A proposal for an energy conservation opportunities (ECO) list in auditing of air conditioning systems

The main purpose of an Energy Audit is to identify a suitable set of actions that should lead to significant energy savings, within the specified operational and financial constraints. In the Preliminary Audit phase, a set of candidate Energy Conservation Opportunities (ECOs) is identified. The ECOs are selected from a list in which they are grouped into the following categories: Envelope and Loads, Plant, Operation and Maintenance (O&M). In the “Envelope and Loads” categories, ECOs aimed at reducing the building cooling load are listed. These ECOs may be either of the operational type, or may involve renovation work on the building envelope. Therefore, the evaluation methods may be similar to those normally applied either to category “O&M” or “Plant”. “Plant” ECOs involve more or less radical intervention on the HVAC system. Their applicability should therefore be carefully assessed both from the technical and economical standpoint; for this purpose, a review of the main cost-benefit evaluation methods is presented in this report. The “O&M” ECOs include all actions that may in general be implemented in a building, HVAC system, or facility management scheme. The costs involved by such ECOs are generally limited if not negligible: application is therefore normally recommended, provided their technical feasibility is assessed. Several of the ECOs of each of the above categories may be effectively implemented with the aid of a Building Energy Management System (BEMS).