DESIGN & PROPORTIONAL COMPUTATIONAL ASSESSMENT BETWEEN A CONVENTIONAL AND CIRCULAR DUCT SYSTEM

The successful operation of any air-conditioning system is dependent upon the sufficient circulation of air in the air-conditioned space. The careful estimation of the pressure losses is necessary for the selection of proper duct size. The duct cost in air conditioning system is 20 to 30 % of the total cost of the equipment's requirement and power required by the fan contributes the substantial part of the running cost. It is, therefore, necessary to design an air duct system for least capital cost & lowest running cost of the fan. Duct design is the design of pipes which convey conditioned air and then distribute it to different spaces according to the requirement. The advantages of well designed and constructed interior duct systems are numerous. Among these advantages are improved energy efficiency through the elimination of duct leakage to outside and the elimination of conductive heat gains/losses. This paper focuses on a study of design and modifications air cooling duct using Computational Fluid Dynamics (CFD) analysis considering all air flow features relating to the duct system efficiency. The need for optimizing duct design especially to provide improved flow conditions. It combines theoretical and software-enabled tools to provide a detailed comparative analysis of the costs and benefits involved in selecting a particular shape (rectangular or circular) of duct for a prescribed situation. The focus of this paper will be on using CFD software tools to study velocity distribution of air in the duct at various sections, pressure difference at various outlets and distribution of air flow for different load conditions.