Use of Under Floor Air Distribution (UFAD) System for Energy Saving Assessment

Heating Ventilation and Air Conditioning (HVAC) systems are used to maintain the thermal comfort and indoor air quality (LAQ) of an indoor environment. With the recent experience of contagious fatal air borne viruses, the requirement of controlling the $LAQ$ of buildings has become utmost important. HVAC systems of buildings in hot and humid climates are responsible for $ 50\%-60\%$ of the total building energy consumption. Air distribution system supplies the processed air to the occupancy zones and exhausts the return air. There are three main air distribution systems and are: conventional Orerhead Air Distribution (OH.AD) systems, Traditional Displacement Ventilation (TDV) systems and Underfloor Air Distribution (UFAD) Systems. Although the UFAD systems have many advantages over the conventional systems according to the configuration, UFADs had not been adopted in to practice due to lack of research investigations to convince the clients, designers and contractors to incorporate and install these systems in buildings. Therefore, this paper investigates the temperature distribution, air speed variation, Draught Rate (DR), Percentage of Dissatisfied (PD) and temperature effectiveness characteristics of UFAD systems from a validated Computation Fluid Dynamics (CFD) model CFD results proved that the thermal comfort and localized energy performance of UFAD systems are higher than that of the conventional TDV systems.