An intensified desalination module directly integrating membrane distillation (MD) and solar flat-plate collector (FPC) into the same small equipment is explicitly modeled and studied in the present article. Based on a previous work applying vacuum MD (VMD) to the integrated module and the corresponding recycling system, direct contact MD (DCMD) is also adopted in similar configurations to comparatively study the dynamic performance, the impact of different parameters, and the potential production of both DCMD-FPC and VMD-FPC modules. Simulation results for a 0.35 m(2) module and a 12-hour operation show diametrically opposite performances in terms of water production and electricity consumption of these two desalination devices. Analyses on the influences of parameters indicate that the productions of both systems are limited by the incoming solar energy, and the DCMD-FPC system further suffers from conductive heat loss across the membrane. In order to relieve the performance from the restriction of available thermal energy, two approaches by heat recovery and solar concentration are applied to both DCMD-FPC and VMD-FPC to examine the potential enhancement. The results on both approaches all recommend the choice of VMD-FPC for small-scale applications, based on its more relevant productivity and less space footprint.