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Baseline for outdoor air ventilation
This prerequisite establishes a baseline for providing a minimum amount of outdoor air to buildings in order to maintain good indoor air quality and keep occupants comfortable and healthy. This prerequisite references ASHRAE 62.1-2004 (with errata but without addenda) and is often more stringent than local building codes, although it is not likely to entail any added costs.
Two cases, both may be needed
The compliance paths for mechanically ventilated and naturally ventilated spaces, are somewhat different and you may need to follow both paths for the same building. Naturally ventilated spaces must follow the distinct methodology for natural ventilation defined by ASHRAE 62.1, paragraph 5.1, even if other spaces in the same building are mechanically ventilated and are...
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32 Comments
Recent multi family residential review
We are working on a residential building with mechanically ventilated corridors and naturally ventilated dwelling units. Our approach for the mechanically ventilated portions was accepted, but we were denied this prerequisite based on our documentation for natural ventilation. We provided window-to-floor area calculations demonstrating compliance and calculations for naturally engineered cfm for the spaces that are not within 25 feet of operable windows. The LEED Reviewer denied us this credit based on the following, "However, no calculations have been provided to document that these spaces comply with the natural ventilation requirements … Please note that one of the two following calculations would be necessary to document compliance with ASHRAE 62.1 for the dwelling units with occupiable space that is more than twenty-five feet from the windows:
1. The project team may apply the VRP procedure only, rather than pursue any portion of the natural ventilation path, and supply ventilation air through the undercut door. The entire unit space and occupancy must be included and it would not matter if spaces were farther than 25 ft. from operable openings.
2. If submitting for engineered natural ventilation, demonstrate means of continuously delivering or inducing ventilation air to spaces outside 25 ft. (for example continuously operating exhaust/transfer fans) during the occupied periods."
This does not seem in line with our previous LEED reviews that have accepted naturally engineered ventilation induced from intermittent kitchen/bathroom exhaust and pressurized corridors. Has anyone else run into this problem or guidance for documentation moving forward?
ASHRAE 62.1 - 2004 Occupant Density
I am filling out a table similar to Table 1 in EQp1 to demonstrate our project's compliance with ASHRAE 62.1 -2004. I am realizing that our actual population numbers are different than what would be generated from the default occupant density. I am understanding from Note 4 in Table 6-1 of ASHRAE 62.1 - 2004 that I am allowed to use the actual population numbers instead of the default occupant density numbers. Is this correct?
Dave, this is correct. It's helpful to provide a narrative of how the actual population numbers are determined. Using seat count based on furniture plans is usually the most common approach.
Peak Occupancy for ASHRAE and FTEs for other LEED Credits
Any advice on how to address a GBCI reviewer comment that the peak occupancy loads utilized in for the ASHRAE 62.1-2004 standard has to be the same occupancy number for FTEs used in other LEED credits such as SS Cr. 4.2?
Shannon, that seems like a fair comment to me. Are you facing any particular challenges in addressing it?
Help with documenation for this prereq.
After our design review I submitted the following per our reviewer's coments: two distinct ventilation rates for each ventilation zone, both the minimum required ventilation rates prescribed by ASHRAE 62.1-2004, and the actual provided ventilation rates to that zone. However, open final design review they still did denied us the prereq. and said the following: Documentation provided during the Design Review does not demonstrate prerequisite compliance, because the calculations do not contain all the required variables to determine the minimum ventilation rates.
If appealing the prerequisite, the calculations for multi-zone recirculating systems should be sufficient to show that the critical zone was correctly determined for each heat pumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source., and that the peak occupancies predicted and occupiable square footage are aligned with those reported in other credits, and should include corrections for zone air distribution effectiveness (Ez) according to ASHRAE 62.1 Section 6.2.2.2, and for ventilation efficiency (Ev) according to Section 6.2.5.
Keep in mind that Ev can be determined according to Table 6-3 using the maximum zone primary outdoor air fraction (Zp) among all the zones served by the system (heat pump), or according to Appendix A. Also note that the calculations must be conducted for the worst case conditions (generally heating mode), and that Ez is most commonly 0.8 during heating mode. If the value for Ez is greater than 0.8 for this project, please include a short description in the narrative supporting the use of the Ez value used.
The ASHRAE 62.1 Optional EQ Prerequisite 1 Calculator (shown as a credit resource for this credit) may be used to document the required outside air for each heat pump air handling unit. A separate multi-zone VRP Calculation is required for each heat pump. The system level outside air flow listed (“Scheduled OA to HP”) in the provided calculations should meet or exceed the required system level minimum outside air flow from the calculations. The ERV total flow should equal or exceed to sum of all the heat pump outside air requirements. Please refer to ASHRAE 62.1-2004 Section 6.2 for more detailed information and guidance on the Ventilation Rate Procedure.
Although not required to be addressed for this project, please note for future projects, that demand controlled ventilation (DCV) systems which allow the critical zones to be under ventilated, do meet the requirements of ASHRAE 62.1-2004.
I am a little confused - is it just that they now want the Ez and Ev rates? Or something else too? Any input would be great! THANK YOU!
Nena, I'm sorry that this question hasn't yet been addressed on the forum here. Is it still an issue for you? Any further developments?
ASHRAE 62MZ Calc
Anyone have a link to or copy of the ASHRAE 62MZ Calc spreadsheet?
Thanks so much, can't seem to find it any where.
Nelina, there is a link to it in the Resources tab above.
Can anyone tell me how to account for toilet room induced ventilation in the 62MZ spreadsheet?
LEED Facilitation for Cold Storage Facility
Hi,
We are going to setup a Cold Chain Facility (A Multipurpose Cold Storage) which is having
1. 5 Nos of cold chambers with total capacity of 2500 MT designed for a temperature range of 0 deg to 4 deg C to suit the requirement of variety of products.
2. 6 Nos. Deep Freeze Chambers each of 250 MT, 1 chambers of 500MT & 5 chambers of 100 MT. each thus totaling capacity of 2500 MT designed for storage of frozen foods at a temperature range of (-18) to (-)22 deg C.
3. 1 No. 1 No. Pre-cooling chamber of 5MT Capacity to Pre-cool the Fruits & Vegetables from 30 to 35 deg C to 2 Deg C in 6 hrs.
4)4 Nos. ripening chambers for uniform ripening of bananas, 10 MT each chamber.
5)It will have mechanized stacking arrangement, Ante Room, Loading / Unloading dock, Process hall, machine room, offices and toilets.
6)Other facilities like DG Sets, Water based fire fighting system, weighing machines and strapping machines are also included.
My question is whether cold storage facility (details mentioned above) has the possibility to get the LEED Certification? If yes which rating system will be applicable and please inform us the cold storage project which has certified earlier.
Your reply at the earliest will be highly appreciable.
Ramesh,
We were able to achieve a LEED rating for two refrigerated warehouses. Each project included freezers and separate refrgierated spaces, similar to what you mention above. One was the Anheuser Busch refrigerated facility, the other, Gourmet Guru, a food distributor. Both achieved a rating using NC version 2.2.
Ventilation in rerigerated warehouse spaces
On a past LEED project, Version 2.2, it was interpreted that the refrigerated warehouse spaces (deemed a process load due to the nature ofthe facility), required ventilation because there were people working there throughout the day. Their main tasks were loading/unloading only, so it's doubtful that any one person spent a significant amount of time in the space itself.
Has anyone challenged the ventialtion requirement or was this original interpretation incorrect? What was the outcome? Given the delicate nature of maintaing low temperatures and a quality product, it seems that this process load should have been exempt from the 62.1 and 90.1 requirements. It should be noted that assocaited spaces within the warehouse such as offices, did meet the requirements of 62.1 and 90.1.
Lorey, I've asked around and was unable to get help on these questions. Have you learned anything more?
Building corridor
Hi,
A project having a corridor 34.4m long has an operable window (operable size 1.5m x 0.55m) at both ends; the project is naturally ventilated and must comply with ASHRAE 62.1 section 5.1. Does the corridor has to meet the 8m from the operable area requirement of the mentioned standard even if the window is from end to end? Thanks
What do you mean by "the window is from end to end"? Trying to understand the question... thanks!
Direct window opening
Can we use the gross area of an operable window (say 5.5' x 2.0') which can only be opened up to 30 degrees in the computation of natural ventilation compliance calculation? Or should we only use the effective opening since the window can't be fully opened?
Katherine, you can still assume the gross open area (in a vertical plane) for the calculation. Separate from ASHRAE 62 compliance, when a designer looks to calculate effective airflow, a correction factor is used based on the window type.
Thanks Roger!
Hi Roger,
Just a follow up question, can an integrated door (say window is 2.835m x 2.25m w/ integrated door 0.90m x 2.25m) be considered as opening to satisfy requirement for naturally ventilated areas?
Thanks,
Katherine
Katherine, if the door is intended to be open as part of the natural ventilation, I don't see why not. I wouldn't count it, though, if it won't actually be open for this purpose.
LEED V 2.2 EQ Prereqisite 1 Min. IAQ Requirements -CO2 Sensors?
I am finishing up the requirements for LEED NC and am inqiring as to whether CO2Carbon dioxide sensors are required to meet this prerequisite? My Commissioning Agent feels it is a requirement and my HVAC contractor who has done several LEED projects said this has never been a requirment for V 2.2. I know it is a requirment for EQ c1, however, we are goig for that credit. Please calrify?
CO2Carbon dioxide sensors are not a requirement to meet IEQp1. I am not sure why your commissioning agent thinks that—do they give a reason?
The only other reason I can think of why the Cx1. Commissioning (Cx) is the process of verifying and documenting that a building and all of its systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the owner's project requirements. 2. The process of checking the performance of a building against the owner's goals during design, construction, and occupancy. At a minimum, mechanical and electrical equipment are tested, although much more extensive testing may also be included. agent is looking for CO2Carbon dioxide sensors is a requirement in Chapter 6 of ASHRAE Standard 90.1-2004/2007 that CO2 sensors be provided for spaces with occupant density greater than 25 sf/person (with some exceptions and other conditions). This goes beyond LEED and pure code compliance, depending on where the project is located.
Humidity from boiler
Will using boiler or plant steam for humidification cause IEQp1 to be denied?
Kath, could you elaborate on your concern? Humidification is used for facilities all over the country. In New York City, major museums actually inject Con Edison steam directly into the airstream for humidification, even though there have been concerns about the impact of some of the water treatment chemical used on artwork. Are you wondering if you need to provide a clean steam-to-steam generator for humidification or about the use of humidification in general?
Thanks, Roger. . We were told (hearsay) that USGBC is following an ASHRAE 62.1 guideline paragraph that states water for humidifiers shall be potable and therefore they rejected a project that used plant steam. See below.
IEQp1 “Minimum Indoor Air Quality Performance” has a primary focus of confirming that minimum outside air flow requirements are met in accordance with ASHRAE 62.1-2007 “Ventilation for Acceptable Indoor Air Quality” In addition IEQp1 requires compliance with this standard, sections 4 through 7. One paragraph within these sections is:
Paragraph 5.13.1 Water Quality for humidifiers “Water shall originate directly from a potable source or from a source with equal or better water quality”.
Kath, thanks for the clarification. I think in this situation, you probably do want to use a clean steam-to-steam generator to avoid issues with ASHRAE 62.1 compliance. Thanks for bringing up this question in the first place!
Natural ventilation for warehouse
Dear all,
I have a factory project, including sewing plant and warehouse for storage.
In sewing plant we use HVAC system and in warehouse we keep natural ventilation.
So, the question here is:
For sewing plant we will apply section 4-7 of ASHRAE 62.1
For warehouse we will apply paragraph 5.1 ASHRAE 62.1.
Is it right?
Since I saw in LEED template online, we just select 1 option either MEchanical or Natural.
Thanks.
Fabio, it sounds like you have the right approach. As we discuss above in the Bird's Eye View, both cases may be needed in the same building. Perhaps there is a way to do an alternative compliance path, and select both options.
Reuse of Existing Ductwork
We have a major renovation project and in a portion of the buidling we will be replacing rooftop units, but would like to re-use the existing ductwork. Is this allowed and how does it affect or not affect the compliance with 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?
I don't see any reason this would not be allowed. Did you have any specific concerns in mind?
Credit compliance is based on ventilation rate calculations, which I don't think would be affected, as long as you know what you're working with in the building.
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