CI 2009 IEQc7.1: Thermal Comfort—Design

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.

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.

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.

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.

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.

Something seems to be lost in translation. I assume you mean the changing room, and is there another space you have a question about?

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.

I would:

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.