If you reside outside the world of energy efficiency, you might not be familiar with an energy audit. Perhaps you just want to reduce operating expenses by lowering your utility bills? Maybe you need to meet corporate sustainability goals? An energy audit can be the first step in reducing energy use, increasing property value and improving occupant comfort in your building or portfolio.
What’s the goal of an energy audit?
The principal purpose of an energy audit is to identify energy saving opportunities, also called energy efficiency measures (EEMs), in your building. Energy-saving projects can also lead to increased asset values, greater building occupant comfort, lower ownership costs, increased building sustainability as well as improved occupant health and safety.
How do you find energy saving opportunities?
Energy auditors are experienced professionals (well, good ones should be) that identify energy saving opportunities by analyzing your building’s energy use data using on-site observations and collecting data about equipment and building condition. Using their findings, auditors identify financially responsible energy efficiency measures that reduce energy usage and carbon emissions.
Energy auditors will typically consider client’s operational and fiscal goals and constraints when targeting EEMs to find the most favorable return on investments. This provides clients with the information they need to take next steps in implementing the energy projects they are most likely to pursue. After all, there’s no use having a bunch of information about an undesirable project.
Energy audit process
Different types of energy audits result in reports which vary by the amount of time spent on-site, amount of detail and rigor. ASHRAE Level 1 audits are a scoping effort, intended to get an idea of potential for savings and identify some likely projects to pursue. ASHRAE Level 2 audits are the first step for gathering the essential data to identify energy projects that meet your financial goals. ASHRAE Level 3 audits serve as the beginning of energy project development and seeks to minimize risks.
ASHRAE Level 2 Energy Audits
The typical steps of a level 2 energy audit which contribute to the final energy audit report are:
Step 1. Assess preliminary needs and gather initial data. Energy auditor:
- discusses process with client and addresses questions or concerns,
- requests building data (utility bills, mechanical plans, etc.), and
- schedules site visit at client’s building.
Step 2. Site visit, up to full day. Energy auditor:
- inspects energy using systems and building envelope,
- takes spot power measurements,
- installs data loggers if necessary,
- interviews site staff discussing concerns, determines building operation hours and equipment schedules, and
- performs diagnostic testing as necessary.
Step 3. Develop Initial Measures List (IML). Energy auditor:
- develops and delivers preliminary list of EEMs to client, called an IML, and
- discusses EEM priority and interest with client to tailor EEM analysis for the audit report.
Step 4, if necessary. Second site visit to collect and remove data loggers.
Step 5. Energy audit report analysis and delivery. Energy auditor:
- performs building energy analysis to develop EEM,
- writes report, and delivers draft to client,
- discusses report with client and revises as necessary,
- delivers final report to client and discusses next steps for implementation.
Energy audit report contents
A typical ASHRAE level 2 energy audit report for a commercial building has numerous components and typically consists of the following:
- Executive Summary. Describes audit specifics, should be concise but meaningful and include:
- date and place audit occurred,
- total amount of potential energy savings identified,
- table of EEMs summarized with:
- measure names,
- cost and any available incentives,
- payback values or other economic evaluation,
- utility rates used for calculations, and
- any assumptions.
- Project Team and Facility Information. Includes:
- stakeholder contact information for team contributing to audit process,
- facility overview such as:
- size of building/site,
- age of building/site,
- number and type of buildings audited,
- number of occupants,
- hours of operation, and
- description of energy using systems (HVAC, lighting, etc.).
- Energy Consumption Graphs and Analysis. Should include:
- historical energy consumption,
- energy use benchmarking, which compares facility energy use to peers of similar use and size to identify higher consumption buildings, and
- energy balance, which breaks down energy use by end-use.
- Energy Efficiency Measures. Includes:
- analysis methodology, which describes the engineering methods used to perform savings calculations,
- no-cost measure (NCM) recommendations, including savings, costs and assumptions. These EEMs:
- have no associated cost (not including internal labor), and
- reduce energy usage and costs with no capital investment, except for the time and effort of the on-site maintenance personnel.
- low-cost measure (LCM) recommendations, including savings, costs and assumptions. These EEMs:
- have a capital cost that will typically fit within the operating budget, and
- significantly reduce energy consumption and costs while requiring relatively little capital investment.
- capital-intensive measure (CIM) recommendations, including savings, costs and assumptions. These EEMs:
- have a capital cost large enough to require capital expenditure planning, but also
- significantly reduce energy consumption and costs.
- additional measures identified and can include renewable energy projects.
- Calculations and Analysis (supporting recommended measures). Detailed calculations including copies of spreadsheets, models or other analysis.
High quality energy audit reports should contain enough information in each measure to make implementation easier with implementation notes or recommendations provided in the measure description. By choosing a qualified energy auditor, you maximize your chances of receiving this information. Read more about how to how to hire an energy auditor in our previous post.
You can use your in-house staff or hire a consulting engineer for help implementing your project. There can be a lot to manage throughout the process such as submitting incentive applications (if applicable), proposal development, contractor selection, project oversight, final commissioning of installed equipment and measurement and verification. If you need assistance identifying or implementing your next energy saving project, contact us anytime.
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