Background: Our project is a 28,000 sf, two-story MBA educational and office building on a college campus. Our goal is to achieve up to 10 points under the EA c1.2 category. To that end, we are committed to reducing process loads, along with the other measures in the integrated building design to reduce overall energy use. This project primarily has office equipment as the majority of its process energy use. In order to reduce process load energy use in the building, a concerted effort has been made by the client to specify low energy use equipment, including EnergyStar rated equipment, in the building. Our strategy had been to collect all of the nameplate energy data available for the equipment, and enter this data into our proposed case model. However, it appears that nameplate data is not the best indicator of actual energy use from equipment. Numerous ASHRAE research projects confirm that nameplate data rarely reflect the actual power consumption of office equipment, and furthermore that the ratio of nameplate to power consumption also varies widely, from 25 to 50% of nameplate for equipment less than 1000W (ASHRAE Research project RP-1005, Hosni et al. 1999). Further plug load reduction strategies being considered include using occupancy sensor controlled power strips, which will allow monitors and other devices to be turned off when the occupants are not present. Proposed Strategy: Actual measured data of power draw from process uses would be the best data to use to model energy use, however this data is not readily available during design. In the rare case where we do have access to the same equipment to that which would be installed in the project, we would propose to measure the power draw from this equipment and use these results for the proposed case model. In most circumstances though, this is not a practical approach. The 2005 ASHRAE Fundamentals Handbook has looked at this issue in regards to how office equipment produces heat, for the purposes of more accurately assessing cooling loads for sizing HVAC systems. In their work, it is assumed that actual power consumption of the equipment is equal to the total radiant plus convective heat gain from the equipment. The Handbook proposes using two different strategies for determining \'actual\' power consumption and heat gain from office equipment (see highlights in attachments). 1. In cases where only nameplate ratings are available, they suggest that "Generally if the nameplate value is the only information known and no actual heat gain data are available for similar equipment, it is conservative to use 50% of nameplate as heat gain and more nearly correct if 25% of nameplate is used." 2. Much better results are gained, per the Handbook, by considering heat gains based on the type of equipment. ASHRAE publishes a series of tables in the 2005 Fundamentals Handbook documenting energy rates for multiple types of equipment (Chapter 30, Tables 5 through 10). Note that these tables provide information limited only to certain types of equipment. In regards to occupancy sensor controlled devices, the 2005 California Title 24 energy code allows for a reduction in task lighting energy use of 20% when controlled by occupancy sensors, which is based on their studies of the impact of this technology on energy use. Similarly, we would expect a 20% reduction in energy use for plug loads controlled by occupancy sensors in an office environment. Request: Please confirm that the use of measured power draw data from equipment is acceptable for modeling their process loads, when access to the same equipment is available during design. In cases where this is not available, please confirm that the use of the data published by ASHRAE in case #2 above shall be acceptable for equipment that is covered by their tables, and a factor of 25% used per case #1 for all other cases. If occupancy sensor controlled power strips are used for plug load devices, please confirm that those devices connected to the power strip can be modeled as having a 20% annual power savings. References: 2005 Building Energy Efficiency Standards SECTION 146 - PRESCRIPTIVE REQUIREMENTS FOR SERVICE WATER HEATING SYSTEMS (a) Calculation of Actual Indoor Lighting Power Density. The actual indoor lighting power of the proposed building area is the total watts of all planned permanent and portable lighting systems (including but not limited to, track and flexible lighting systems, lighting that is integral with modular furniture, workstation task lights, portable freestanding lights, lights attached to workstation panels, movable displays and cabinets, and internally illuminated case work for task or display purposes), subject to the following specific requirements and adjustments under Subsections 1 through 6. 4. Reduction of wattage through controls. The controlled watts of any luminaire may be reduced by the number of controlled watts times the applicable factor from TABLE 146-A if: TABLE 146-A LIGHTING POWER ADJUSTMENT FACTORS TYPE OF CONTROL TYPE OF SPACE FACTOR Occupant sensor with "manual ON" or bi-level automatic ON combined with multi-level circuitry and switching Any space ?? 250 square feet enclosed by floor-to-ceiling partitions; any size classroom, corridor, conference or waiting room 0.20 2005 ASHRAE HANDBOOK- FUNDAMENTALS page 30.8 to 30.10 Office Equipment - Nameplate vs. Energy Use Table 8 - Recommended Heat Gain for Typical Computer Equipment. Table 9 - Recommended Heat Gain for Laser Printers and Copiers