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More fresh air means healthier buildings
More fresh air means healthier buildings. Building on IEQp1: Minimum Indoor Air Quality Performance, this credit calls for exceeding by 30% the minimum outside air requirements set by ASHRAE 62.1-2007. This credit applies only 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. of the building unlike...
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36 Comments
Repair Bays
Repair bayA bay is a component of a standard, rectilinear building design. It is the open area defined by a building element such as columns or a window. Typically, there are multiple identical bays in succession. do not have Ventilation requirement but they do have exhaust requirement. Per the increased ventilation credit would we have to exhaust 30% more outside air?
Based on the language of this credit, the emphasis is on supply side breathing-zone ventilation, rather than exhaust. Has anyone else on this forum had to provide 30% more exhaust to meet this credit?
The credit language does not mention exhaust. The increase in ventilation applied to only 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..That being said if the repair bayA bay is a component of a standard, rectilinear building design. It is the open area defined by a building element such as columns or a window. Typically, there are multiple identical bays in succession. is regularly occupied you may consider providing ventilation.
I have achieved this credits many times without providing information about the buildings exhaust systems.
30% for all spaces individually or for the total ?
We have an overall 30% ventilation above ASHRAE, but it is different in each spaces. Some spaces have 10% more and other have over 40% more. For credit compliance do we need 30% on the total ventilation, or do we need to have 30% for each individual zone?
Every space needs 30% over
Alternative Compliance path for international projects
The USGBC has published a draft for additional guidance for international projects. That includes alternative compliance paths and even additional LEED online forms for international projects. This credit is included in the guideline. Find more here: http://www.leeduser.com/topic/international-projects-alternative-complia...
Increase in Ventilation - Precentage
We are using 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. in some zones of the office building project we are building. When calculating the %-increase in ventilation for the IEQ c2, I wonder what VAV airvalue to use?
The VAV air handlers have 3 values of air, Max - Nominal - Basic. 62.1 in 6.2.5.1 gives directions for use of Basic air volume when calculating Primary Outdoor Air Fraction. My guess would be the Nominal air flow value should be used, this due to the increase in the air supply to theoffice when the KNX detector register an entrance.
One of the most confusing part of this credit is Primary Outdoor Air Fraction (Zp). And I believe LEED just updated their forms as well.
Zp refers to the ratio of the OSA requirement for a space divided by the minimum CFM supply setting (e.g. 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. min box cfm) for that space – the understanding being that as supply air becomes more concentrated with OSA, that OSA is less effective and doesn’t get used by the people prior to being returned to the air handler.
The Ev (efficiency) calculation, is related to the Max Zp value of all the rooms served by a common air handler.
Compliance through natural ventilation
We have a canteen area in one of our projects that is to be naturally ventilated through open windows and ceiling fans. How can you calculate and show compliance with recommendations set forth in the CISBE application manual?
Udana, the CIBSE manual has a diagram process that I think should be clear to follow, if you have a copy. There are also some tips on meeting the credit requirements in the Checklists tab above.
ID credit for 100% outside air
I know there is not an exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. for this credit per say, but I am working on a project where we will using 100% outside air...do you think we could attmept an ID point since we are going above and beyond the requirments? Anyone try such a thing before? THANKS!
Nena - it's my understanding that this credit has more to do with volume of delivered air, so 100% outside air still does not guarantee satisfaction of credit requirements. But if you find out otherwise, please let us know!
Erica is right, it is a matter of volume. You may be able to claim an exemplary performanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. by supplying 60% more outside air then ASHRAE minimum. That would be double what the credit asks for.
Outdoor Air through Revolving Doors
We have a single space in our building (entrance lobby) that is being naturally ventilated through the revolving doors at the main building entrance. How can you calculate the room-by-room airflow in this case for compliance with Option 2 of this credit?
Or is there any prescription in CIBSE AM10 for such a case that we may use to show compliance with Option 1 of this credit?
Thanks.
Omer, could you provide more details on the lobby and the location of the project? I haven't seen a project try to comply with ASHRAE 62 using revolving doors in the past.
Increased ventilation and energy modeling
If we incorporate increased ventilation capacity into our hvac system, do we have to assume the increased ventilation rate for our design building in our energy modeling?
Yes, you do. This is the "energy tradeoff" discussed above under the "Bird's Eye View" tab.
Ventilation in a Fire Station Apparatus bay
Can I use the garage doors in a Fire Department Apparatus BayA bay is a component of a standard, rectilinear building design. It is the open area defined by a building element such as columns or a window. Typically, there are multiple identical bays in succession. as a window to calculate my ventilation for ASHRAE 62.1.? We have have exhaust louvers at the rear of the building.
Michael, I don't see an issue with using the garage doors as the operable area. ASHRAE 62.1-2007 (Section 5.1.1) solely refers to operable wall or roof openings, rather than windows only.
IEQc2: Increased Ventilation
We intend to incorporate demand control ventilation in our project. AHSRAE 62.1 limit on CO2Carbon dioxide concentration is 700 ppmParts per million.. If we have to meet the 30% increase in ventilation air for subject credit, what should be the maximum CO2 concentration in the conditioned space? Our outdoor CO2 concentration is 400 ppm.
700 ppmParts per million. is still an appropriate target for demand controlled ventilation, regardless of the design ventilation rate. With a properly functioning system, the amount of ventilation air supplied to spaces with CO2Carbon dioxide sensors will end up matching occupant loading and will be decoupled from the peak design value (e.g. 20 cfm/person). Increased ventilation will have more of an impact on spaces that don’t have CO2 sensors and likely result in CO2 levels less than 700 ppm.
Hi Conrado
This is a question for ASHRAE 62.1 2007, and more specifically, we find the ASHRAE 62.1 2007 User’s Manual to be super helpful in navigating this credit. The credit addresses the system capacity to supply that 30% extra outside air. It doesn't stipulate CO2Carbon dioxide levels that trigger the call for more outdoor air -- that will depend on the ambient conditions and activity levels of your project. Roger is correct that CO2 sensors support demand control ventilation for some spaces while this credit intent is to include all spaces.
Check out the User's Manual (Appendix A) for CO2 set point and see if it's helpful.
Good luck
The Carbon Trust Good Practice Guide 237 — Natural Ventilation
The Carbon Trust Good Practice Guide 237 — Natural Ventilation in Non-Domestic Buildings — a Guide for Designers, Developers and Owners
I can't find it. Not in the links given or using google.
It no longer exists - it was put back into LEED 2009 accidentally. You want to look at the errata, which references CIBSE AM-10 "Natural Ventilation in Non-Domestic Buildings"
http://www.cibse.org/index.cfm?go=publications.view&item=297
Which Spaces Should Be Included?
The LEED Reference Guidelines mentions "all 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." for this credit. Does this mean "regularly occupied" as in other credits like Daylighting? If you look at Standard 62.1, Table 6.1 includes spaces like UPS room or storage room, which would not be occupied (and which usually are not supplied with outdoor air via dedicated system). Does LEED expect us to show calculations for such spaces as well? Or for example we have an atrium in our building which is conditioned but which will only be used by people walking from one area to other. Does LEED expect this area to be included as well?
Thank you.
Omer, I agree that the definitions of occupied space gets confusing between different LEED credits. I would approach this issue by adhering to the definition of "occupied space" as defined by ASHRAE 62.1. In the old days of CIRs, the USGBC gave the same advice around this definition and ventilation rates. ASHRAE defines occupiable space as "an enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only occupied occasionally and for short periods of time". The USP room in the project you described could be exempt if it is only a storage area. If people work in this area or if it is similar to a mail room, you would need to meet the ventilation rates. The atrium you described would also need to meet the ventilation rates prescribed in ASHRAE as the primary purpose is a hallway for human transit.
Omer, Just to add to the previous comment, this credit seems to use language that singles out "occupied" spaces. However, we still need to comply with the prerequisite, IEQp1, which basically says to follow ASHRAE 62.1. The interesting thing to note is that the 6.1 ASHRAE table for Minimum Ventilation Rates includes all spaces, even storage and electrical equipment room. While they acknowledge that the Rp People Outdoor Air Rate is zero, they still have an Area Outdoor Air Rate that is very small. So, you still need to make sure you are supplying outdoor air to these spaces in some form to meet EQp1.
7th ed. Massachusetts Building Code and ASHRAE 62.1-2004
I am working on a building that is actually registered under v2.2 and using ASHRAE 62.1-2004 or local code for this credit which Mass State Building Code 7th ed. According to the engineers, the local code in Massachusetts exceeds 30% increase over ASHRAE 62.1-2004. Has USGBC/GBCI made any exceptions to this credit? It would not be feasible for use to design for 30% above the local code but we would qualify if it were 30% over ASHRAE.
Thanks
Paul, It's a bit buried, but the Reference Guide does call for 30% above ASHRAE or local code, "whichever is more stringent." Since this credit is out of reach for you if you try to go 30% over local code, and since you're meeting the credit's intent as well as the fundamental requirements as stated in the credit language, I'd suggest you simply submit the credit as 30% over ASHRAE and see how it goes. I wouldn't submit 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 unless you have to after the GBCI/ USGBC review your submittal.
Thank you Seema. I think that is the approach that we are going to take at this time.
In reality the Mass code is going to be the threshold here whether it is attainable or not unless you can get access to a public ruling. THe credit is clear as "whiehevre is more stringent" and I would be shocked if this were not strictly applied. Sorry for the bad news.
Can someone tell me where the BD&C Reference Guide says ASHRAE 62 or local code "whichever is more stringent" for IEQc2? I know this is the case for IEQp1, but I just learned from GBCI that the intent with NC v2.2 is to require 30% above ASHRAE for EQc2, not local code. I just reviewed the Reference Guide and did not see the local code reference in IEQc2, leaving me to believe that this is the same for 2009. Which would be good new for Paul.
Thanks. We are actually applying under the v2.2 system but I don't think that this site covered it when I originally posted the question. We're planning to submit this credit under v2.2 with 30% above ASHRAE. I haven't looked close enough at 2009 Reference Guide to see if the language has changed. v2.2 was just misleading enough to throw off the design team on the intent.
I am asking the same question under NC-2009 and ASHRAE 62.1-2007. In NYS the local code (IMC-2006) is more stringent and we meet th local code for IEQp1. The prerequisite DOES have the wording to meet ASHRAE or the local code whichever is more stringent. However, IEQc2 does NOT have the "or the local code whichever is more stringent" wording. So am I right, is it possible to meet the local code for IEQp1 and use the same values for IEQc2 which exceed 30% over ASHRAE?
NYS MC (IMC 2006) also has an exception paragraph to 403.2 indicating "an registered professional demonstrates that an engineered ventilation system design will prevent the maximum concentration of contaminants from exceeding that obtainable by the rate of ventilation required by....."
this paragraph is generally interpreted by the state as allowing the use of ASHRAE 62.1 being equivalent to the state code when applied by a registered design professional. so it almost sounds like double talk - we can use the state code higher ventialtion, but say we are using ashrae for the credits since technically ashrae is allowed by exception for the state code. does this sound feasible?
Paul, regardless of the logic from your post about NYS, I think you understand the credit properly according to your first post, and should be all set.
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