This is a request for amplification and update of LEED Interpretation Inquiry No. 1920, EAp2, from 10/15/2007, which was written for LEED-EB v2.0 but is also shown as applicable to LEED-EB v2009. The original Interpretation dealt with data center submetering within an office building in relation to the building\'s ENERGY STAR score. Since ENERGY STAR requirements related to data center submetering have changed dramatically since this Interpretation was written, much of the content no longer applies. Effective June 2010, ENERGY STAR no longer allows exclusion of submetered data center spaces from larger buildings, even when the data center space is less than 10% of the building floor area.There is a new data center benchmarking model within Portfolio Manager, which is based on the magnitude of IT energy use within the data center. Since isolated IT energy has typically not been submetered in office buildings in the past, there is a transition period established by ENERGY STAR from June 2010 to July 2013, during which the benchmarking tool can apply estimates of IT energy use based on the square footage of the data center space. Beginning in July 2013, submeter data will be required, and the new submeters will need to capture IT energy only, not all of the electricity serving the data center space. Therefore, the decision in Inquiry No. 1920 allowing extrapolation of 3 months of data center submeter usage to 12 months in order to exclude the data center from the ENERGY STAR profile no longer applies. However, there is a new situation where extrapolation of usage data from the new IT energy submeters does come into play. Although IT energy submeters are not required by ENERGY STAR until July 2013, in order to maintain a valid ENERGY STAR score at that point, the meters will need to have been in place 12 months prior. So many buildings are now in the process of installing these new submeters to capture IT energy only, and thereby displace the ENERGY STAR-provided estimated data going forward.Our project building was an early-adopter of the new metering scheme and installed an advanced IT energy submeter in its data center in February 2011. This meter has been capturing and recording IT energy data continuously on a 30-minute interval basis. The usage profile is extremely flat from hour-to-hour, day-to-day, week-to-week and month-to-month. We have graphs that show the 30-minute interval electric demand as a flat line 24/7 for 4 months thus far. IT energy is not affected by seasonal weather changes, so this 4-month period is a very solid basis to project 12 months of IT energy usage. We would like to use this data in Portfolio Manager and project backwards for the full 12-month history in order to calculate the building\'s ENERGY STAR score based on actual IT energy use rather than the ENERGY STAR estimated energy use. The data center in question is very energy-intensive, and the actual submetered IT energy is much higher than the ENERGY STAR estimated data. The impact on the building\'s ENERGY STAR score from the difference between 12 months of submetered actual IT energy data and the estimated data amounts to 9 to 10 ENERGY STAR points.Since the ENERGY STAR score using the actual submetered data provides a more accurate picture of the building\'s energy efficiency performance than applying the ENERGY STAR industry-average estimated data for IT energy, we would like to use the ENERGY STAR score that is based on the actual data. At the time of submittal, we will have 5 to 6 months of the submeter data, which we will extrapolate back another 6 to 7 months to generate a current ENERGY STAR score. We will also provide the tabular and graphical meter output reports to show the consistently flat usage profile throughout the data collection period.Since many buildings will be in a similar situation during the ENERGY STAR transition period through at least July 2013, a LEED Interpretation establishing the minimum acceptable time period for IT energy submeter data to be extrapolated to a full 12-month history in ENERGY STAR for EAp2 and EAc1 would be very useful. The Interpretation could also stipulate a requirement that the consistency of IT energy use be demonstrated during the measurement period to validate the accuracy of extrapolating the data over a longer period.
Project teams that do not have a full 12 months of monitored IT energy data, per the Energy Star requirements issued in June 2010, and effective July 2013, may still be eligible to meet EAp2 and EAc1, though an official Energy Star Rating cannot be earned. The project team is permitted to backwards project up to nine months of IT actual measured data to obtain an Energy Star score in Portfolio Manager, provided that the following conditions are met:
1. A minimum of three months (and including all available data) of metering has been provided that aligns with the minimum length of the permitted performance period AND
2. The monitored consumption is demonstrated to have little variability (with a standard deviation of 2kW or less) over the monitored period, AND
3. Additional documentation is provided to verify that the data center operations have not changed over the course of the year, such as a letter from the data center operator confirming that the quantity and type of servers, server applications, and data processes operating in the data center during the nine months where the IT loads for the data center were not monitored are consistent with those operating in the data center during the period where the IT loads were monitored.
Applicable internationally.