Energy Management Process

The Process
The first step is to determine which audit is appropriate for a facility, given the complexity of its systems and buildings. Then, information may be collected on the structural and mechanical components that affect building energy use and the operational characteristics of the facility. Much of this information can be collected prior to the site visit. Evaluating energy use and systems before going on-site helps identify potential savings and makes best use of time spent on-site.

The audit consists of three distinct steps: preliminary data collection and evaluation, site visit, and analysis and reporting. An estimate of the time for each step can be made. Allocating time for each step leads to a more comprehensive and useful audit report. The following sections describe the tasks associated with each step of the audit process.

A pre-site review of building systems and their operation should generate a list of specific questions and issues to be discussed during the actual visit to the facility. This preparation will help ensure the most effective use of your on-site time and minimize disruptions to building personnel. A thorough pre-site review will also reduce the time required to complete the on-site portion of the audit.

The first task is to collect and review two to five years worth of utility energy data for all fuels, including electricity, natural gas, fuel oil, and any other delivered fuels. This information is used to analyze operational characteristics, calculate energy benchmarks for comparison to industry averages, estimate savings potential, set an energy reduction target, and establish a baseline to monitor the effectiveness of implemented measures. Several steps must be taken to ensure you have all the information required to do a thorough and accurate evaluation of energy consumption data.

  • Make sure you receive copies of all monthly utility bills (for all meters) and delivered fuel invoices.
  • Sort utility bills by building or by meter and organize them into 12- month blocks using the meter-read dates.
  • Locate all meters and sub-meters. If numerous meters are used, label them on a site plan.
  • Determine which building or space is served by which meter.
  • Calculate the conditioned area (in square feet) for each building.
  • Build the audit portfolio.

Use a computer spreadsheet to enter, sum, and calculate benchmarks and to graph utility information. Record energy units (kWh, therms, gallons, etc.), electric demand (kW), and cost for each fuel type. Units of production (number of units, occupied rooms, students, persons served, etc.) should also be included when energy use depends on production. Relationships between energy use and those factors that drive energy use can be determined by analyzing the data. Some of these factors include occupancy, sales volume, floor area, and outdoor temperatures.

If a building automation system is located in the building, trend and record all pertinent information regarding environmental effects to energy usage, such as:

  • Outdoor air temperature
  • Outdoor air humidity
  • Indoor zone temperatures
  • Fan speeds
  • Condenser water temperatures
  • Chilled water temperatures
  • Economizer activity
  • Misc...