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" "1741" "2007-03-27" "New Construction, Existing Buildings, Commercial Interiors, Core and Shell, Schools - New Construction" "EQc1 - Outdoor air delivery monitoring" "Our facility\'s HVAC system consists of high-efficiency, packaged, direct-fired \'Cambridge\' Unit heaters, passive intake louvers and powered exhaust fans. There is no ducted air distribution system. We propose to install airflow devices at each of the exhaust fans, instead of the intakes. We feel that this makes sense because the exhaust fans will always be \'on\', whereas the \'Cambridge\' Unit heaters will not, when heat is not required. Furthermore, it follows that measuring air being discharged from the building would be equivalent to measuring fresh air being induced into the building, since fresh air will necessarily replace exhaust air in an equal amount. Considering that this building type can be somewhat porous (when the loading dock doors are open) and, per industry norms, always under negative pressurization, it is most logical to measure air where it is being exhausted (since this necessarily will happen in a controlled way at specific locations), rather than where it is being brought in (which would be variable and would happen throughout the building). In accordance with the requirements of this credit, the airflow metering devices will be tied to alarms to alert building occupants if the prescribed airflow pattern ever fails. Finally, the minimum outside air rate (OAR) will be considerably higher than the minimum prescribed by ASHRAE 62.1-2004. The standard prescribes a minimum OAR of 0.06 cfm/sf for this building type. The specified design OAR of 3 complete air changes per 8 hour interval exceeds this minimum by a factor of 3.66. This will also allow us to achieve EQc2 - Increased Ventilation. Is this allowed?" "The applicant is requesting an interpretation of EQc1 and proposing to monitor exhaust air-flow rather than incoming air flow. Based on the project description and conditions, it appears that this credit is not applicable. The credit is specifically intended to address issues with ventilation in environments where a fixed amount of minimum outside air is provided through a specific incoming path. Since the path of incoming air in this project can vary significantly, it would be nearly impossible to trouble-shoot any problems in the ventilation system through the proposed monitoring system. Based on the project narrative, it appears that this project would be best served by a CO2/ CO monitoring system that has alarm triggers." "None" "None" "LEED Interpretation" "1840" "2007-08-13" "New Construction, Existing Buildings, Commercial Interiors, Core and Shell, Schools - New Construction" "EQc1 - Outdoor air delivery monitoring" "To monitor outside air intake we propose to utilize the DDC controls to measure temperatures for the outside air, return air, mixed air, and supply air. The DDC calculations will result in the total CFM of outside air delivered well within the 15% accuracy required. Additionally, the controls configuration will provide alarms whenever the delivered amount of outside air is below the minimum threshold. As a secondary measure, CO2 sensors will be required for ALL building tenants per the LEED CI credit EQ 1. This project exceeds the minimum ventilation requirements of ASHRAE Standard 62.1-2004 by well over 30%. These three parameters will ensure that the minimum outside air will be delivered, monitored, and alarmed per the requirements of LEED CS EQ credit 1. Will our proposal meet the intent of this credit?" "The applicant is proposing an alternative outside air delivering monitoring device which monitors temperatures of outside air. The EQc1 credit requirement states for mechanically ventilated spaces: ""For each mechanical ventilation system, provide a direct outdoor airflow measurement device capable of measuring the minimum outdoor airflow rate with an accuracy of plus or minus 15% of the design minimum outdoor air rate, as defined by ASHRAE 62.1-2004."" The system proposed does not directly measure outdoor airflow rates, as flow rate cannot be measured by temperatures; therefore this strategy would not meet the credit requirements. Applicable Internationally. " "None" "None" "X" "LEED Interpretation" "2099" "2008-04-24" "New Construction, Schools - New Construction, Commercial Interiors, Core and Shell, Existing Buildings" "EQc1 - Outdoor air delivery monitoring" "Our office has two projects that have been struggling with the requirements of EQ Credit 1. Although very different in type, they have taken similar approaches to ensuring outdoor air delivery to occupants. 1) The first project is a historic renovation of a low-rise residential building with seven units. Fresh air is delivered to the building via an Energy Recovery Unit (ERU) that exchanges exhaust air from the kitchens and washrooms of the units for 100% outside air, which is delivered to fan powered boxes in each unit. The ERU does not have an economizer or an air damper. 2) The second is the renovation of an existing doubled loaded corridor school building, which does not have a central air conditioning system, but instead uses perimeter unit ventilators to provide and heat outside air. The dampers on these units are controlled by CO2 sensors located at the thermostat, and will meet the intent of the credit. However, a few non-perimeter classrooms and offices cannot accommodate these perimeter unit ventilators, and thus has a centrally located unit ventilator that provides fresh air to these particular rooms. This ventilator also uses 100% outside air, and also has no dampers. Our suggested approach to both of these projects is to use a current transducer to monitor the performance and status of the ERU and unit ventilators, instead of using an airflow monitor as the credit requirements call for. The current of the fan varies proportionally to the load so that if the unit is malfunctioning (decreased or no airflow) it will be clearly indicated by the power being consumed by the fan. The CT monitor would then report immediately to building management who would field verify the problem and determine if maintenance is needed. We feel this approach complies with the intent of this credit for the following reasons: 1. The units are designed to run at a fixed airflow rate at all times, never to be affected by damper positions, and thus the only instance where air is not being delivered at the appropriate flow is if there is a malfunction with the unit. 2. Monitoring the outdoor airflow of units that are equipped with outdoor air dampers is useful because the dampers can be adjusted based on outdoor airflow readings. Our systems, however, do not have an outdoor air damper because they use only outdoor air. If we directly measure the outdoor airflow, the unit has no way to respond or be recalibrated to address excess CO2 in the space. Outdoor air flow monitoring could be performed, but the results would be of little use. 100% outside air systems are an important tool in providing fresh and healthy interior environments. We believe that the CT monitoring approach is the best method by which 100% outdoor air units can be measured, and also addresses the intent underlying tenets of the credit. It can be argued that outdoor airflow monitors could also provide this level of measurement (on or off), but it provides no more value or functionality than the CT monitor suggested here in the case of 100% outside air units. Please comment on whether this strategy can be used in achieving EQ credit 1." "The CIR is asking if current transducer (CT) monitors are adequate devices to monitor outside air delivery. For a constant volume 100% outside air system similar to the one described by the proponent, the CT approach may satisfy the credit requirement for a direct outdoor airflow measurement device, provided the CT device has been properly calibrated during the installation and commissioning process. Properly calibrated, the CT device would alert the BAS to a change in the fan status, which would indicate a change to the amount of outside air being delivered. In order to satisfy the credit requirements the submittal must show how the CT has been calibrated, and must outline the monitoring sequence. If the system is not 100% outside air, or not constant volume, the CT device would not be adequate. Note that the CT device does not relieve the project of the requirement to monitor room CO2 levels in all densely occupied spaces. -NCv2.2 Requirements state clearly that densely occupied spaces (such as classrooms - mentioned in the CIR) must have CO2 concentrations monitored. Applicable Internationally. " "None" "None" "X"