If thermal energy source like solar or waste heat with even low temperature (between 50°C and 80°C) is available, solid desiccant air conditioning system is an alternative solution to substitute the conventional vapor compression refrigeration air conditioning for tropical climate region. A pilot scale Solid Desiccant Coated Heat Exchanger-Dehumidifier (SDHED) integrated with dew point evaporative cooler has been developed and experimentally investigated on its performance under tropical climate. A number of experiments were carried out to determine the optimal operation parameters of the system depending on the weather condition (outside air temperature and humidity ratio) and availability of waste heat grade (regeneration temperature). The experimental result shows that the optimum COP is achieved when the switching time, i.e., dehumidification/regeneration time, is 300 seconds.