Auditing your building’s energy usage is the first step to gauging how your facility is performing and creating a solid plan for improving its performance. Continuous improvements guided by a detailed energy assessment can help your team correct lingering control deficiencies while achieving high energy performance, improving indoor environment quality, improving tenant productivity, reducing environmental impact and reducing annual energy costs.
Without an energy audit to prioritize your project list based on measurable financial and environmental performance metrics, you may spend money on ineffective or unnecessary projects.
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) outlines three different levels of energy audits. The audit levels differ based on level of effort/analysis and the level of detail of the results and recommendations.
Walk-Through Survey: ASHRAE Level 1
The walk-thorough analysis is the basic starting point for building energy investigations. This stage begins with conducting an energy use analysis by reviewing past utility bills to determine how much energy the building uses and how it compares to similar buildings in similar climates. Next, a walk-through of the building is conducted, including brief interviews with facility operators. From this we are able to propose low-cost/no-cost energy conservation measures and a list of capital improvements that warrant a further level of analysis.
The Walk-Through Survey is most commonly selected when the goal is to confirm that the potential for savings exists, or to help an owner with multiple buildings prioritize which should be assessed in more detail first.
Detailed Energy Assessment: ASHRAE Level 2
The Detailed Energy Audit includes the completion of all aspects of the Walk-Through Survey, as well as more detailed energy calculations and financial analysis of identified Energy Conservation Measures (ECMs) and Energy Efficiency Measures (EEMs). This process is a thorough evaluation of building envelope, lighting systems and controls, HVAC systems and controls, domestic hot water, plug loads and process energy uses. A list of practical measures is developed and analyzed, including the presentation of operating cost reductions and capital expense requirements for each. A Detailed Energy Assessment usually, but not always, includes the use of energy modeling software to assist in energy performance calculations.
Detailed Analysis of Capital -Intensive Modifications: ASHRAE Level 3
The Level 3 audit builds on the Level 2 audit by doing a more in-depth analysis of energy use in the building. Detailed gathering of energy consumption and building controls data is conducted and analyzed more intensely for areas of improvement and potential costs. This may include the installation of temporary or permanent sub-metering equipment for major energy systems. The added level of detail in the analysis of the existing building and proposed energy measures means that cost and savings have an increased level of accuracy. This level of detail can provide higher quality, more accurate data, which is valuable when considering major energy projects that can be capital-intensive.
