Facility managers must ensure that the A/C unit chosen is of the correct size and rating, has the appropriate motors, and is maintained on a regular basis. Thermostats (e.g., programmable, digital) should be installed in the building to control the indoor temperature throughout the day during different seasons.- Electricity savings of up to 3% can be achieved for every degree increase in the set-point temperature.- Studies have verified that a thermostat setting of at least 24°C. can provide an optimal balance between occupant comfort and energy efficiency.- Thermostats should be programmed to adjust the temperature, including increasing the temperature in unoccupied areas and returning to the "normal" temperature sufficiently prior to occupancy to condition the space for comfort. Typical maintenance procedures, including checking the refrigerant levels, cleaning and/or replacing the air filters, and cleaning the condenser coils, should be conducted routinely. The efficiency and life of the motor can be improved by re-filling the lubricants, checking the tightness of any belts, replacing any broken parts, and ensuring that all electrical connections are tight and insulation is not worn. Ensure Cooling Unit Efficiencies (including Energy Efficiency Ratios (EERs) or Coefficient of Performance (COP)) are optimal and meet the UAE and Abu Dhabi Government's (QCC, Estidama, ESMA) standards and requirements. Periodic and preventative maintenance of cooling systems is vital for maintaining low electricity bills and maximizing energy reductions. Maintenance is needed for all cooling systems. Periodic maintenance should occur on at least a quarterly basis, depending on the type of system being operated for the building. Frequency of maintenance can range between monthly, quarterly, bi-annually, and annually depending on the type of system and it's location. It is recommended that, during Abu Dhabi's peak summer months (June through September) maintenance on A/C systems be conducted on a monthly basis, as A/C unit performance tends to deteriorate more rapidly due to increased use and the higher temperature and humidity levels in the ambient environment. Conduct routine maintenance.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 - i.e., "System Balancing".The performance and efficiency of any A/C system depends highly on having the correct amount of refrigerant. Refrigerant levels should be checked periodically by a qualified technician to ensure that they are according to the manufacturer's specifications.Building cooling loads should be analyzed by a qualified HVAC engineer to determine if one or more chillers are not needed.Install Variable Frequency Drives (VFDs) to optimize chilled water pump operation. Conduct re-commissioning and retro-commissioning activities (planning, investigation, implementation, verification, and hand-off) periodically (semi-annually, annually, or seasonally) to address any issues that have occurred over a building's lifetime. Optimize cool air distribution systems. Efficient lighting retrofits should be completed prior to A/C modifications to ensure that A/C potential is maximized and quantified accurately.