The objective of an energy audit is to qualify and quantify how a building’s energy using systems are performing, what is required to improve building efficiency, and what will be the benefits of the improvements.
These audits can vary in scope depending on characteristics of a building. It is not entirely possible to know, where the audit process will lead, or what level of effort will be most cost effective until well into the study.
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has defined three levels, of audits. They are usually performed in sequence and the primary determining factor on what level audits are performed is based on the potential and desire for energy savings, building performance, available funding and the relative return on investment.
Following is a summary of the 3 audit levels:
ASHRAE Level 1
- Assessment summary of annual building energy usage.
- Building energy benchmark comparison.
- Walk through survey of energy consuming systems.
- Identify low cost and no cost measures for quick savings.
- Identify potential energy efficiency opportunities.
- Outline applicable incentive programs available.
ASHRAE Level 2
- Breakdown of energy source and end use.
- Perform a detailed survey or retro-commissioning.
- Identification of Energy Efficiency Measure (EEM).
- Estimate cost and energy savings of EEM’s.
- Prioritize EEM’s for limited resources.
- Identify next steps for EEM’s.
ASHRAE Level 3
- Longer term data collection and analysis.
- Whole-building computer simulation, field data calibrated..
- Accurate modeling of EEMs and power/energy response.
- Detailed design of construction documents for EEM’s.
- Bidding level of construction cost estimating.
- Investment-grade, decision-making support.