Auditing the European room air-conditioning systems and potential energy savings

Daniela Bory, Jérôme Adnot, Carmelo Greco, and Dominique Marchio, Center for Energy and Processes, France

Keywords

air-conditioning performances, defect, operation, energy savings

Abstract

Nowadays, the European Community promotes the energy improvement of the air-conditioning (AC) systems through the compulsory inspection of these facilities in the frame of the Energy Performance of Buildings Directive [EPBD, 2002]. Inspection itself is just a motivating mean for the AC actors to improve the energy efficiency of the systems and reduce energy. Therefore, the aim of the inspection is to follow periodically the correct management of the facility through a quick visit of the plant and a study of the available documentation while the aim of the audit is the research of best efficiency improvements which requires further investigations to evaluate and quantify the savings. Audit differs from the common maintenance activities of the facilities, the aim of which is limited to guarantee the basic operation of the plant. There is an overall lack of methodologies specific for air-conditioning and the improvements proposed are seldom proven with scientific rigour. For room air conditioning systems, the impacts of defect during operation due to ageing and neglected maintenance are considered: fouled condenser, charge leaks, compressor performances reduced, fans degradation, filter fouling and additional pressure drop in liquid line are explored. The over consumption due to these defects is evaluated for different building types and French climates. The results allow to define simple methods that can be used by the auditors to estimate the energy savings due to the correction of the defects.