IEQc7.1 requires that HVAC designs meet the requirements of ASHRAE Standard 55-2004, which deals with thermal comfort of building occupants. Specifically, ASHRAE 55 requires project teams to address air temperature, radiant temperature, humidity, and air speed. Earning this credit also sets the stage for you to earn IEQc7.2: Thermal Comfort—Verification.
In most cases, designing a system that complies with ASHRAE-55 is standard practice and documentation is the only LEED-specific requirement for achieving the credit, so it should cost very little to earn.
Meeting this credit in naturally ventilated spaces is tricky, because it’s hard to ensure that thermal conditions remain within the requisite range. It’s really only possible in a few specific climatic regions with especially temperate conditions.
Certain spaces, such as greenhouses, gymnasiums, warehouses or manufacturing facilities often operate outside of the ranges defined by ASHRAE-55, which can put the project in conflict with designing either mechanical and passive systems that meet the credit requirements. If you have these spaces in your project, check with GBCI on whether you can earn the credit through an alternative compliance path.
Regardless of the project type, considering target thermal comfort conditions—and designing to meet those conditions—early in the process is very helpful.
While the credit requirements, and the referenced ASHRAE standard, have not changed from older versions of LEED, the documentation requirements for the credit are now more stringent. Completing the new LEED Online credit form requires greater attention to detail and more supporting calculations, which set a higher bar for coordination among team members.
Supply air volume (CFM) is different from linear air speed measured in feet per minute (FPM). Linear air speed in FPM is relevant to comfort requirements. This information can be derived from the diffuser throw value.
You can establish compliance based on an alternative method to ASHRAE 55.
For spaces with a time-averaged metabolic rate above 2.0 MET, the project must determine acceptable thermal comfort conditions that meet the intent of the credit, and demonstrate that those conditions will be met. 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. #10279 for more details.
For spaces such as warehouses that are not normally conditioned for comfort, the project team may include one or more of the following design alternatives: radiant flooring; circulating fans; passive systems, such as nighttime air, heat venting, or wind flow; localized active cooling (refrigerant or evaporative-based systems) or heating systems; or localized, hard-wired fans that provide air movement for occupants' comfort. Again, see LI #10279 for more details.
The mechanical engineer and architect review ASHRAE-55 along with the credit requirements in the context of the project. ASHRAE-55 requires that you establish a comfort zone based on several variables that affect occupant comfort, and design mechanical systems to create thermal conditions within the comfort zone in each occupied space. Comfort zone calculations are based on the following variables:
Identify any unique programming or climate conditions that might make it tricky to get the credit. Fitness rooms, gyms, natatoriums, or very humid climates often create conditions that require special consideration.
Consider whether mechanical or natural ventilation will be used. When considering natural ventilation systems, review ASHRAE-55 section 5.3 for a description of the relevant requirements.
Include credit requirements in the Owners Project Requirements for the commissioning credits EAp1 and EAc2.
Consider design implications of credit requirements early in program development. For example, if you are in a humid climate you may need additional dehumidification, which will affect your mechanical space requirements.
Consider how credit requirements will affect energy use and occupant experience, and whether programming is consistent with this credit. This credit is particularly worthwhile for any indoor environment in which occupant productivity is of key importance, and where occupants will benefit from optimized indoor thermal conditions.
This credit is generally a low- or no-cost credit. When it does add significant costs, that’s usually because it wasn’t considered early enough, so more equipment has to be added to provide, for example, additional dehumidification. An added cost like that could be prevented by designing the right system early in the schematic design.
In climates where either heating or cooling predominate, or in very humid climates, meeting ASHRAE-55 year-round might require additional system components. For example, spaces that may not otherwise be cooled—like gymnasiums—may need dehumidification or cooling systems to meet the ASHRAE-55 comfort criteria year-round.
It is always important to consider building orientation, the heat-island effect, insulation levels and other design considerations that will have a direct effect on thermal conditions and on the energy consumed to achieve those conditions, but these are not variables that are used as inputs for establishing a thermal comfort zone in ASHRAE-55, so they don’t directly affect whether or not you achieve this credit.
Review how building systems might contribute to or hinder achievement of this credit and review site-specific conditions that will affect building conditioning.
Determine which HVAC system types (mechanical, mixed mode, or natural) and system components can best meet the credit requirements and review any special programming requirements for ventilation, humidity and thermal conditions. For example, consider whether in-floor radiant heating is preferable to forced-air systems and which are best suited to a project’s programming and budget, and confirm that the system will be capable of operating within the established comfort zone.
When beginning to consider thermal conditioning systems, review which system types will not only meet credit requirements, but will balance performance, efficiency and cost while creating an optimal thermal environment in the given climatic region. In some regions, direct evaporative cooling may be an appropriate option, while in others dehumidification may be needed to meet the credit requirements. Review the feasibility of natural ventilation systems versus mechanical systems and consider their effect on energy use, programming, and credit achievement.
Review ASHRAE-55 section 6.1.1 to understand the credit documentation requirements. Assess these inputs:
Review how thermal controls and operable windows affect credit requirements. Projects in very temperate climates may meet the credit requirements through the use of operable windows exclusively, as long as mean monthly outdoor temperatures are between 50°F–92°F. See ASHRAE-55 section 5.3 for details.
Don’t assume that projects in Southwestern or other dry climates will automatically meet the humidity requirements of ASHRAE-55. These climates may have a significant number of days in which operating conditions will exceed the ASHRAE-55 requirements for humidity. Refer to the National Climatic Data Center for regional weather data (see Resources).
Natural ventilation designs are more significantly affected by climate and weather than mechanical systems. Although the methodology and inputs for documenting compliance are the same as for mechanical systems, in certain regions project teams using passive systems may have difficulty meeting ASHRAE-55 due to program constraints or seasonal temperatures that are outside of the prescribed range of 50°F–92°F.
Provide occupant controls for each individual space and avoid trying to normalize conditions in large areas or zones of a building. Separate controls will make it easier to achieve the credit in all spaces and improve occupant comfort while reducing unneeded energy use. For example, if there are ten adjacent offices, provide controls for each office separately. This strategy can also help you earn IEQc6.2: Controllability of Systems—Thermal Comfort. Added controls may increase upfront costs, but reduced energy consumption should help offset those costs.
Examine operating conditions to confirm how likely you are to meet the credit requirements.
Pick the best calculation method for demonstrating credit achievement. Document IEQc7.1 using a Predicted Mean Vote/Predicted Percentage of Dissatisfied (PMV/PPD) calculation, ASHRAE comfort tool, or a psychrometric comfort zone chart from ASHRAE-55. The method you pick will likely be determined by the preference and past experience of the mechanical engineer. (See the Resources tab for software options).
Include the following inputs on the LEED Online credit form:
Make design adjustments to meet credit requirements during design development, keeping in mind the potential impacts on energy use.
Make sure that HVAC engineers track and reconfirm credit-compliant operating ranges through the design development phase.
Make sure that the Basis of Design for commissioning reflects compliance with credit requirements and includes design assumptions and load calculations.
Provide ample thermal controls for building occupants. This will increase comfort and occupant satisfaction and will keep operating conditions within the prescribed ranges of ASHRAE-55.
Occupant access to thermal controls can help to meet the credit requirements on a space-by-space basis while increasing energy efficiency (by preventing conditioning of a whole HVAC zone rather than individual spaces) and increasing occupant satisfaction by giving people greater control over their thermal conditions. Increasing occupant satisfaction will help projects that are attempting IEQc7.2.
Variables like clothing levels and metabolic rates are not compliant or non-compliant, but are used instead to determine what appropriate operating ranges will be for a space. You have to show that your HVAC systems will create conditions within these operating ranges.
Confirm required calculations based on the finalized design by using a PMV/PPD calculation, the ASHRAE comfort tool, or psychrometric zone chart.
Complete all required LEED documentation and upload to LEED Online:
Include ASHRAE-55 related performance requirements in the construction specifications.
Provide LEED documentation requirements in the specifications, including the LEED requirements for information contained in O&M manuals and designating the contractor as the signatory for this credit.
Include LEED references in the drawings and specifications where appropriate.
Make sure that contractor-related LEED documentation requirements and activities are in the specifications so that they are accounted for in estimates and bids.
You might want to defer documenting this credit until the construction submittal to confirm the appropriate system installation and inclusion of the required O&M information.
Develop the Systems Manual, O&M manual, or equivalent. Ensure that the O&M manual includes the following:
The contractor is the signatory for this credit, and has to confirm compliance with the bullets above and sign off on this credit.
Be certain that the commissioning agent reviews the OPR and BOD and confirms that system design and installation will meet the credit requirements for operating ranges.
Set up building operations training to ensure that on-going operation of HVAC systems will meet ASHRAE-55, using the O&M manual for reference.
Encourage general contractors and mechanical contractors, commissioning agents and building operators to review O&M materials and maintenance procedures together to confirm that system performance and maintenance meets the original design intent.
Set up training with O&M staff on proper operating procedures.
Excerpted from LEED 2009 for Commercial Interiors
To provide a comfortable thermal environment that promotes occupant productivity and well-being.
Design heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of one of the options below:
Meet the requirements of ASHRAE Standard 55-2004, Thermal Comfort Conditions for Human Occupancy (with errata but without addenda1). Demonstrate design compliance in accordance with the Section 6.1.1 documentation. Projects outside the U.S. may use a local equivalent to ASHRAE Standard 55-2004 Thermal Comfort Conditions for Human Occupancy Section 6.1.1.
Projects outside the U.S. may earn this credit by designing heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of International Organization for Standardization (ISO) 7730: 2005 Ergonomics of the thermal environment, Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteriaComfort criteria are specific design conditions that take into account temperature, humidity, air speed, outdoor temperature, outdoor humidity, seasonal clothing, and expected activity. (ASHRAE 552004); and 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.
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.
Establish comfort criteriaComfort criteria are specific design conditions that take into account temperature, humidity, air speed, outdoor temperature, outdoor humidity, seasonal clothing, and expected activity. (ASHRAE 552004) according to ASHRAE Standard 55-2004 (with errata but without addenda) that support the desired quality and occupant satisfaction with building performance. Design building envelope (if in project scope) and systems with the capability to meet the comfort criteria under expected environmental and use conditions. Evaluate air temperature, radiant temperature, air speed, and relative humidity in an integrated fashion and coordinate these criteria with IEQ Prerequisite 1: 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, IEQ Credit 1: Outdoor Air Delivery Monitoring, and IEQ Credit 2: Increased Ventilation.
This ASHRAE standard defines the criteria for human comfort that is followed to design mechanical systems.
Information about the ASHRAE Thermal Comfort tool with ordering information.
Information about how to use psychrometric charts.
Download free psychrometric chart software.
Free, easy-to-use program from UCLA that displays climate data in the form of psychrometric charts, among others.
The National Climatic Data Center provides regional weather data that you can use to assess your climate relative to ASHRAE-55 requirements.
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.
These sample documents, from a LEED for Schools 2009 project in Mass., demonstrate how to document that the project meets the thermal comfort design requirements of ASHRAE 55. LEEDuser thanks Christopher Schaffner of The Green Engineer for providing this sample.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each CI-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.
I am using the program above to document IEQc7.1 There is an option for me to calculate the MRT for an individual room. In the project I am working on, I have multiple rooms. Do I have to calculate a MRT for each individual room and document every single one?
Typically we group similar rooms when documenting this credit. LEED is looking for your general design criteria when designing your systems.
Does anyone know of approved methods to prove this credit without completing a full energy model to simulate indoor conditions, in particular radiant heat?
It seems a Psychrometric chart is no longer acceptable.
We have a DC fan coil unit system with VSD control in climate ZoneOne of five climatically distinct areas, defined by long-term weather conditions which affect the heating and cooling loads in buildings. The zones were determined according to the 45-year average (1931-1975) of the annual heating and cooling degree-days (base 65 degrees Fahrenheit). An individual building was assigned to a climate zone according to the 45-year average annual degree-days for its National Oceanic and Atmospheric Administration (NOAA) Division. 2A (Warm/Humid)
Our reviewer is asking for us to provide documentation, such as PMV/PPD calculations or ASHRAE comfort tool results, demonstrating how the thermal comfort conditions have been established for the project and how the design of the conditioning system addresses the thermal comfort design with air speeds greater than 40 feet per minute.
We can do this if we run a full energy model but as it is a small LEED-CI project following prescritpive approach we are not doing modelling.
In the past we have estimated our radiant heat without an issue. We typically submit our psychrometric chart in addition to a PMV/PPD calculation.
If you input over 40 fpm into the PMV calculator often doesn't comply, that is why the LEED reviewer is questioning your design criteria.
Does this credit require 100% comfortable hours (for 90% of the people PMV) or is there some flexibility?
Also - any idea what to do if we can't find an EPW file for Lusaka, Zambia?
There is some flexibility, but you should be close to 100%. The reviewers are looking for you to explain clearly that comfort is being addressed in normal operating circumstances. So for example, failing to provide comfortable hours all summer would not be acceptable, but failing to provide comfort when outdoor conditions exceed design criteria would be.
DOE - Energy Plus site has weather data
If it is not listed, pick something similar and make your case.
Do we need a computer software to calculate the PMV/ for EQ7.1
You can purchase the ASHRAE Thermal Comfort Program to calculate PMV. See the "Documentation toolkit" for samples.
We have a project with office and warehouse. The warehouse is strictly for storage and is occupied only intermittantly for short periods. The warehouse is semi-heated (for freeze protection) and mechanically ventilated. ASHRAE 55 section 2.3 states that the scope of the standard applies to "...spaces designed for human occupancy for periods not less than 15 minutes." Based on this, we do not believe the warehouse should be required to meet the thermal comfort standards of ASHRAE 55.
However, there is conflicting information 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's about this. It is clear that other comfort credits do not apply to non-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. - like daylight and views, thermal comfort and lighting controls - but some of the CIR's insist that all spaces be included in this credit. Can anyone shed light on this? Should'nt we be following the scope of the reference standard?
I am not sure what 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 you are referring to, but spaces that are not regularly occupied like warehouses and storage rooms do not need to meet comply.
On the form simply only enter in information about the spaces that are regularly occupied. I have not had an issue with this on any project.
Anybody else having a problem with elevated air speed (over 40 fpm)? I have a commerical office building with ceiling diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light. with 60 fpm and the credit has been audited for elevated air speed. In this case occupants cannot adjust the diffusers. Seems like this has been cleared up in the ASHRAE 55-2004 addenda such that the graphical method can still be used to demonstrate compliance, but was wondering if anybody else has encountered this, and if so, how did you document the credit?
Has anyone else figured this out?
We have the same review comments and want to know what is acceptible method to prove this using the graphical method.
The credit language says you need to comply with ASHRAE 55-2004 without addenda.
The easiest way to comply is to demonstrate your design criteria is within the ASHRAE perimeters by using the ASHRAE Thermal Comfort Program. See the "Documentation toolkit" for samples.
You can program it as well, using Scilab, Matlab, or any other.
Hi, I am new at documenting LEED credits, and I am stuck in a question. On the particular credit above, at the very end of the form it indicates "Design credit documented". the box next to it has a "0" but I now I have it all documented. Is there a ste that I am missing or does it need to be "comleted" before it can show a "1". Also, if I press complete, will I be able to modify it later down the road? I would appreciate your support.
Augusto, for completing a Compliance Form you cannot leave any field blank. If you have nothing to enter, just input a zero "0" that should do the trick. If you click on Save in the form, you can modify it later.
You can continually updating your form so long as the credit is marked as "In Progress," as can be seen in the Credit Information view within the Credit Details pane.
I am having a tough time seeing how to get this question completed. The 7.1 form, is asking for:
"Hours per typical year that outdoor temperature exceeds design conditions".
Exterior Peak load design conditions?
Interior Design conditions for natural ventilation?
I have looked though the ASHRAE Fundamentals for weather data and do not get how I indicate this. What am I missing? Any insight would be appreciated.
ASHRAE lists cooling design temperatures at 0.4%, 1%, and 2% design conditions. That percentage refers to the percent of hours per year when that temperature would be exceeded. So, if your design conditions are the 1% number, the "hours per typical year that outdoor temperature exceeds design conditions" would be 8760 x 1%, or 88 hours (rounding to the nearest hour).
A LEED-CI project in China, with much challenges indeed. The Chinese MEP when tested general knowledge on thermal comfort design, appears to know how to navigate around the psychrometric chart but sounds unsure how to pen a narrative for submittal and compliance here...maybe a language issue. Does anybody has a simple sample narrative from a previous project, just to get the hang of it?
I'm not seeing that a narrative is required as part of the submittal requirements. Have I missed something? Typically, we just fill out the tables in the credit form, and upload Psych charts showing full and part load conditions.
A narrative was required in the previous (2.2) version of LEED, but it is no longer requried for the 2009 (V3) version. Steve - If you need a sample narrative for a 2.2 project, I have done a few. Thanks for your answer to my posting above Christopher.
Walt, sorry this was meant to be a new thread, but somehow I added to yours, not really relevant to your topic. But yes, it is true that previously we usually just composed a one page narrative and am keen to know what others are doing. Would be good to get just a sample off yours or anyone else out there, can you see my email address?
Instead of a narrative, are the MEP just supposed to fill out the credit form plus pychrometric chart relevant for Shanghai climate just as Chris said above? Is that all?
A general rule in LEED Documentation is to only give the information requested. Reviewers have to review every document you post. If you post extra stuff, that means extra review time, so they get surly sometimes.
I'm a little new to LEED CI (got my AP cred. in NC) and have had intermittent confusion on the scope of LEED CI certification. As I understand it, only work performed as part of the tenant fit-out/remodel can earn LEED credits.
Is it possible to earn this credit by retaining original building HVAC equipment that meets ASHRAE 55. Specifically, I'm working on a hotel that is remodeling all units but keeping the original PTAC window units.
Jeremy- it's a little bit of a gray area, but I think that you should be able to earn this credit if the existing equipment meets the requirements. We have been able to claim WE credit 1: Water Use Reduction for using fixtures that were already in place and this seems like a similar application. I have not personally worked on a hotel using CI, and it seems like it would be a difficult task! Good luck!
I appreciate it Allison. As an update, our certifying body got back to me that yes, existing building equipment can earn LEED CI credits as long as it is used consistently throughout other LEED credits.
fundamental question here: are servicing systems without a humidification function able to fulfil these criteria, providing the local weather conditions should in normal cases not lead to a RH above the Upper Recommended Humidity Limit?
Previous versions of ASHRAE 55 required a minimum humidity. The latest version referenced by LEED eliminated this requirement. You may still want to consider humidification in very dry climates, especially if you're dealing with a museum, hospital, or data center.
really sorry, typed my original query too quickly. I wanted to ask about whether controlled DEhumidification is in all cases required or not.
If no dehumidification is foreseen, but it can be shown that in normal local weather conditions the humidity should not lie above the upper recommended limit, can this credit/ASHRAE 55 be fulfilled? I find the wording in the Standard: "Systems designed to control
humidity shall..." rather unclear - at any rate, it does not say that systems which don't control humidity are definitely ruled out.
Thanks in advance for any help!
You can start by looking at hourly weather data / ASHRAE design data for your particular location to see whether the outdoor design dewpoint is above or below your interior target dewpoint. In many climate zones, use of a 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. system addresses dehumidification adequately, since air will be dried out to maintain a 55F supply air temerature.
In ASHRAE climate zones 1A-4A, I recommend that additional psychrometric analysis at design and part-load conditions be used to determine whether active dehumification is needed - it is usually helpful to include control sequences of operation to describe any actual dehumidification mode. I recommend coordinating with ASHRAE 62.1, which has a description of dehumification analysis, as well as 90.1, which has restrictions on simultaneous heating and cooling, which used to be common for dehumidification.
In my project, it is a swimming stadium. I am confused how I divide the space type. How to consider the swimmer and clothes changer?
Something seems to be lost in translation. I assume you mean the changing room, and is there another space you have a question about?
I have a mechanically ventilated office space & I am trying to document this credit. Can anyone explain to me what is required to meet the requirement to "Upload documentation with inputs and results of calculations or simulations. Include worst case design outdoor conditions and worst case predicted indoor conditions for each month. Show predicted worst case indoor conditions for each month on Figure 5.3of ASHRAE 55." Also, what software did you use (if any) to provide the requested documetation. Your comments are much appreciated.
Craig, can you be more specific about your documentation question? I guess the requirement seems pretty straightforward to me—it would be helpful to have your confusion or question clarified.
Tristan, thank you for your reply & comments.
To clarify my question, it appears to me that the required documentation for this credit is to include the predicted worst case indoor conditions for each month shown on Fig. 5.3 of ASHRAE std 55-2004. However, figure 5.3 of ASHRAE STD 55-2004 is for acceptable operative temperature ranges for NATURALLY conditioned spaces. The space that I am documenting is not a naturally conditioned but a MECHANICALLY conditioned space. ASHRAE STD 55-2004 specifically states this figure is to be used for section 5.3, which is the optional method for determining acceptable thermal conditions in NATURALLY conditioned spaces only. Section 5.3 states “For the purpose of this standard, occupant-controlled naturally conditioned spaces are those spaces where the thermal conditions of the space are regulated primarily by the occupants through opening and closing of windows. This is clearly not the space conditions I have because my space is an office in a high rise building with a built up 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. system and no operable window. I.E. Mechanically conditioned.
So, I would assume that showing the predicted worst case indoor conditions for each month on Figure 5.3 of ASHRAE 55 is not required for a MECHANICALLY conditioned space, but the wording of the requested documentation is confusing to me. On the file Uploads page, it states as follows: “Upload documentation with inputs and results of calculations or simulations. Include worst case design outdoor conditions and worst case predicted indoor conditions for each month. Show predicted worst case indoor conditions for each month on Figure 5.3 of ASHRAE 55.”
Therefore, am I required to upload 12 different graphs (one for each month) of ASHRAE STD 55-2004 fig. 5.3 showing the predicted worst case indoor conditions for a MECHANICALLY conditioned space? Or can I simply upload my calculation or simulation results?
Thank you in advance for your comments & have a great 4th of July.
Craig, where are you seeing a requirement to use figure 5.3?
If this is in LEED Online, double-check which option you have selected at the top of the form—natural or mechanical ventilation. The form will show different fields depending on what you have selected here.
Tristan - Go to the credit information page for credit IEQc7.1 and click on the "file uploads" page or tab. Look directly above the first file upload box and you will find the following: "Upload documentation with inputs and results of calculations or simulations. Include worst case design outdoor conditions and worst case predicted indoor conditions for each month. Show predicted worst case indoor conditions for each month on Figure 5.3of ASHRAE 55."
Yes, I am using LEED Online.
Yes, I have the mechanical ventilation option selected.
Ah, I see. The fact that this is on the file uploads tab is important.
I don't recall the specific instance, but I do recall seeing a case where the file uploads tab simply showed all the files that you MIGHT need to upload for this credit. It did not adjust itself based on the options selected on the form tab. I would think that they don't really mean to require this document. If you want to be sure, I would ask your CB or send a note to GBCI. If you get solid answer, please post it back here.
So basically, if I want to be sure of an answer, I should have asked my CB or sent a note to GBCI. Hmmmm, why in the world would anyone ask a question on this forum then??? What a waste of time, money & resources........
Craig, I agree the certification process can be frustrating and made confusing by ambiguous instructions in the credit requirements or LEEDOnline forms. With the explosion of interest in green building and market demand for LEED has come growing pains and missing links.
There's also an inherent dichotomy at work - between the times when you want to say "just tell me what to do" and the times when you want to say "don't tell me what to do." Earlier versions of LEED sometimes provided less specific guidance and relied on the design teams to use their professional judgement to interpret the credit intent and requirements, and then provide the documentation that they believed would be sufficient. The LEED Reviewer Preliminary Comments, similar to plan check comments, then ask for clarifications. To be sure, time, money and resources have been wasted figuring out what was need to document a credit.
So as the system gets more specific, it get more complicated, and imperfect forms and credit language has been rolled out. Hence the value of the quarterly addenda. For people used to codes and standards that have been refined over many versions and decades, this can be frustrating.
This forum has been able to fill a huge gap. With 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 policy changed to not post publicly and the difficulty of getting specific answers from the CBs or GBCI, the user community has rallied here to share their experiences, insight, and feedback. In some cases, we've gotten "official" responses from GBCI, but not as often as we might like.
I think what can be challenging for many of us using LEED is figuring out when to make our best guess, when to ask a colleague or forum for their interpretation, when to ask for an official ruling, or when to assume a LEED form is in error, explain our assumptions and wait for the review comments to come back.
Hope that helps.
I am encountering an issue with this as well. However, my problem is already part of the preliminary comments. I have a mechanically ventilated space and the reviewer posted the following comment:
"...Provide supporting documentation as required, including...worst case design outdoor conditions and worst case predicted indoor conditions for each month..."
The reviewer has taken this directly from the file upload page and I am unsure of how to provide this calculation in a non-naturally conditioned space. I understand I can submit a written response as part of the re-submission but I would rahter not roll the dice and risk going to appeals since we have already been through the prelminiary review.
By my understanding of the credit, and the credit form, the monthly temperatures are only required to be submitted for naturally ventilated spaces.
1) make sure the box marked "The project building is naturally ventilated, in part or in whole." is not checked.
2) Upload a summary memo, explaining your response to the review comments. In this memo clearly state that the project is mechanically ventilated, and that the "worst case design outdoor conditions and worst case predicted indoor conditions for each month" are only required to be submitted for naturally ventilated spaces.
I am new at this site and I am also having problem with this credit. There is also another upload requirement that states "Upload supporting documentation with PMV/PPD calculation; ASHRAE comfort tool results; and/or psychometric comfort zone chart from Standard 55)." Is there specific software that needs to be utilized to calculate PMV/PPD? It would be a huge help if anybody can comment on this.
Depending on what you are trying to do you may not have to upload any of these.
Because I'm in a humid climate, I generally submit psychometric charts, to show how humidity control is being accomplished, especially at part load conditions.
I think, if you can show:
1) what the comfort zone is for your space type and use,
2) the range of thermal and humidity conditions, how they are achieved, and that they match the comfort zone,
and 3) that the air distribution has been designed so that excess air movement is not a factor,
then you should be all set.
There are a few software tools others have discussed here, and on the NC EQc7.1 page. I don't have firsthand experience with any of them, so I can't make a recommendation, except to say I get along fine without them.
This brief guide introduces some of the key variables involved in designing for thermal comfort.
Principal & Founder
The Green Engineer, LLP
Providing thermal comfort controls will help occupants be comfortable on a space-by-space basis.
Commissioning will help confirm that equipment set points and operating ranges will create system performance that is consistent with the design intent.
Ongoing measurement and verification of mechanical systems will confirm that systems are operating as designed and at levels that maximize efficiency and occupant comfort.
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