What are Energy Audits and the Best Practices for Energy Survey and Analysis

An Electrician Men Checking Air Conditioning Unit

What is an energy audit?

An energy audit is an inspection survey and an analysis of energy flows for energy conservation in a building. It may include a process or system to reduce the amount of energy input into the system without negatively affecting the output. In commercial and industrial real estate, an energy audit is the first step in identifying opportunities to reduce energy expense and carbon footprint.

Energy Audit according to ASHRAE

An ASHRAE energy audit, or American Society of Heating, Refrigerating and Air-conditioning Engineers energy audit, is usually the first step to improve energy efficiency in facilities. ASHRAE energy audits are one of the best practices for energy survey and analysis for the energy service industry. There are 3 levels of an ASHRAE energy audit, and each level has its own standards.

Preliminary Energy Use Analysis

This is the most basic energy audit, involving “an analysis of historic energy use and costs. Energy auditors will use this information to compare to similar facilities to decide whether future engineering study and analysis can help improve energy efficiency and produce significant energy savings.

ASHRAE Level 1: Walk-Through Analysis

  • Goal: identify low-cost or no-cost opportunities for energy savings and areas of energy waste
  • Activities:
    • Interviews with facility managers and staffs
    • Review utility bills
    • Inspect the facility (or facilities)

Some places may combine preliminary energy use analysis with walk-through analysis, but the tasks include in these steps are basically the same across different companies.

ASHRAE Level 2: Energy Survey and Analysis

  • Goal: according to the Association for Energy Affordability, ASHRAE level 2 energy audits provide a more detailed building characteristics survey as well as an energy usage and cost analysis using available information, statistics, and testing  
  • Activities: according to the U.S. Department of Energy and Association for Energy Affordability, within level 2, energy auditors typically conduct:
    • Various diagnostic testing, including lighting level assessment, air flow and temperature measurements, solar shading analysis, electrical testing, duct leakage testing, combustion analysis, steady state efficiency testing etc.
    • An energy model or building simulation and engineering calculations in order to create a detailed and cost-effective scope of work.

At the end of this level, energy engineers will draft out proposed energy saving plans, listing “any potential capital-intensive improvements that require more thorough data collection and engineering analysis,” which will be the main tasks for a level 3 audit. The potential costs and savings will also be provided along with the level 2 audit.

ASHRAE Level 3: Detailed Analysis of Capital-Intensive Modifications

  • Goal: according to Newman Consulting Group, an ASHRAE level 3 energy audit focuses on the capital-intensive improvements identified during the level 2 analysis, and the building owner will receive “comprehensive energy models and a detailed report with project costs, expected savings, and a thorough life cycle cost analysis
  • Activities: according to McNaughton-McKay Electric Company and Association for Energy Affordability, during the level 3 analysis, energy auditors will typically:
    • Collect long-term trend data and information about the building’s energy management.
    • Perform calculations on a computer program with a very accurate model to determine “the way the brick-and-mortar building would respond to changes in the energy systems.
Energy Audit Levels

With these 3 levels, facility managers and building owners are able to make informed investment decisions on the buildings’ energy systems.

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Sources:

ANSI/ASHRAE/ACCA Standard 211-2018

ASHRAE Energy Audit Levels Explained | EnergyLink (goenergylink.com)

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