A multiunit plate-type direct contact membrane distillation module (MUDCMD), which assembles multiple DCMD modules into one module, is proposed and studied by theoretical simulation and experiment for desalination applications. The multiunit design gives a more compact module with an increase in production rate. The reverse-order assembly of units makes possible the use of narrower channels and the increase of permeate flux relative to the single unit module.. The use of Channels with inserting carbon fiber separators results in a higher permeate flux compared to the use of an empty channel. Correlations of Nusselt number for both the carbon-fiber-filled channel and the empty channel have been obtained from the experimental-results and theoretical model. The effectiveness,of the carbon-fiber-filled channels was evaluated in,terms of the ratio of relative increase of permeate flux to the relative increase of power consumption. The effectiveness of the carbon fiber separator with a 2 mm open slot is higher than the one with a 3 mm open slot in the compact multiunit module.