An energy audit is a comprehensive study, analysis and evaluation of the energy efficiency of a given facility, such as building or industrial installation. Most often such audit includes evaluation of current energy consumption patterns in the facility under examination, verification of the technical condition of the installation, equipment and energy systems, assessment of the thermal insulation quality in order to identify areas where there are heat losses, assessment of the efficiency of ventilation and air conditioning systems, analysis of lighting efficiency in the context of energy consumption and identification of areas for possible improvements.