ENERGY CONSUMPTION AND FEASIBILITY STUDY OF A HYBRID DESICCANT DEHUMIDIFICATION AIR CONDITIONING SYSTEM IN BEIRUT

This work studies the economic feasibility of integrating a rotary solid desiccant wheel with the conventional vapor compression air-conditioning system in the city of Beirut. To increase the economic practicality of such a hybrid system, the combined system utilizes the heat dissipated by the condenser and natural gas heat energy in regenerating the desiccant wheel. A heat and mass transfer desiccant model is developed to study the hourly performance of the hybrid system when used in air conditioning a typical auditorium (150 m(2)) over the entire cooling season. The economic performance of the hybrid system is compared with the conventional air-conditioning system while varying the number of occupants in the auditorium from 10 to 100 to change the sensible heat ratio from 0.53 to 0.27 and the percentage of the outside fresh air from 25% to 100%. The conventional system cooling load range was between 9.2 kW and 63.4 kW for the cases simulated in this work, while the vapor compression subsystem varied in the hybrid system from 7.4 kW to 32.7 kW. It was found that the economic viability of the hybrid system increases with lower sensible heat ratio (SHR) and increases in the percentage of outside air. The payback period varied from two years for a high occupancy system to seven years for a low occupancy system.