Optimization design of the lighting and variable refrigerant flow system for the improvement of energy efficiency in existing building

Energy efficiency is the most important for reducing the operating costs and manages the electricity efficiently and indirectly will contributes the green building indices. This mean that's the significant cost savings is achieved with energy efficiency improvements, and due to continually improving equipment, lighting and air conditioning system usually provides the highest return on investment of major upgrade. Therefore, the methodology proposed are to analyses the potential of energy saving, life cycle cost and payback period of the retrofitted lighting system and mechanical ventilation system. The research done explores the effectiveness of the proposed idea through case study conducted for an existing commercial building located in Kota Bharu Kelantan. This building belongs to the federal government and functions as a Fire and Rescue Department district headquarters for the state of Kelantan. Currently, the building is using T8 Magnetic ballast type for the lighting system and normal exhaust fan for fresh air system of air conditioning and mechanical ventilation system due to budgetary cost constraint during design and construction stage. The new alternative proposed method was done by replacing the building lighting system to T8 electronic, TS and LED lamp and pre cooled of VRF System as fresh air supply to the air conditioned area. The software environment has been implemented by using Relux Suite and Diakin HKGSG as simulator in order to perform the design calculation for illumination level and cooling load. The final finding based on the output simulation results show that by implementing both the LED lighting and pre-cooled system can give the highest amount of energy saving and reasonable payback period even with the high cost of installation for the initial stage