Assessing the energy performance of HVAC systems in the tertiary building sector by on - site monitoring

The paper discusses the collection and processing of energy performance data as part of the inspection of HVAC systems, aimed at identifying technically feasible and cost-effective Energy Conservation Opportunities (ECOs), as required by the European Directive on Energy Performance of Buildings (EPBD). Case studies developed by the IEE-funded HARMONAC project have shown that low-cost or no-cost ECOs - mostly related to system operation and management (O&M) - can be identified with an effective system monitoring. Building Management Systems (BMS) may be a powerful tool for this task, provided their HW and SW architecture is designed with adequate attention to energy monitoring. Dedicated instrumentation – such as temperature loggers and electricity meters – may also be employed as an alternative / integration to BMS monitoring. The paper also discusses the application of data analysis tools – such as “carpet plots” and “energy signatures” – to the identification of component malfunctioning, control problems, inadequate maintenance, or system schedule optimization, and to the evaluation of achieved energy savings. The final section of the paper is dedicated to the detailed in situ analysis of refrigeration equipment performance.