The Energy Audit

The Energy Audit

The UF IAC analyzes the operating characteristics, energy requirements and energy costs of small and medium-sized manufacturing companies, and identifies and recommends specific Assessment Recommendations (AR’s).

To accomplish this, the UF IAC conducts an audit of each selected manufacturing facility, and provides a thorough analysis of all forms of energy consumption, and of all energy costs.

As a result of this audit, the UF IAC recommends a series of technological improvements – known as Assessment Recommendations (AR’s) – to the plant management based on this audit and analysis. Each AR – including possible recommendations for use of alternate energy sources – is explained, and its costs and benefits are determined and shown. Purchase costs, installation costs, and operating costs are stated separately, so that savings can be clearly computed and demonstrated. A series of economic evaluation measures are provided, including simple payback period, return on investment and a benefit-cost ratio.


Prior to that site visit, the IAC staff confirms that the facility is eligible for IAC Services by obtaining and reviewing the plant’s four digit SIC code, the number of employees, and the annual sales. The energy bill requirements are verified during a preliminary analysis of the plant’s energy consumption records for the preceding year. Several other pieces of information are also obtained in advance of the site visit. One is a sketch of the plant layout, or a full blueprint if available. Another is the plant schedule showing operation hours and shift information. If available, a list of the major energy consuming processes and equipment is very helpful in advance of the visit.

The plant is requested to supply a complete set of cost and quantity of consumption records for all of the forms of energy used at that location. In addition, information on utility rate structures is obtained for electric and gas services. Rates for any other energy supplies are also obtained. This data is analyzed in advance of the plant visit. The cost and consumption data is displayed graphically to show trends, and to potentially discover peaks in usage. One purpose of the audit and analysis is to find the reasons for any peaks found. In some cases the plant does not have all of the energy bills and records needed. Sometimes the necessary information can be obtained from the utility or from the energy supplier.

Site Visit

Once a plant has been selected for a visit to conduct an audit and analysis, and the preliminary information has been obtained and analyzed at the IAC, the next action is to conduct the actual site visit.

Introductory Discussion

First, the audit team – headed by either the IAC Director or Assistant Director – meets with the plant managers or their designated representatives, and discusses plant operations and concerns about energy related matters. Sometimes, peripheral matters such as excessive water costs or waste disposal costs are discussed that have significant energy cost or use implications. During this discussion, the preliminary information on the plant (SIC codes, employees, sales, and energy costs) is verified. The graphs of energy cost and consumption are shown and discussed at this time. Also, at this time, the audit team gives several documents to the plant representatives to identify the UF IAC, the audit team members, the name of the principal contact at the IAC, and a brief description of the audit process to be used.

Plant Tour

Following the discussion of plant operation and existing concerns, the audit team and one or more plant representatives tours the plant and conducts a walk-through audit to understand the operations performed at the plant, and to determine the flow of materials from input or receiving, through processing, and finally to shipping. One audit team member is responsible for taking notes on the manufacturing processes and operations, and another compiles an inventory of major energy using equipment. If the equipment inventory is obtained in advance, then the job is to confirm the list of large energy consuming items.

The plant tour or walk-through is the point at which the experience of the professional staff of the IAC – the Director and/or the Assistant Director – makes a major impact on the quality of the results. Knowledge of manufacturing processes, equipment, and operating procedures is necessary to spot the areas where energy conservation and energy efficiency improvements can be made. Inefficient process heating equipment, low-efficiency motors, large quantities of wasted heat, poor match of fuel forms to process needs, poor process or personnel scheduling, and inefficient scheduling of large electrical loads are only some of the areas where highly experienced personnel can make significant differences in getting good AR’s and alternatives identified.

Information/Data Gathering

Following the initial plant tour, the audit team secures their measuring equipment and proceeds to take and record quantitative information about the equipment in the plant. It is usually best if one of the plant maintenance people accompanies the audit team and works with them to get the necessary measurements. If a plant maintenance person is helping, plant management is less concerned that the audit team will cause some problem. In some cases, the plant person may prefer to take the actual measurement while the audit team confirms the correct procedure.

Combustion efficiency is measured for all major fuel-burning equipment. At the minimum, excess oxygen and stack temperature are measured in oil and gas boilers. Carbon monoxide and carbon dioxide levels are measured if equipment is available.

Efficiency and power factors of large motors and motor-driven equipment are measured when there is reasonable and safe access to power conductors. Clip-on torroidal sensors are used to make current measurements without the necessity of opening up an electrical connection to insert a regular ammeter. Single-phase or three-phase measurements are taken as appropriate to obtain the efficiencies and power factors. Similar measurements are taken when safe and practical for all other large electrically powered equipment. Examples of such equipment include arc furnaces, electrolytic cells, and infrared or induction heaters.

Other factors that affect energy consumption are measured including process temperatures, equipment temperatures, and working temperatures in various plant and office areas. Light levels are measured in most areas of the plant and offices. Air flow and ambient temperature are measured to determine efficiencies of HVAC systems and duct losses throughout the plant.

Assessment Review and Recommendation Development

After the measurements have been completed, the members of the IAC audit team meet for a short while to compile their data, perform elementary analyses, and prepare preliminary AR or alternative energy supply recommendations. Using the information collected, and using data from material brought by the audit team, the team identifies a series of AR’s to reduce the energy-related operating costs of the plant. The primary focus of these AR’s is for improvements to the plant’s manufacturing processes or operations. Equipment modifications and replacements are considered, as well as potential changes in the plant operating schedule or operational procedures.

Wrap-up Meeting

Following the assessment review, the team again asks to meet with the plant representatives for an informal discussion of the audit procedure and any audit results obtained so far.

After the Site Visit

After completing the site visit and presenting preliminary recommendations of AR’s and alternative energy supplies, the IAC staff prepares a formal, Final Report to be sent to the manufacturing company. The report contains a description of the plant operation, equipment, energy costs and consumption patterns, and recommendations together with detailed economic evaluations. After the IAC staff has thoroughly analyzed and evaluated the plant operation and process equipment, there are usually suggestions for improvements that were not made initially. The IAC staff also conducts additional research on processes and equipment after the audit visit, to identify technological products or processes that could help make the particular plant’s operation far more energy efficient and cost-effective.

Final Report

The Final Report is sent to the manufacturing company. A copy of the Final Report – without the plant identification information – is also sent to Rutgers University for their review and suggestions, and final approval.