Ashrae Level 1 – Energy Survey/Walkthrough

A Level 1 analysis is applicable when the desire is to establish the general energy savings potential or which buildings in a portfolio have the greatest potential savings. Level 1 results can be used to develop a priority list for conducting Level 2 and 3 audits.

ASHRAE Level 2 – Energy Survey and Analysis

A Level 2 audit involves a more detailed building survey, including energy consumption and peak demand analysis. A breakdown of energy end uses within the building is developed.

A Level 2 energy analysis will identify and provide the savings and cost analyses of all practical energy efficiency measures (EEMs) that meet the owner’s/operator’s constraints and economic criteria, along with proposed changes to operation and maintenance (O&M) procedures.

It may also provide a listing of potential capital-intensive improvements that require more thorough data collection and engineering analysis as well as an assessment of potential costs and savings. This level of analysis will provide adequate information for the owner/operator to act upon recommendations for most buildings and for most measures.

ASHRAE Level 3 – Detailed Analysis of Capital-Intensive Modifications

The third level of engineering analysis focuses on potential capital-intensive projects identified during a Level 2 analysis. It requires more detailed field data gathering as well as more rigorous engineering and economic analyses, often including modeling (simulation) of the annual energy performance of the building and vendor pricing. It provides detailed project cost and savings calculations with a high level of confidence sufficient for major capital investment decisions. It often goes beyond the economic analysis of a Level 2 audit and uses a comprehensive life-cycle cost analysis (LCCA) as a decision-making tool.

Targeted Audits

A targeted audit is an investigation with a limited scope, typically a single energy-using system, central plant, or area of the building. Some examples include lighting-only audits, cooling tower replacements, boiler control assessments, and tenant improvement projects.

A targeted audit will identify and provide savings and cost analyses for retrofits and control strategy improvements for the systems of interest. The level of effort may be tailored to the needs of the facility. Because the audit is limited to a portion of the building, whole-building approaches such as end-use allocation and comparisons with historical utility bills cannot be used to provide a check on analytical methods. Similarly, whole-building simulation is typically not a cost-effective approach except for large systems. For this reason, targeted audits rely on measurements, data logging, and trend data to provide a check on the energy use estimates in the base case.