There are many different kinds of energy audits and also varying levels of thoroughness. Therefore, it is important for commercial building owners to properly decide on end goals of their project before making a final decision on the kind of audit that is most suitable in a particular instance. According to the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE), there are three levels of energy evaluations. These are: 1) Level I “Walk Through Assessment” 2) Level II “Energy Survey and Analysis” and 3) Level III “Detailed Analysis”.

Level I – Walk-Through Analysis

The ASHRAE’s Level I energy audit provides an assessment of a building’s energy cost as well as its efficiency. This is done through the analysis of a building’s energy bills and performance of a brief on-site survey of the same building.  The analysis identifies and provides a savings and cost analysis of low-cost/no-cost measures. Also included in the level I analysis is a listing of potential capital improvements that deserve consideration. Along with this there will be a preliminary assessment of potential costs and savings.

Level II – Energy Survey and Analysis

The ASHRAE’s Level II energy audit provides a more elaborate building survey and energy analysis. It provides a breakdown of all the energy consumption within the building.  At this level, you will be able to identify and provide the savings and cost analysis of all practical measures which help in meeting the project owner’s economic constraints and criteria. It also involves a discussion of any changes to operation and maintenance procedures. Also included in the ASHRAE level II energy audit is a listing of potential capital-intensive improvements and these involve more thorough data collection and engineering analysis as well as an assessment of potential costs and savings. Given its thoroughness, this level of analysis is often recommended for most buildings.

Level III – Detailed Analysis of Capital-Intensive Modifications

The ASHRAE Level III energy audit focuses on potential capital-intensive projects that were identified during the Level II energy analysis but provides more comprehensive field data gathering and rigorous engineering analysis.  Furthermore it gives a more robust project cost and savings calculations that provide enough confidence for investors looking to initiate major capital investments.

Putting Energy Audit Data to Use

The object of gathering data about commercial buildings will be defeated if there is no plan in place on how to put it into use. This is why there is a need for a proper energy audit. Such efforts will make it easier to identify and outline the energy efficiency measures (EEMs) needed to reach the target energy reduction goals and meet your capital investment return criteria. There will be specific detail on how the recommended EEMs might be applied, including the expected costs and payback:

Typically, EEMs carrying a five year or less simple payback and usually have the following characteristics:

  1. Lighting retrofits, including lamp replacement and delamping
  2. Control changes, enhancements, and repairs
  3. Retrocommissioning
  4. Adding variable speed drives to pumps and fans
  5. Daylighting controls (where applicable)

Typically, EEMs carrying a longer than five year paybacks usually have the following characteristics:

  1. Changing constant air volume systems to variable air volume
  2. Rewiring of lighting systems for better control
  3. Replacement of package HVAC units to higher efficiency models
  4. Replacement of chillers and boilers in a central plant
  5. Updating to ENERGY STAR