A Tool to Assess Laboratory Energy Performance
November 11, 2003
The inherent complexity and variety of laboratory types makes comparative assessments and benchmarking of their energy performance a unique and challenging task, when compared to most other building types. Recognizing this challenge, the Labs21 program initiated the development of a national database of laboratory energy performance. This project has three main components.
Metrics: Labs21 has developed a standard set of energy performance metrics that can be commonly used in the design, commissioning, and operation of laboratories (see Table 1). The metrics include both energy use (e.g., kilowatthours per square foot per year) as well as system efficiency (e.g., watts per cubic feet per minute). This set of metrics is intentionally not comprehensive, since the goal was to develop a limited set of key metrics that allow for effective assessment of energy efficiency, without unduly burdensome data collection requirements.
|Table 1. Standard Set of Laboratory Energy Metrics|
Peak cfm/sf (lab)
Avg cfm/peak cfm
|Total Building||kWh/sf-yr (total elec)|
Database Tool: A web-based database tool has been developed to collect, analyze, and display benchmarking data. The tool allows a user to input laboratory characteristics and energy use data via conventional web forms. Password-protected input ensures that the information remains anonymous to other users of the database. Although measured data are preferred, estimated data may also be provided, and the user can indicate this accordingly. Figure 1a shows a portion of the data input form. (PDF 399 KB; 1 page). Download Acrobat Reader.
Data Collection and Analysis: To perform data analysis using the database tool, the user specifies a metric of interest, and can set criteria to filter the data set by lab-area ratio, occupancy hours, and climate. The tool then presents the data analysis in graphical and tabular format, as shown in Figure 1b (PDF 487 KB; 1 page). The database currently has data from about 35 private and public sector laboratory facilities, including Labs21 Pilot Partners. Some of the key findings from the data analysis are:
- There is a wide variation in total energy use intensity, and a relationship between this intensity and lab-area/gross area ratio, weather, and hours of operation.
- Based on the magnitude of peak electrical loads and their relationship to plug load assumptions, the data suggest that plug loads are often overestimated in design, resulting in oversized HVAC equipment.
- There are numerous efficiency opportunities in the ventilation system, as indicated by metrics such as W/cfm (Watts per cubit feet/minute).
Labs21 encourages laboratory operators to use the database to compare their facilities with other facilities using these metrics. Toward this end, Labs21 works with laboratory operators to input data into the database and benchmark their facilities.
The Labs21 Benchmarking Tool can be accessed on the Web at www.dc.lbl.gov/Labs21/Labs21intro.php. For questions and comments, please contact Paul Mathew of the Lawrence Berkeley National Laboratory at 202 646-7952 or PAMathew@lbl.gov.