 13 filtration results in an energy-use trade-off. While MERV 13 filters offer a greater level of air filtration and, consequently, increased indoor air quality, they also increase resistance to airflow and fan energy loads. If you can separate space conditioning from ventilation and use radiant systems for all or most of the space conditioning, you can minimize this energy penalty.
Multifamily residential and hotel projects may have difficulty achieving this credit due to the MERVMinimum efficiency reporting value. 13 filtration requirement. These projects often do not have base-building HVAC systems; they use PTACs instead, which generally cannot be fitted with MERV 13 filters. If a project has forced air systems and MERV-13 filtration is not used, then you cannot pursue or achieve this credit. Naturally ventilated buildings do not have to meet the MERV 13 filtration requirement, as air filtration will not be part of system design.
When LEED 2009 was launched, this credit included language calling for containment drains in laboratory spaces where chemicals are mixed. However, the requirement was vague and it wasn't clear how to document it. Fortunately, in the July 2010 LEED addenda issued by USGBC, this requirement was removed.
There is no definitive information from USGBC on this one way or another. It is recommended that project teams do their best to find low-emitting options for IEQc5, and that IEQc4.3 compliance is recommended.
However, LEEDuser has heard that project teams have had success not including track-off mats, such as the type with grilles and small strips of carpeting. Also, mats that are removed for cleaning are not permanently installed and thus not subject to credit requirements. If used as track-off surfaces, carpet tiles should be certified, however, and are available with the requisite certifications.
There is not an official glossary definition that LEEDuser is aware of. However, various references indicate that LEED views "high volume" as one or more printers in an area totaling more than 40,000 copies (20,000 double sided) per month. The number is based on "expected" use, not capacity. This definition can be found in 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. #1938 issued 1/7/2008, for example, and although that Interpretation is not applicable to LEED 2009, the number 40,000 has appeared in enough places that we view it as a solid number.
If the copiers print less than 40,000 pages/month (20,000 pages double-sided) you do not need to install dedicated exhaust, self-closing doors and deck-to-deck partitions. Additionally, if you use printers that do not emit VOC’s or other harmful contaminants into the indoor environment, you can make a case for exemption.
LEED Interpretation #10098, dated 8/1/2011, states that "The intent for the entryway system (grilles, grates, walk-off mats) is to capture dirt and dust. An exception to the 10 foot length and/or indoor location is acceptable provided your alternative solution meets this intent and is thoroughly justified."
Project teams have been successful including exterior mats that are protected from the weather and regularly cleaned. LEEDuser has not heard of a project successfully gaining an exception to the 10-foot requirement, however. In situations where an irregular shaped mat makes sense, teams should consider whether people entering the building will travel at least 10 feet over a mat, and not be able to short-circuit it. A short narrative explaining the impediments and how your solution meets the standard established by the LEED Interpretation is recommended.
These entrances are those that are used by building occupants on a regular basis. If your project has unique circumstances where certain building entrances are not regularly used or do not serve building occupants, they may be excluded. For example, emergency exits that are not used as regular entrances can often be excluded.
LEED Interpretation #5266 made on 05/30/2007 states that the requirements are applicable only to entrances from the outdoors.
Yes, carpet tile applies per LEED Interpretation Ruling #10252. Some project teams have preferred to use carpet tile due to ease of maintenance and avoidance of trip hazards. The carpet tile must be specifically designed for entryway systems. Regular carpeting that is not designed for this purpose and does not have regular cleaning is not applicable.
LEEDuser has not seen an official ruling on this, but our expert consensus is no.
One, replacing a physical control with a policy control is a bit of a downgrade. Two, 100% avoidance of hazardous chemicals in cleaning is unlikely. The green cleaning purchasing credit in EBOM, for example, considers 30% good enough to earn the credit. Also, the thresholds, categories, and standards referenced in that credit will only go so far in preventing use of any cleaning supplies that might generate gases or chemicals that should be exhausted.
Identify programming requirements for special-use spaces such as high-volume copy rooms (40,000 pages or more per month), laboratories, art rooms, chemical storage, housekeeping areas, and other spaces that may expose occupants to hazardous materials.
Identify space requirements for entryway walk-off mats. Review the impact that the required ten-foot entryway systems will have on common areas, lobbies, and other interior spaces adjacent to building entries. Remember that the entryway systems have to be installed at all regularly used entrances from exterior spaces, including entrances from a covered parking garage into the building.
The LEED Reference Guide states that entryway systems need to be on the interior of the building or in an interior vestibule. It is recommended that projects pursuing this credit with the intent of using an exterior entryway system (either permanent or rollout) consult the GBCI or your certification board via email to verify credit compliance. It is usually accepted that exterior walk-off systems are allowed if they are properly sheltered from weather; that would typically mean some kind of roof, but additional shelter may be warranted depending on local conditions.
Review the potential for using MERV 13 filtration on ventilation systems. Systems with low fan power or filtration size limits may not be able to accommodate MERV 13 filters. Also, many residential and hotel projects use PTACs, or similar packaged systems, which cannot accommodate MERV 13 filters. Any mechanical ventilation must be designed with MERV 13 filters in mind.
If you can use radiant heating and cooling for space conditioning and separate that function from ventilation, you’ll be moving a lot less air and meeting the MERV 13 requirement won’t be nearly as big a deal, due to fewer and smaller ducts and filters.
Include mechanical engineers and design consultants for special-use spaces such as science labs early in the design process.
This is usually a low-cost credit. However, the MERV 13 filtration requirement can increase operational costs for added energy use and more frequent filter changes. If your ventilation system is not typically sized to accommodate a MERV 13 filter, you may have to choose a new system or have one custom-designed, which can add cost. Customization may include resizing ductwork, increasing fan capacity to maintain air delivery despite the added resistance of MERV 13 filtration, or other modifications to system design.
Design an adequate space for ten-foot entryway systems at all regularly accessed building entries. Evaluate all other building entrances—such as employee and service doors—for regular use, which may require entryway systems or roll-out mats.
Determine the type of entryway system that's best for your project. If you install permanent grates, grilles, or slotted entry systems, you will not be required to have a plan for cleaning, although those systems will still need periodic cleaning (less frequently than roll-off mats). However, if you decide to use rollout mats, you'll need to have a contract in place for weekly cleaning. The contract for weekly cleaning can be incorporated into any existing contract but must be clearly spelled out.
While roll-off mats are acceptable, additional documentation (service contracts and schedules) is required to confirm that the mats will be cleaned on a weekly basis. They cost more up-front, but permanent entryway systems provide better performance, require less maintenance, and are easier to document for LEED compliance.
Entryway systems should be climate-specific. For example, regions with high rainfall may choose high void-volume mats—for trapping dirt below the mat surface and fast drying. In regions where mud and snow are a greater source of contaminants, open-loop entry mats may be more appropriate.
Design in space for additional ductwork that might be needed to provide designated exhaust for all garages, high-volume copy rooms, janitors’ closets, science labs, workshops, art rooms, or any other spaces that may be used for mixing and storage of chemicals or hazardous materials. You need to design the exhaust system so that each space with hazardous material has negative pressure in respect to adjacent spaces. For each of these spaces, be sure to include self-closing doors, and deck-to-deck partitions or hard-lid ceilings.
Strategies for space planning may include:
When planning for space allocation to meet credit requirements, consider strategies like merging exhaust systems into a single, main, designated exhaust, or stacking chemical use areas over each other on different floors to minimize ductwork.
Provide adequate space for storage and containment of hazardous liquids.
Hazardous storage containers should be located in a secure area outdoors and away from air intakes.
Develop an outline of all the IEQc5 requirements that apply to your project, and confirm that the schematic design accommodates each one.
Adding ductwork to meet credit requirements can add costs; incorporate space-planning strategies to minimize this issue.
Once programming and space allocations have been determined, confirm that each of the relevant credit requirements is met, as detailed below.
Confirm that all mechanical ventilation systems can accommodate MERV 13 filtration on outdoor and make-up air supply.
If roll-out mats are used, make selections appropriate to the climate. The following specifics are also recommended in the LEED Reference Guide:
Confirm that chemical disposal areas meet local codes for separate drain lines or containment drains.
Confirm that all chemical storage areas, high-volume copy rooms, etc. have:
Locate hazardous waste storage containers away from outdoor air intakes.
Develop all required documentation for LEED submittal, including floor plans indicating locations and lengths of entryway systems, wall details (for deck-to-deck partitions), mechanical drawings showing locations of designated exhaust systems, and mechanical schedules specifying MERV 13 filtration.
For all spaces that may contain hazardous gas (such as garages, janitors' closets, and labs), calculate exhaust rates to confirm adequate negative pressurization. The pressurization requirements are:
Include credit requirements in all appropriate specification sections. Include the general requirements in Division 1 and others in specialties or furnishings (for the entryway systems) and HVAC (for filtration and other mechanical requirements).
Projects that use their own maintenance staff for regular cleaning of rollout entryway systems must provide a cleaning schedule and narrative along with their documentation.
Develop documentation customized for LEED submission—complete with LEED-related notes, callouts, and details—concurrently with the finalized construction documents.
The contractor is the signatory for IEQc5, even though it's a design credit. Have the contractor review 100% of the construction documents to confirm compliance before completing the design submittal. Otherwise, the credit may have to be deferred until the construction submittal.
Use temporary ventilation systems instead of the permanent HVAC units during construction. This prevents contamination of new ductwork during the construction process.
Use MERV 8 filtration on any permanent mechanical system equipment used during construction. This adds to construction management tasks and could easily be overlooked and lead to loss of the credit. (This requirement appears in the LEED Online credit form as of 10/09, even though it does not appear in the credit language or LEED Reference Guide.)
Make sure that compliance and coordination with this credit is called out in the IAQ management plan if your project is pursuing IEQc3.1: Construction Indoor Air Quality Management Plan—During Construction.
Ventilation and exhaust systems and proper filtration should be included in the commissioning scope for the commissioning credits EAp1 and EAc3.
Provide appropriate training for maintaining entryway systems. If roll-out mats are used, maintain a weekly schedule for cleaning.
Provide adequate training and education for all O&M and cleaning staff in appropriate handling, use, storage, and disposal of hazardous liquids.
Provide appropriate resources and training for O&M personnel to maintain mechanical equipment with MERV 13 filters.
Mechanical systems have to be commissioned to meet the commissioning prerequisite EAp1. The commissioning agent's scope should include confirming appropriate MERV ratings on filtration media and proper operation of designated exhaust systems.
Excerpted from LEED 2009 for New Construction and Major Renovations
To minimize building occupant exposure to potentially hazardous particulates and chemical pollutants.
Design to minimize and control the entry of pollutants into buildings and later cross-contamination of regularly occupied areas through the following strategies:
Projects in East Asia may use filtration media classified as high efficiency (高中效过滤器) or higher as defined by Chinese standard GB/T 14295-2008 (空气过滤器).
Design facility cleaning and maintenance areas with isolated exhaust systems for contaminants. Maintain physical isolation from the rest of the regularly occupied areas of the building. Install permanent architectural entryway systems such as grills or grates to prevent occupant-borne contaminants from entering the building. Install high-level filtration systems in air handling units processing both return air and outside supply air. Ensure that air handling units can accommodate required filter sizes and pressure drops.
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.
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.
The Janitorial Products Pollution Prevention Project is a governmental and nonprofit project that provides fact sheets, tools, and links.
According to the website, 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. Design Tools for Schools “provides both detailed guidance as well as links to other information resources to help design new schools as well as repair, renovate, and maintain existing facilities. Though its primary focus is on indoor air quality, it is also intended to encourage school districts to embrace the concept of designing High Performance Schools, an integrated, whole building approach to addressing a myriad of important—and sometimes competing—priorities, such as energy efficiency, indoor air quality, daylighting, materials efficiency, and safety, and doing so in the context of tight budgets and limited staff."
Environmental Building News feature article describing the benefits and design choices for entryway walk-off systems.
Environmental Building News feature article explaining the various types of air filters, how their performance is measured, and ways to optimize their effectiveness.
Facilitiesnet article covering the basics of air filtration, drawbacks and benefits, standard practices and basic concepts.
Table of filtration efficiencies and their subsequent filtration properties and common applications. Good background on MERVMinimum efficiency reporting value. 13 filtration.
A floor plan like this project example is required to document the presence of entryway track-off systems, length and location. Note that this sample shows six-foot entryway systems because the project predated LEED 2009. For LEED 2009, the systems need to be ten feet in length.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each NC-2009 IEQ credit. You'll need to fill out the live versions of these forms on LEED Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Documentation for this credit can be part of a Design Phase submittal.
Are linen closets and dirty utility rooms required to have exhaust to meet this credit? I know laundry rooms are
I assume that you're asking this question relative to IEQc5? It depends on what's happening in those closets/rooms. If there's chemical mixing, they need exhaust; otherwise, they don't. My guess is that the linen closet doesn't need exhaust, but without knowing what the utility room is being used for, it's hard to say.
Catalina—Health regulations in many US jurisdictions require exhaust to maintain a negative pressure differential in soiled utility rooms in hospitals, surgery centers, nursing homes, and other healthcare occupancies. When this is required, it is usually for odor and infection control. Insofar as odors & germs are undesirable contaminants that negatively affect indoor air quality and occupant health, these rooms might be applicable toward IEQc5 even if chemical mixing does not occur.
Clean linen rooms are typically for clean and sterile goods. The same regulations mentioned above often require positive pressure in clean storerooms, so exhaust fans would be inappropriate.
From a LEED point of view, I agree with Helen as the credit intent is regarding the use of chemicals in those rooms. As for the medical planning, your project team will need to determine which year of the "Guidelines for Design and Construction of Hospitals and Outpatient Facilities" the project falls under, if your project is in the US. There is a subsection devoted to Rehab Hospitals.
I'm now working on a project under LEED certification which aims to pursue this credit.
This project has an external parking area (which is included in the LEED Boundary) above grade and external to the building and a naturally ventilated garage, located exactly below the parking area (same extension, 1 level below grade). The natural ventilation is provided by grids (according to the national fire regulation).
The garage below grade is connected to the building through a corridor.
The corridor is separated from the garage by means a vestibule, with deck-to-deck partition and double self closing doors.
May we assume to comply with the credit by creating an overpressure in the vestibule instead of the suggested negative pressure obtained by a strong exhaust from the garage area?
I would think so as long as the positive pressure is at least as the negative pressure would be if you had done it that way. Let's see what Dylan says.
Heads up for those working on LEED Canada NC 2009 projects, 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 872 ruled 5,000 pages per month as the definition limit for a convenience copier. Ruling provided 2012-06-08.
Hi all,I'm now working on a project under LEED certification that aims to achieve IEQc5.
Hazardous gas and chemical use areas are served by sprinkler system as a fire suppression system. If the the hard lid ceiling is drilled by the sprinkler's heads, can we assume that it is still able to demonstrate compliance with this credit?
I haven't run across this issue as a problem. As long as you can demonstrate, if asked, that the gaps around the sprinklers are sealed, you should be fine.
Thank you so much!
We have a project that includes a workshop/studio space. This space will be used to construct small boats and other projects related to the organization's purpose which is marine environmental studies. The shop opens directly to the outdoors and to the interior (main education spaces) as well. As the shop is a "dirty" environment to begin with, we are not providing a mat from the exterior to the shop but will place a mat at the entrance from the shop to the classroom.
The classroom also opens directly to the exterior as well as having the entrance to the shop. In another LEED comment, a contributor mentions walk-off mat carpet tiles. For our small project, it might make sense to install these "walk-off tiles" throughout the classroom space for aesthetic as well as practical reasons. Will this work and what sort of cleaning protocol would be required?
See 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. #10281 (and #10282) regarding carpet tiles as entry systems
I would consider the shop at "outside" since it is a "dirty" environment. As for cleaning I recommend following the criteria for a roll-out mat, i.e. maintained on a weekly basis by a contracted service organization, at a minimum for the 10' at the entry (outside to classroom; and shop to classroom) that is required for the credit.
We're wrestling with the walkoff mat requirement for a recreation center where there is an indoor/outdoor pool - one end of the pool and the roof retract during clement weather to provide an outdoor pool experience, yet the pool area is fully enclosed during cold weather. there is a concrete floored office and lifeguard lounge accessed only from the pool area, and swimmers all must walk through a locker room and shower before walking onto the pool deck. there is a small exterior zone outside of the pool enclosure surrounded by a fence and accessible only from the pool area. A strict reading of the credit requirements would have us placing walkoff mats everywhere, even in areas that are not accessible to the rest of the building which seems a bit odd. We have walkoff mats located at the two building entrances.
I believe you would be fine by just having the walk off mats at the main entrances. Your scenario would be similar to a building having an outside balcony were the occupants have already entered through the main entrance and some may or may not go out onto the balcony, which is not accessible to public traffic. Now if the occupants were going to a private exterior courtyard or playground, areas with dirt and debris, a walk off mat would be needed.
It is about removing dirt from your shoes and not bringing it into the building. Occupants using the pool are not going to be walking in the dirt or public sidewalks and whatever else.
I concur with Todd.
Can someone please explain what exactly is meant by a dedicated exhaust system?
Also - are the self closing doors a requirement or an option? (The reference guide sais this is optional).
I'll let Dylan confirm, but here is how I have always interpreted these requirements:
1. Dedicated exhaust goes directly outside with no opportunity for recirculation. It's ok to be on same exhaust run as toilets.
2. I've always considered self-closing doors as a requirement. There used to be a checkbox on the form. Since it's not there in the 2009 form, and if the reference guide says it's optional, I would go with that, as long as you can document separation and the pressure differential.
Hello, we are working on a commercial office building project. We are intending to meet the requirements of IEQc5 by providing exhaust to the janitor closets. The exhaust rate will exceed what is required by LEED, and due of cost issues we are intending to tie the janitor exhausts to the restrooms adjacent to them on each floor. There will be enough pressure so there will absolutely be no recirculation within those spaces.
Do you think tying in the janitor closet exhaust to restroom exhaust will satisfy the requirements of IEQc5?
I don't see why that would be a problem. In many buildings these would be designed as part of the same system in the base build. As long as you have sufficient negative pressure to meet the requirement you should be ok.
Yes that is standard.
Can alternative methods for duct sealing be used besides plastic wrap? One of our contractors is proposing using foam to seal the end of the duct openings. From what I can tell the SMACNA guidelines are not clear on the specific duct sealing method. Thanks.
Not sure how you use foam to do it. But if it is a tight seal, that should be fine.
I need to know exactly what fulfills the "Hard-lid" ceiling?. I have a false ceiling with gypsum board partitions all over the floor; I need to know - for example - if I place a steel plate inside the false ceiling that is attached to the partitions from above the ceiling boards, would that be considered as "Hard-lid"?
HI Omar, without knowing the full details of your construction, it's not safe to assume so. The requirement is to prevent fumes or gasses from penetrating an adjacent space. Steel would be fine provided you could show the sealing/gasketing around it, or better yet, welding, was airtight. If you are designing to an accepted construction standard that demonstrates this criteria is being met, then your unique assembly will have a much better chance of being accepted, in my opinion.
Good luck to you! David
Omar – 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. #5677 describes the hard-cap ceiling requirement that “construction method and details demonstrate that the assembly is adequate at containing and isolating pollutants/chemicals”:
This is an old, LEEDv2.1 Interpretation, but it is consistent with language in the LEED-2009-BD+C Reference Guide:
“These rooms must be physically separated from adjacent spaces via installation of deck-to-deck partitions or sealed gypsum board enclosures….Drywall ceilings may be used in place of full-height partitions, but acoustical lay-in ceilings are not adequate."
The current LEEDonline IEQc5 form does not appear to require an upload of enclosure details, but you would be wise to prepare such detail in case of question. Reviewers once asked us for details. We also provided written specifications showing that the ceilings were taped, finished, and sealed, providing separation equal to what the gypsum board partitions provided. The reviewers accepted this.
If standard gypsum ceiling construction meets the Credit requirement, a single gypsum ceiling should suffice. Two ceilings (a steel plate above a suspended ceiling) should be unnecessary.
Thanks for the reply David and Jon, that was very helpful. I also need to know; if I place a fixed glass panel in the upper part of the partition (between the gypsum wall and ceiling), with all the needed sealing, will this be still considered as hard lid or not?
What kind of room are you working so hard to get qualified? What activity is taking place in that room? A drywall ceiling construction, exhaust fan are likely required. Any borrowed light or interior glass window would need to be sealed to prevent air migration between spaces. This is going to depend on your glass mounting details.
Yes, everything depends on your glazing details. USGBC based IEQc5 requirements upon standard construction methods. The use of standard glazing systems, proven to provide an effective seal, should not compromise the enclosure, but special, untested glazing methods could be a problem. The further you stray from standard, the harder it becomes to prove that your approach works.
Remember that you must isolate the pollutant source AND provide the required exhaust to achieve a 7-Pa negative pressure differential. As noted in LI#5677, leaks in the enclosure can undermine the exhaust system.
If your enclosure differs significantly from what IEQc5 prescribes, reviewers might ask for testing and commissioning (similar to IEQp2 smoking rooms) to show whether your alternative construction methods meet credit requirements. See LI#5890 for an example of the kind of testing reviewers might require. (http://www.usgbc.org/leed-interpretations?keys=5890)
If this is too much, your design team might wish to rethink their approach to these enclosures.
Susan, the space is for copying and printing.
Jon, I'am considering 5 pa average pressure diff. and 1 pa when the doors are closed as per LEED BD+C 2009.
Jon, Now I understand from the 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 that maintaining 7 pa under all circumstances is an alternative for deck-to-deck/hard-lid. right?
Omar—I apologize for misleading you. The LEED Interpretations that I posted are very old. They contained outdated information. Under LEEDv2.1, EQc5 required a minimum negative pressure differential of 7-Pa at rooms housing pollutant sources. This requirement no longer applies. Under LEED-2009, the minimum differential is only 5 Pa.
To clarify, for rooms where hazardous gases or chemicals may be present or used, LEED-2009 EQc5 requires the following:
.. 1) Provide continuous mechanical exhaust of at least 2.5 L/s/m2 (0.50 cfm/sf) with no air recirculation.
.. 2) Maintain minimum 5 Pa (0.02 inH2O) average pressure differential with adjacent spaces.
.. 3) Maintain minimum 1 Pa (0.004 inH2O) pressure differential when door to room is closed.
.. 4) Doors to such rooms must be self-closing.
.. 5) The walls around such rooms must extend deck-to-deck or the room must be capped with a sealed gypsum board ceiling.
The point behind both LEED Interpretations is that leaks in the enclosure can undermine the exhaust system’s effectiveness. For example, LI#5677 states that lay-in acoustical ceilings are not acceptable. They do not provide a sufficient seal, making it difficult or impossible to maintain the required pressure differential. Likewise, LI#5890 prescribed a rigorous regimen of tests to justify an enclosure that was not airtight.
You have proposed a room enclosure that differs significantly from that prescribed in Item 5 above. If you pursue this alternative compliance path, the LEED Reviewers may require you to provide commissioning and test reports proving that your enclosure is sufficiently air-tight to maintain the exhaust rates and pressure differentials required in Items 1, 2, & 3 above. To avoid costly tests, it might be wise to alter your design.
? My "mental Arithmetic" is still trying to figure out why the physical build characteristics are important if the pressure differential is held.
How do you document that? 2 options: 1) tests, post build 2) design documentation
Providing design documentation that "proves" that the required pressure differential "will be held" should in my opinion show a crackflow calculation (better yet simulation), which is highly dependant on the build characteristics. But you could achieve the dP with a hole in the wall if you "do it right".
What I'm saying is that the requirement of the build characteristic "hard lid" is superfluous, if the specification is "actually" for a pressure differential.
Jon, Thanks for the clarification. I will refer to point no. 5) and LI#5677. in LI#5677 it is stated that: "The suggestion of incorporating a continuous hard (gypsum board) ceiling to the top of the core walls is an adequate alternative to the deck to deck separation requirement".
And the construction I have is continuous gypsum board (not lay-in tiles) above the all partitions. So I intend to make my submittal with this construction supplying all the necessary document/drawing clarifications.
What I was thinking about (before reading the LI) is to attach a plate to the above of the gypsum ceiling boards, with a fixation penetrating the boards and attached to the gypsum walls cross section. But after reading the LI#5677 I intend to make my submittal directly without this plate. And I will be ready for diff pressure readings since that the design includes diff pressure sensors for these zones. Do you think that this will be sufficient?
Jean, i have the same opinion of yours, but you said " if the specification is "actually" for a pressure differential.".
I think LEED might be having unwritten energy considerations in mind, as the presence of a wall opening will require more suction of conditioned air, which is a running waste.
Aggreed. However, EnergyEfficiency would be traded off in EAp2 where it belongs. That is saying it is still accounted for. Generally LEED is an super system because it does not shrink the abillity for ingenuity in design. You can still have curtain glazing, if you make up for it elsewhere. Plus, we don't need extra complications in this system. I've previously also made the point of how this ties in with ASHRAE 62.1.
Re: testing...this has been accepted on our projects to prove compliance with the credit. IMO this is the best way, because it is real and not based on "theory".
Jean & Omar—I agree that, theoretically, if you “do it right” and size the exhaust system appropriately, you should be able to achieve the required pressure differential, even in a leaky room. However, the LEEDonline template only offers the two prescribed separation options, “deck-to-deck partitions” or “hard-lid ceiling” (both with a self-closing door). If you select “Other,” you must document your “Alternative Compliance Path.” This shifts the burden of proof to your project team, and, possibly, leaves them at the mercy of Reviewers.
I also agree that exhaust systems should be commissioned and tested to show compliance. However, I believe that IEQc5 is still typically a “Design Phase” submittal, made as construction begins, long before it is possible to test as-built conditions to “prove” compliance if required to do so by the Reviewers.
Finally, this whole issue may be immaterial.
Are the copiers and printers in these rooms “high-volume” machines? Remember that small, convenience copiers and printers are exempt from IEQc5 requirements. See LI#1938 and the “Bird’s Eye View” comments at the top of this webpage (LEEDuser members only).
My first question is that which part exactly from the Reference guide states that the entryway system should be placed inside the building?
My second question is that should it be (10 ft long and inside the building?) or (10 feet long or inside the building?) as I may understand from the 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
"An exception to the 10 ft length and/or indoor location is acceptable ..."
Omar – The “inside the building” entryway requirement is in the EQc5 Chapter of the LEED-2009 BD+C Reference Guide. In that chapter, look in Section 4 Implementation (page 513 of the first edition). After the first paragraph is the heading “Entryway Systems.” In the third paragraph below that heading, the second sentence reads, “Entryway systems must extend 10 feet from the building entrance INTO THE BUILDING INTERIOR.”
Therefore, the entryway system must extend at least 10 feet (3 meters) INTO the building.
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. #10098 seems to be saying that, if your entry system is at the exterior &/or less than 10 feet long, you will need to write a darned good justification explaining how your alternative approach is every bit as good as (and better than) the prescribed 10-foot indoor system.
If you choose to pursue an alternative approach, it might be wise to submit a formal inquiry describing your proposal prior to implementation to confirm that it is acceptable.
We have a project that has a garage which has storage, mechanical and other occupied spacesOccupied 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. accessed through doors. The occupied spaces have closures on the doors but the storage and mechanical room do not. Does anyone know if we would be in compliance or should the storage room doors have closures on them?
if it makes a difference one cannot access any other area through the storage and mechanical room.
HI Brian, if there are chemicals (or gases) stored or used in the mechanical or storage rooms then they must be fitted with self-closing doors. And these rooms must also have full-ht. partitions (or gyp. bd. ceilings) and be negatively pressurized, all per credit criteria.
Thanks David. There will be no chemicals or gases stored in the mechanical or storage room but they are adjacent to a garage that will have CO2Carbon dioxide. The doors to other occupied spacesOccupied 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. already have closures but what I don't know is if the doors on the storage and mechanical need closures even though they are not occupied spaces.
Good question. Reading the Ref. Guide fine print it states "where hazardous gases may be present....) If these spaces are next to a garage (a steady source of CO and solvent fumes) then this "presence" condition may exist in these two non-occupied spacesOccupied 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.. I personally would include door closers to be safe. Plus, as you know it's desirable for storage and mechanical rooms to have self-closing doors for security reasons. Now, with that said, if the size of the mechanical room and storage room were proportionately small compared to the garage, and if you can assure that any "present" gases in these two non-occupied rooms are contained within full-ht. partitions or gyp. bd. ceiling, you might be able to make a successful argument that they are incidental to the garage, effectively parts of it. But before you go that route I would first consider submitting a 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, realizing the cost and time delay of the CIR may not make this process worthwhile.
My two bits.... Good luck Brian. David
We have a project that has a garage which needs to have self-closing doors and deck to deck walls or hard lid to other areas. We have the deck to deck walls but we only have door closures on the doors to the other occupied spacesOccupied 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. not on the doors for a storage and a mechanical room. Doe anyone know if they would be required?
We are working on a multifamily residential building where many of the units have private terraces or balconies. In this instance, are walk-off mats required at each of the entrances to the balconies? If so, are they required to be 10 feet long? This would be a significant impact on the living/dining or bedroom design adjacent to the balconies.
The credit doesn't apply to balconies.
It's for regular building entrances from the outside. Presumably you have already walked off the dirt when you entered the building.
Hi Ilana, Michelle is absolutely correct. And, just to be specific, it does pertain to (ground-level) terraces, enclosed or not. We had this confirmed this year.
Does anyone know if dishwashing rooms need to meet the exhaust requirements listed in this credit?
Hi Allyson, just my opinion, but I believe you should assume they do need to comply. Even if the project uses a "green" soap product (or other chemicals), as addressed in the LEEDuser narrative (above, last paragraph) a best intentions policy is a weak approach. With that said, I would think most rooms dedicated to washing dishes (or laundry) would want to exhaust directly outside to rid the air of the humidity, and in some cases, the latent heat. So, this may not be so difficult to achieve from the HVAC design/construction aspect. The required door closers and containment/partitioning are probably tougher conditions to meet, I would imagine.
Good luck to you. David
Good morning all! We are currently working on a dining facility with vestibules at the two main points of entry. However, each vestibule measures just over 5'x5' and contains a recessed entryway system that encompasses the entire vestibule space. Has anyone had any success achieving IEQc5's entryway system requirement with this condition? It seems like I've read that you can achieve that requirement if your system spans from wall to wall in that space but I'm unable to locate it at this time. We are going to include a narrative explaining our position and how we are attempting to comply with this credit. However, I wanted to reach out to my fellow LEED Users for additional advice. Thanks so much!
Hi Amari, it seems your condition as described isn't in compliance. The reference guide states "...at least 10 feet long in the primary direction of travel...". If the design cannot be changed to meet this 10-ft distance in each vestibule, then I would have a carpet service company contracted to place 5-foot long carpets immediately after each vestibule, in the building interior. You could add 5 feet of exterior recessed mat systems, but they would need to be protected from the elements, and this may not be practical for several reasons.
If it makes you feel any better I've faced this situation before. The architect was a LEED AP and knew we were pursuing this credit. So frustrating!
Good luck. David
Thanks so much David, I figured that would be the case but wanted to see if anyone else had experience in this matter. The credit terminology seems misleading. They state that if you can provide information that you meet the credit intent, then your condition will be evaluated on a case by case basis. However, I have been unable to locate a case that didn't require the full 10 feet. Thank you for your response and the advice!
David's answer is your safest bet. Here is an interpretation that addresses splitting up the 10' or rationalizing an exception. However, any time you attempt an exception you are taking a risk.
We are working on a factory project for LEED NC Certification. Our query is specific to IEQ CR 5.0 for grates/grilles in all high traffic exterior entryways. As a factory there will be heavily loaded trucks/vehicles will regularly ploy on site from entry and exist points. Trucks will usually come with raw material and same time they will carry finished products worth tons of weight out of the site. Our concern is installation of entryway grates/grilles may not be feasible considering the amount of load the trucks will carry. There is quite possibility that the grates/grilles may not withstand the load and may lead to break down of grates/grills installed.
Our question is will it be possible that we could get an exemption in implementing grates/grilles in high traffic external entrances.
Apart from grates/grilles, project will provide roll-out mats at all moderate/secondary traffic entry points like reception entrance and workers entrances to building and factory, dedicated rooms for copier/printer/Xerox and chemical handling room with MERVMinimum efficiency reporting value.-13 filtration media in each 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. to cater outdoor as well as return air.
Thanks in advance!
Hi JP, I believe you would not be granted an exemption. Steel grates can be installed that will bear the same weight as a concrete slab. If needed the grate could rest on a slab (in a recessed pocket) if the costs of steel structure/support need to be avoided. I would, however, be concerned about the functionality of the grates when handcarts (with smaller diameter wheels) are used, if that is the case.
One other aspect to confirm is that the ventilation design is fully met (negative pressurization and no air remix, meaning direct exhaust to outside.) Also, don't forget the self-closing doors for these chemical storage/handling spaces. And deck-to-deck partitions or hard lid ceilings. Yikes! I think this is the most onerous of all LEED credits...
Good question. In case of parking garages you do not have to provide the grills and grates for the vehicular areas, just at the entry point of the occupants to the other areas of the building. However, parking areas are not permanent work place.
I would give it a try and submit a 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 for this issue.
I can't find it now, but I seem to remember discussion on this forum about a similar situation where the project successfully installed the walk-off mats in between the warehouse area and the office area, essentially treating the warehouse as "exterior". This approach makes sense to me from a contaminant control perspective, if it is impossible to keep contaminants from vehicle traffic from entering the warehouse/industrial spaces. I am considering this approach on a project that has warehouse and office modules. Can someone please confirm that walk-off mats can be placed to "protect" all entrances into an office module if the warehouse module is impossible to "protect" (forklift traffic tracking in dirt), and the warehouse is occupied on extremely rare occasions? Thank you.
As long as you have walk off mats for entryways for pedestrians, and even as noted, between the factory side and the warehouse side, there should be no issue. You do not have to have grilles for vehicles.
I agree with Todd. The intent is to protect people in the occupied building from contaminants that come in on the feet of other people, not vehicles. Warehouse workers are people too. Protect regular pedestrian entries to occupied spacesOccupied 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..
Michelle, does it make sense to you, to place walk-off mats between an office space module of a building and a "warehouse/storage" module of a building (which is rarely occupied)? Thank you.
If the warehouse is "dirty" and people are walking back and forth from the warehouse to the office, then yes there should be walk off mats. Think about how often a contractor or the cable guy comes to your house. I still want them putting on their booties or taking off their shoes when they come in.
acceptable entryway systems include permanently installed grates, grills, and slotted systems that allow for cleaning underneath. Roll out mats are acceptable only when maintained on a weekly basis by a contracted service organization
What we have on our project are two items for an entryway system at regularly used exterior entrances
1) An underlay
2) And on top of the underlay are carpet piles
Both items do capture dirt and allow for cleaning underneath. Not only that but we can definitely maintain it on a weekly basis by a contracted organization…… Can we qualify?
Again the underlay acts as a roll out mat, and the carpet tiles are the top layer. Underneath the carpet tiles is the underlay.
These 2 items are used mostly in big projects or hotelS…
Can someone please tell me if the above qualifies
Hi Jack, frankly I don't think it would qualify. What you've described on the surface is standard carpet tile. I don't see how the underlay pertains in this condition. The USGBC allows roll out mats with proof of a service contract (if audited). The reason for this, I presume, is that these mats are more likely to be cleaned to a higher standard and when they become worn they will be replaced with new carpets by the service provider.
My opinion... sorry! David
There is carpet tile that has a weave that is considered and accepted as walk off mat. If you were to use that instead of a regular tile, i don;t see a reason for your method not being accepted.
There is an interpretation on this question. Basically if the carpet tile is specifically designed for entryways it can be used. http://www.usgbc.org/node/1732542?view=interpretations.
I am with a sustainable resort project in Thailand. Our project has designed shoe storage space in the front of each guest room instead of having walk off mats. LEED Homes 2008 EQ Credit 8: Contaminant control allows for this as option B in place of walk off mats. Could we use this as the basis of an exception for this credit?
Picture a University bldg. shaped to form a slot canyon to provide shaded access to the outdoors. Within the canyon, which includes doors to exit the courtyard, are a few small classroom pods. Does each classroom pod entrance require walk-off mats from the canyon courtyard?
There is also a pod on the roof, accessed directly from internal stairs. But it has an exit door, that may be used for re-entry. We believe re-entry is not "regularly used."
Hi Joyce, I'm afraid that the classroom pods would require walk-off mats. I'm working on a factory project that has a cafeteria with exit doors out onto a patio. The patio itself is contained (fenced), meaning further egress from it isn't intended. We received Final Design Review comments last week from GBCI and they denied us this credit point. We may add walk off mats inside the cafeteria, TBD. I have read that placing part of the walk-off mat on the exterior of the door is allowed, provided it is protected from the elements and cleaned regularly. You may wish to explore this option if interior space is limited. Good luck. David
The Green Facilitator
Specifying and sizing equipment with MERV 13 filters affects both these credits.
If ventilation systems are to be used for building flush-out, they need to be sized to meet the air volume requirements of IEQc3.2 and must be compatible with MERV 13 filtration.
MERV 13 filters will increase fan energy demand as higher filtration ratings increase resistance to airflow and therefore slightly increase your energy demand.
Mechanical systems components will need to be commissioned to confirm appropriate installation of filtration media.
Additional mechanical system capacity may help meet the requirements of IEQp1. Ventilation systems must have MERV 13 filtration on all supply air.
Do you know which LEED credits have the most LEED Interpretations and addenda, and which have none? The Missing Manual does. Check here first to see where you need to update yourself, and share the link with your team.
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