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" "2414" "2009-01-13" "New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "IEQc2: Increased Ventilation" "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" "IEQc2: Increased Ventilation" "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" "5093" "2007-11-28" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "IEQc2: Increased Ventilation" "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" "IEQc2: Increased Ventilation" "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"