The Abu Dhabi government is evaluating demand-side management programs related to the cooling load through a series of pilots and studies. For instance, the pilot focused on the impact of optimizing maintenance of large AC systems (no capital investments) demonstrated the potential for consumption reductions of 27%. The government is developing a "comprehensive cooling plan," detailing implementation of programs.
In 2013, a Comprehensive Cooling Plan (CCP) Building and Villa Survey conducted on 1000 buildings and 200 villas found that individual building chillers provide nearly half of the total cooling capacity across Abu Dhabi Emirate; therefore, optimal chiller design and operation in the Emirate is vital to reducing energy use. Most individual chiller systems in the Emirate’s buildings and facilities use multiple rooftop air-cooled chillers.
The following five optimization measures have been found to be effective for optimizing chiller operation in Abu Dhabi:
1. Maintenance. For information on maintenance, please refer to the prescribed protocol in Appendix A-1. It is advised that facility managers try to identify and deal with problems in advance of critical maintenance issues in order to help reduce future costs.
2. System Balancing. Chilled water pumps and the flow of chilled water from each chiller should be adjusted by a qualified Heating, Ventilation, and Air Conditioning (HVAC) engineer, as needed, to ensure to proper flow throughout the building.
3. Refrigerant Charging. The performance and efficiency of any A/C system depends highly on having the correct amount of refrigerant. This measure involves evacuating and weighing the system charge and adding refrigerant, as needed, to meet system specifications.
4. Isolation. Studies indicate that many chiller systems in Abu Dhabi are designed with a much higher cooling capacity than needed to adequately cool the building. Thus, building cooling loads should be analyzed by a qualified HVAC engineer to
determine if one or more chillers are not needed.
5. Variable Frequency Drives (VFDs). Most of the chiller systems in Abu Dhabi are operated using constant-speed, chilled water pumps operating at a single speed. Operating all pumps at full power may be necessary during Abu Dhabi’s summer season, but significant savings can arise if the pumps operate at lower speeds during other times of the year. Installing VFDs to assist in pump use allows the operator to run the chilled water pumps at lower optimum speeds to maximize system efficiency.