A novel scheme of a solar assisted, liquid desiccant supported comfort air conditioning system has been proposed in this paper. The primary intent of the system is to supply air at 25°C and 52% relative humidity, even during the hot and humid summer months prevailing in the plains of sub-tropical countries like India. A mathematical model has been put forward to predict the output air temperature, humidity ratio and the effectiveness of dehumidifier as well as the regenerator. The predicted air humidity ratio has been validated against data available in the literature. The model has been used to predict the optimum mass flow rates required to achieve the desired output conditions for the selected location (Kolkata). The study thus strengthens the need and feasibility of solar assisted desiccant based air conditioning systems for the sub-tropical climates as a replacement of the traditional VCR (vapor compression refrigeration) systems.