Evaluation of energy efficiency options for the water and air side of HVAC systems

EECCAC is an EU funded project, where twelve participants (National Energy Agencies, Manufacturers, University laboratories and Electric utilities) from eight countries gathered to identify the most suitable measures to achieve market transformation in the direction of energy efficiency of central air conditioning systems in Europe. Within the project, some energy efficiency options (EEO) have been analysed, and a summary is presented in this paper. After setting some starting points for building, climate and simulation engine, we will present the list of HVAC system EEO covered. The analysis is based on a typical office building that has been adapted to European construction habits. EEO have been grouped in air-side (AS), where we have used a constant air volume system for every EEO definition, and water-side (WS), using a fan-coil system as the basis for comparisons. WS EEO involve the temperature control of chilled water circulation loops and water transport (pumps performance). AS EEO include air transport efficiency and air handling energy saving techniques (air side economizer and exhaust air heat recovery).
Energy performance analysis is based on final energy consumption expressed in kWh per m of conditioned area and per year. Consumption is split into six different end uses: lighting, electric equipment, cooling, heating, fans and pumps, and the sensitivity to climate is studied in depth. EEO ranking is based on HVAC energy saving potentials and shows that 10% for the WS and 25% for the AS are reachable values.