Introduction

Purpose

This guide describes energy efficiency metrics and benchmarks that can be used to track the performance of and identify potential opportunities to reduce energy use of data center HVAC and electrical systems.

Target Audience

This guide is primarily intended for personnel who have responsibility for managing energy use in existing data centers — including facilities managers, energy managers, and their engineering consultants. Additionally, data center designers may also use the metrics and benchmarks described in this guide for goal-setting in new construction or major renovation.

What This Guide Does

This guide provides the following information:

  • An outline of the benchmarking process.
  • A set of performance metrics for the whole building as well as individual systems. For each metric, the guide provides a definition, performance benchmarks, and potential actions that can be inferred from evaluating this metric.
  • A list and descriptions of the data required for computing the metrics.

This guide is complemented by spreadsheet templates for data collection and for computing the benchmarking metrics. [XLS]

This guide builds on prior data center benchmarking studies supported by the California energy Commission. Much of the benchmarking data are drawn from the LBNL data center benchmarking database that was developed from these studies. Additional benchmark data were obtained from engineering experts including facility designers and energy managers. This guide also builds on recent research supported by the U.S. Department of Energy's Save Energy Now program.

What This Guide Does Not Do

This guide does not address IT efficiency and productivity metrics. While the energy benchmarking approach described in this guide can be used to identify potential efficiency opportunities in HVAC and electrical systems, this guide does not in and of itself constitute an energy audit procedure or checklist. (However, benchmarking may be used as part of an energy audit procedure, or to help prioritize areas for more in-depth audits). This guide does not describe detailed measurement procedures and how to calculate savings from the potential actions identified. The reader is encouraged to use the U.S. Department of Energy's DC Pro tool suite to conduct a more in-depth analysis of data center efficiency.

Definitions

A Performance Metric is a unit of measure used to assess performance; e.g. Cooling System Efficiency (kW/ton).

A Performance Benchmark is a particular value of the metric that is used as a point of comparison; e.g. 0.8 is "good practice" for Cooling System Efficiency.