Thermodynamic Modeling and Optimization of Air Handling Units

Air handling unit (AHU) is defined as a self-contained unit that the conditions of air vary while passingthrough it and reach to the desired temperature and humidity. To perform variations in weatherconditions various processes such as heating, cooling, humidification, dehumidification and mixing are applied. In this research thermodynamic modeling and mathematical optimization of air handling units approaching minimum energy consumption is achieved. The objective function for optimization is pressure drop of air crossing coil per cooling and heating load of the system. This function comprises all thermal and geometrical parameters of the coils such as coil surface area, number of rows, fin spacing and air side pressure drop of the coil. The objective function is minimized using Lagrange multipliers method. The optimization results are composed of minimum pressure drop, optimum area, optimum number of rows and fin spacing. The effects of varying the cooling and heating load, fin efficiency and the surface area of the coil on fan power consumption are investigated as well.