LEVELS OF ENERGY AUDIT
Energy audit can be divided in four levels depending on complexity of projects, detailing of necessary information and achievable results:
Level 0 - Benchmarking - this analysis consists of preliminary Whole Building Energy Use analysis based on historic utility, costs and the comparison of the consumptions of the buildings to those of similar buildings. Actually benchmarking gives an answer about necessity of implementing additional analysis.
The aim of benchmarking is to answer the questions about causes creating good, average or bad energy efficiency in different situations. This first step of energy audit mainly consists of comparing implemented measurements with power consumptions of similar buildings. In the same way, in this stage inappropriate or excessive exploitation costs can be identified to simulation models. However, important aim of benchmarking is to use performance indexes to describe buildings precisely. These indexes are used in most cases:
• Comfort indexes, comparing the actual comfort conditions to the comfort requirements;
• Energy indexes, consisting in energy demands divided by heated conditioned area, allowing comparison with reference values of the indexes coming from regulation or similar buildings;
• Energy demands, directly compared to "reference" energy demands generated by means of simulation tools.
1st level - walk-trough or preliminary audit - In initial analysis energy efficiency of building is being evaluated to prescribe simple, low cost improvements and define measures of power economy requiring further consideration when performing audits. This test is based on visual tests by studying installed appliances, their operation basis and by detailed analysis of power consumption registered in the period of research.
This is the simplest type of audits. It does not include delving in producing process or heat isolation of the building. It is a survey of general producing process resulting in finding weak points of energy efficiency by analysing expenses related to power. In this type of audit only main energy efficiency problems can be fixed. Measures and costs for improving energy efficiency can be quickly prescribed. Also, it is possible to give information about extent of reducing costs and paying off time of potential contribution. In addition, insight in additional energy saving measures is being provided by dividing them by importance.
This type of energy audit is appropriate for prescribing energy consumption as well as it is good midway step for measure exploration of improving energy efficiency and primary situation and making decision about implementing more complete energy audit.
2nd level - General audit - Basing on results of previous audits, in this level of energy audit a survey of power consumption is being performed to provide comprehensive analysis about installed appliances, more detailed analysis about mechanisms, division of used energy and primary evaluation to improve disadvantages or improve current appliances. In this process of analysis measurements are being implemented and computerized modelling is being developed to evaluate the chosen energy modernizing plans precisely.
Producing process measurements are being implemented by examining every step of producing in details to provide an addition for energy audits mentioned before and totality of measures for improving energy efficiency. In addition, energy consumptions for lasting time period (12-36 months) are being analysed to prescribe tendencies of energy consumption. If calculation data of energy meters are available, the information about inexpedient energy losses is being summarized. In addition, measurements are being implemented to make sure about correctness of data. Debate with system service operators is organized for more complete comprehension of producing processes and for clarifying energy losses. In this type of energy audits it will be possible to prescribe more precise measures of energy economy by using results of measurements found. Financial analysis about every necessary measure is being done by basing on calculations of realizing costs, benefit from reducing of process energy and criteria of customer's investments.
3rd level - Investment audit - Detailed analysis, which need a detailed engineering research. Analysis of opportunities of effective energy use related to potentially high costs.