Entry Type ID Date Applicable Rating System Primary Credit Inquiry (LIs) Ruling (LIs) Related Addenda/LIs Related Resources Campus Applicable Internationally Applicable Country Applicability Reference Guide (Addenda) Page (Addenda) Location (Addenda) Description of Change (Addenda) "LEED Interpretation" "1640" "2006-12-06" "New Construction" "The ASHRAE 62.1-2004 User\'s Guide includes an Excel calculation tool (ASHRAE Tool) which calculates system ventilation efficiency (Ev) and zone ventilation efficiency (Evz). Please advise whether use of the ASHRAE 62.1 User Manual Calculation Tool can be used to document compliance with this LEED credit. The ASHRAE Tool includes inputs for zone air distribution effectiveness (Ez) which is considered equivalent to air change effectiveness (ACE) as noted in EQc2 CIR ruling dated 07/20/2004. The ASHRAE Tool also includes inputs for Space Type, Floor Area of Zone, Design Population of Zone, and Design Discharge Airflow to Zone. The ASHRAE Tool seems to be an alternative method which can be used to determine compliance with this LEED credit. The ASHRAE Tool calculations also seems to be more current and accurate than the allowed LEED option as described in EQc2 CIR ruling dated 07/19/2004 which determines ADPI using an ASHRAE Handbook, and selects Ez from a table in Standard 62.1-2001, Addendum N. We propose the following calculation alternative which is based on the CIR ruling dated 07/19/2004 but has been adjusted if the ASHRAE Tool is used to document compliance with this LEED credit. LEED-NC v2.2 basis credit compliance on system ventilation efficiency (Ev). This method is similar but it identifies Evz values for each zone in both heating and cooling modes which are both required by the CIR ruling dated 07/19/2004. Zone__ADPI__Ez Heat__Ez Cool__Evz Heat__Evz Cool__Evz Min 1 2 n TABLE NOTES: (a) ADPI: Not required if using the ASHRAE 62.1-2004 User\'s Guide Excel Calculation Tool. (b) Ez Heat / Ez Cool: Based on ASHRAE 62-2004, Table 6.2, Zone Air Distribution Effectiveness. Ez Heat equals Ez in Heating Mode. Ez Cool equals Ez in Cooling Mode. (c) Evz Heat / Evz Cool: Based on results calculated by the ASHRAE 62.1-2004 User\'s Guide Excel Calculation Tool using Ez values. Evz Heat equals Evz in Heating Mode. Evz Cool equals Evz in Cooling Mode. (d) Evz Min: Minimum Evz value for heating and cooling modes. Must be greater than 0.90 to meet the requirements of this credit for each zone. We realize that the LEED-NC v2.2 rules can be used document this credit, but the restrictions imposed by the USGBC in using v2.2 rules to document this credit force it to also comply with v2.2 requirements for EQ Credit 1. The v2.2 rules are also based on increasing the minimum amount of fresh air by 30%, and not on achieving a minimum Evz 0.90." "CIR ruling dated 6/8/05 allows for the use of ASHRAE 62-2004 in lieu of ASHRAE 62-1999. If ASHRAE 62-2004 is applied, it must be applied consistently throughout a project in all associated prerequisites and credits referencing ASHRAE 62. Note that ADPI calculations are still required regardless of which version of ASHRAE Standard 62 is used, so Note (a) in the table above is incorrect. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "1918" "2007-09-18" "New Construction" "Our project, a Central Utility Plant or CUP, is the building and site for a district heating and cooling plant. The building houses chillers, boilers, pumps, compressors, and related equipment. Chilled water, steam, and compressed air (for building controls) will be generated within the building and piped to 23 existing buildings through underground piping. The building which houses the equipment will also have administrative office areas. Therefore, there are 2 distinct areas within the building: One area is industrial in nature, and the other is an office area. The industrial areas which house the equipment will be occupied when necessary for maintenance and operation procedures, while the offices will be occupied as typical office occupancies. We seek approval for treating the industrial portion of the project as a non-occupied area, thereby not applying the requirements of the Indoor Environmental Quality (IEQ) category of points to that portion of the project. With intermittent occupancy and reduced flexibility in the choice of (equipment component) materials, the requirements of the IEQ category appear to be inappropriate for the industrial space. ASHRAE 62.1-2004 lists many occupancies, but none of them similar to the equipment area of the CUP in type." "The CIR is asking whether the requirements of EQ category of LEED applies to areas that are not occupiable (per ASHRAE Standard 62.1 2004 definition) or non-occupied (per LEED v2.2 EQc8 definition). The requirements of EQc1, EQc2, EQc6.1, EQc6.2, EQc7.1, EQc7.2, EQc8.1, and EQc8.2 are only applicable to occupiable or occupied areas; non-occupiable spaces that meet either the ASHRAE Standard 62.1 2004 or LEED v2.2 definition can be excluded from compliance with these credits. The requirements of EQp1, EQp2, EQc3.1, EQc3.2, EQc4.1, EQc4.2, EQc4.3, EQc4.4, and EQc5 do not differentiate between occupied (LEED definition) or occupiable areas (ASHRAE definition) and must be applied to all spaces within the building envelope. These credits and prerequisites affect adjacent spaces that might be occupiable and will also ensure that the construction team is not adversely affected by poor Indoor Environmental Quality. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2414" "2009-01-13" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "Our building is a 114,000 sf mechanically ventilated food processing plant, with office space on one side of the building and process spaces and warehouses on the other. The building is to be built in climate zone 4A. To fulfill the intent of this credit, we will be increasing outdoor air ventilation rates to most of our occupied spaces (offices, process areas, and ambient temperature warehouses) by 30% above the minimum as required by ASHRAE 62.1 2004. Our aim is to provide superior air quality in all of the main working spaces of the building. However, there are five refrigerated spaces in the building each with steady temperatures ranging from 10" "The applicant is requesting exclusion of five refrigerated spaces from the requirements of increased outdoor air ventilation rates. As stated in ASHRAE Standard 62.1-2004, occupiable space is defined 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. If the spaces are occupied more than occasionally then, they must meet the requirements of this credit. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2457" "2009-03-02" "New Construction, Existing Buildings, Commercial Interiors, Core and Shell" "Background: The project is a multi-building complex on a military reservation that includes 256,000 square feet of buildings. Included in this total are two office buildings totaling approximately 160,000 square feet, two vehicle maintenance facilities that total approximately 61,000 square feet and four warehouses that total approximately 36,000 square feet. The protocol used in conjunction with the LEED V2.2 Rating System is the LEED-NC Application Guide for Multiple Buildings and On-Campus Building Projects. Issue: This CIR relates to the vehicle maintenance building. Employing the Ventilation Rate Procedure (as opposed to the Indoor Air Quality Procedure) for a facility classed as a ""repair garage"" in ASHRAE 62.1-2004 appears to result in unnecessarily large ventilation requirements. The energy use for the resulting continuous ventilation is significant, and does not appear to be justified based on the results achieved. Discussion: The ASHRAE 62.1 ventilation rate procedure for a ""repair garage"" requires 1.5 CFM per square foot. To achieve a 30% increase in ventilation, the airflow would be 1.95 CFM per square foot. Based on calculated occupancy, this results in between about 390 to 500 cfm/person. Additionally, each repair bay is equipped with a vehicle exhaust pickup (1,400 CFM each) and its own large individual overhead door. The space is heated to 55 degrees with radiant heaters. Each maintenance area is designed for a single-zone 100% outside air system. Operational data for four similar vehicle maintenance facilities at the same reservation was collected. Four years of operational history are available. The outside air ambient condition at these facilities is the same as the proposed installation. The existing facilities are equipped with a full energy management system that permits monitoring of fan run time and indoor air quality (CO and CO2) data. The area ventilation fans for these facilities activate when high CO or CO2 was measured. The measured conditions for the three facilities with occupancy similar to the proposed facility showed CO and CO2 levels were at or near outside air ambient conditions over 95% of the time. The CO levels never exceeded 5 PPM, the CO2 levels never exceeded 800 PPM. The data from these existing facilities indicates that continuous ventilation of 1.5 CFM per square foot or higher would not provide a significant improvement in indoor air quality over demand-controlled (intermittent) ventilation. LEED requires documentation for the increased ventilation credit to be prepared using the ventilation rate procedure in accordance with ASHRAE 62.1-2004. Because the similar building performance data is available, we propose to provide documentation for this project in accordance with the ""indoor air quality procedure"", also in compliance with ASHRAE 62.1-2004, documented IAW paragraph 6.3.2, ""Documentation"", as follows: "".If the design is based on an approach that has proved successful for similar buildings, the documentation shall include the basis for concluding that the design approach was successful."" . This is addressed in the LEED V2.2 Reference Guide but not used because it is somewhat more problematic to document. Providing control to a reduced level of contaminants would produce exceptional air quality for these maintenance bays and fulfill the intent of increased ventilation, while providing reduced energy use and less embodied energy in construction materials. It is also the standard of practice for maintenance facilities. Request: Document increased ventilation in accordance with ASHRAE 62.1-2004, ""Indoor Air Quality Procedure"". Provide increased ventilation via demand-controlled (intermittent) ventilation systems with DDC controls similar to the existing facilities for control of CO2 to 800 PPM and CO to 12 PPM. Both of these concentrations are at least 30% less than conventional criteria, and far less than regulatory levels defined in ASHRAE 62.1." "There are two questions raised by this CIR: 1. Can ventilation rates be determined using the Indoor Air Quality Procedure instead of the Ventilation Rate Procedure in Standard 62.1? No. As stated in EQ Prerequisite 1, the Ventilation Rate Procedure must be used to size the ventilation system. Hence for ""auto repair rooms,"" the exhaust rate must be 1.5 CFM per square foot per Table 6-4. However, demand controlled ventilation using CO concentration may be used to modulate the exhaust rate down when CO levels are low. (See Appendix B in Standard 62.1 for guidelines of maximum CO concentration.) 2. Does the exhaust rate in the auto repair room have to be increased by 30% to meet EQ Credit 2? No. This credit requires that breathing zone ventilation rates required by Standard 62.1 be increased by at least 30%. Breathing zone rates are listed in Table 6-1, so it is those rates that must be increased by 30%. The exhaust rates in Table 6-4 need not be increased to achieve this credit.\n\nUpdate April 15, 2011: Please note that all 2009 projects in multiple building situations must follow the 2010 Application Guide for Multiple Buildings and On-Campus Building Projects, located here: https://www.usgbc.org/ShowFile.aspx?DocumentID=7987. 2009 project teams should check this document for up to date guidance on all multiple building issues. " "None" "None" "LEED Interpretation" "502" "2003-03-11" "New Construction" "Our project is an Environmental Studies Building on a community college campus in California. The building is two stories and roughly 22,000 square feet. It is divided into two wings - one of which is mechanically ventilated with an underfloor system and one of which is naturally ventilated. The naturally ventilated wing is roughly 9,000 square feet and includes some classroom space, tech support areas for the classrooms, and open study and lounge space. We do not have any questions about how this credit applies to the ""mechanically ventilated"" wing. For the Naturally Ventilated spaces, we would like to know what methods we can use to show compliance with the requirements for this credit. We have heard some reference that a simulation run is not the only acceptable path to validation/documentation, one alternative being a detailed airflow diagram and accompanying narrative and related cutsheets based on established principals of natural ventilation. However all of the official language in LEED Version 2.0 and 2.1 appears to point to a ""simulation"" requirement. We believe that the credit\'\'s intent to ""provide for the effective delivery and mixing of fresh air to support the health, safety, and comfort of building occupants"" can be met without a ""simulation"" run being undertaken but would like confirmation as to whether or not this is the case. If a simulation is required, it will add significant cost to the project. The question is: What of the following (alone or in combination) will the USGBC accept as validation that the project meets the credit intent (the following has been listed in increasing order of effort/cost). 1) Conformance with Title-24 requirements for a naturally ventilated space - Section 121(b)1 The code reads: ""Natural outdoor ventilation may be provided for spaces where all areas of the space are within 20 feet of an operable wall or roof opening through which outdoor air can flow. The sum of the areas of the openings must total at least 5 percent of the floor area of each space that is naturally ventilated. The openings must also be readily accessible to the occupants of the space at all times. Air flow through the openings must come directly from the outdoors; air may not flow through any intermediate spaces such as other occupied spaces, unconditioned spaces, corridors, or atriums. High windows or operable skylights should be accessible from the floor."" 2) Airflow diagram(s) based on established principals of natural ventilation 3) Narrative based on established principals of natural ventilation 4) A single-node based simulation using our own internal software that would then provide air change rates for the space (but not air diffusion effectiveness). 5) A multi-nodal cfd based simulation 6) Some other method not listed above We appreciate your clarification on this topic." "The California Title 24 requirements for naturally ventilated spaces (very similar to ASHRAE 62 requirements for naturally ventilated spaces) are appropriate for documenting compliance of a naturally ventilated building with EQ prerequisite 1, but not for documenting achievement of EQ credit 2. The best way to demonstrate ventilation effectiveness in a naturally ventilated building is to develop a multinodal model of airflow. However, a convincing narrative using demonstrated natural ventilation principles, and including diagrams accurately representing the spaces in question, and supporting calculations based on space characteristics could be used to demonstrate achievement of this credit. Such a narrative would need to be well crafted, clear, and convincing. A single node model could be used to support this evaluation, but by itself would not be adequate to demonstrate achievement. Applicable Internationally." "None" "None" "X" "LEED Interpretation" "5093" "2007-11-28" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "In EQc2 , the ""Naturally Ventilated Spaces"" option references the ""Carbon Trust Good Practice Guide 237"". This guide is now a dated publication and recently withdrawn by Carbon Trust, and therefore no longer a viable option for project teams outside the United Kingdom. What document(s) can be used in place of it?" "As of 10/16/2007, the USGBC allows project teams to use the CIBSE AM 10 (Chartered Instituition of Building Services Engineers, ""Natural Ventilation in Non Domestic Buildings""), the CIBSE AM 13 (""Mixed Mode Ventilation"") or natural ventilation & mixed mode ventilation related sections of the CIBSE Guide B2 (""Ventilation and Air Conditioning"") in place of the GPG 237 as options to achieve the credit. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "5094" "2008-01-18" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "The project team is designing a 480-unit four story apartment project in Pasadena, California. We are investigating the increased ventilation strategy required to comply with LEED EQ Credit 2 (Increased Ventilation) for the living areas within these apartment units. We are proposing the following increased ventilation strategy: We intend to utilize the Broan SmartSense" "The project team is designing a 480-unit four story apartment project in Pasadena, California. The applicant is investigating the increased ventilation strategy required to comply with LEED EQ Credit 2 (Increased Ventilation) for the living areas within these apartment units. The proposed strategy makes sense for a project of this type and size. It is suggested that in order to demonstrate compliance with the credit requirements that the applicant include the following with their LEED submittal: 1. Calculations that demonstrate the achievement of this particular strategy for typical residential unit types 2. Relevant drawings, specifications and sequence of operations that will require the set outside air (OA) rates to be provided, 3. A copy of the relevant sections from the commissioning report that demonstrate that the required ventilation rates have been achieved with the doors and windows shut 4. A copy of this CIR ruling. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "948" "2005-02-07" "New Construction" "The credit intent is to, Provide for the effective delivery and mixing of fresh air to support the safety, comfort and well-being of the occupants. We will demonstrate our compliance through the second compliance by submitting a detailed narrative illustrating the design approaches that were used per the ASHRAE Fundamentals Handbook 2001, Chapter 32: Space Air Diffusion, as described in the edition of the Reference Guide (May 2003 edition). We understand from the Reference Guide that in the case of an audit we must provide scale airflow pattern diagrams, among other data, on all major room types. We would like verification of our interpretation of the major room types of our project and our approach to meeting the credit intent. Our major room types are defined on the basis of room size, shape, extent of mechanical recirculation, the location of heat generating objects, and air motion. We have determined that 5 room types can represent the majority of the regularly occupied rooms at the health center. 1) 100 ft2, 4 ACH 2) 100 ft2, 12 ACH 3) 170 ft2, 4 ACH 4) 170 ft2, 9 ACH 5) 400 ft2, 4 ACH All room types above have 1 diffuser in the center of the room, except for room type 5, which has 2 diffusers Assumptions: - tests will be completed in cooling mode because we do not have air-based in-room heating - radiant panels located at the perimeter walls and will negate exterior wall effects - furnishings are neglected because they are minimal in offices and patient rooms and based on literature, will not contribute significantly to our ADPI calculations Hospital rooms, such as operating rooms, requiring specialized ventilation systems are excluded from our testing. These systems are characterized by high air change rates and laminar flow outlets. We feel that the high air change rate is sufficient to achieve the required ventilation effectiveness. Further, this system type cannot be evaluated using ASHRAE\'s Standard 113. We have also excluded non-regularly-occupied spaces such as corridors, storage rooms etc. as defined in credits EQc8 We have also excluded non-typical rooms from the testing process because they are not major spaces. However, ADPI calculations will still be performed on these rooms as per ASHRAE Fundamentals Handbook 2001, Chapter 32: Space Air Diffusion. For each of the 5 major room types, we will provide the following, as per the May 2003 version of the Reference Guide and the : 1. the predicted ADPI as determined by mock ups in accordance with ASHRAE Standard 113; 2. scale diagrams graphically illustrating the air throw patterns and air directions in the test planes. 3. ACE _cooling calculations per the USGBC ruling dated July 19, 2004 Because of the large variety of rooms we are representing, we cannot provide section and plan drawings showing inlets, outlets, furniture and occupants, as requested. Based on preliminary tests we expect that the test results will support our predicted ADPI. We feel that we will sufficiently demonstrate that the intent of this credit has been met by: 1) following the design recommendations in ASHRAE Fundamentals, Chapter 32; 2) evaluating the ADPI and ACE for all regularly occupied spaces as per the calculation guidelines provided in that document and ASHRAE 62 2001; and, 3) supporting the ADPI calculations with measured ADPI values and scale graphic airflow illustrations at two sections each for the 5 major room types described, We propose to base the design on test results acquired during the design phase. The test results will be submitted, as described above, to demonstrate that the design meets the credit intent to provide for the effective delivery and mixing of fresh air to support the safety, comfort and well-being of building occupants. Please advise us whether this approach is acceptable." "The course of action proposed by the applicant is above and beyond what is required. Per the EQc2 ruling dated 7/19/2004, provided the HVAC design has been developed according to Chapter 32, Table 4, ADPI Selection Guide, for an estimated ADPI of at least 80%, one may use the Zone Air Distribution Effectiveness, Ez, , in ASHRAE Standard 62-2001, Addendum n, Table 6.2, to identify the ACE for each zone."" This does not require testing to establish the estimated ADPI. Measured values and graphic airflow illustrations are not needed. Since the heating is not air-based, the heating mode need not be considered if heating occurs in the zone during occupied hours. The EQc2 ruling dated 7/19/2004 provides guidance and useful examples of how to use the ACE calculation procedure once the minimum ADPI of 80% has been established; it also illustrates how to average the ACE for heating and cooling. The establishment of major room types is a reasonable way to approach the calculations. In addition to the major room types given, other regularly occupied rooms such as waiting rooms and operating rooms should be addressed. Contrary to your statement, ASHRAE Standard 113 may be used to measure ADPI of operating rooms as the scope of this test method says that the method is applicable to all types of supply outlets. Furthermore as stated in the EQc2 ruling dated 7/19/2004, the ADPI need not be measured but may be estimated from Table 4 in Chapter 32 of the ASHRAE Handbook of Fundamentals. Please note that higher ventilation rates do not correlate with better mixing of the ventilation air. Higher ventilation rates (ach) will reduce the air change effectiveness, because at these higher ventilation rates the residence time (age) of the air is lower, so there is less time to mix the air. " "None" "None"