Final answer:
A Level 4 audit is a comprehensive on-site evaluation performed by an energy advisor to analyze in detail a building's energy consumption and recommend energy savings measures.
Step-by-step explanation:
The Level 4 audit, which is an on-site evaluation with an energy advisor, is a comprehensive on-site evaluation that includes a detailed analysis of a building’s energy use. This type of audit is much more thorough than a basic or visual inspection. It involves the energy auditor visiting the site to collect detailed data on the building's energy consumption, including the use of equipment to measure and record various environmental and systems data. The aim is to gain in-depth understanding of the building's energy performance, identify major areas of energy use, and to provide recommendations for energy savings measures that can lead to significant operational cost reductions.
A typical Level 4 energy audit includes a review of building plans, detailed energy consumption analysis, HVAC, lighting, and other systems performance testing, and the use of advanced diagnostic tools. Unlike options A, C, and D, a Level 4 audit is not optional, remote, or limited to visual inspections; it is a rigorous process that requires the auditor to be physically present at the facility.