Heat transfer is examined for channel flow of mixed convection between two parallel plates with two hot blocks within. The numerical method SIMPLE-C is used. The influence on flow field and heat transfer capacity with respect to elevations of two hat blocks is investigated. The elevations of and distance between hot blocks are varied in an attempt to understand their influence on mixed convection. The Reynolds, Richardson, and Prandtl numbers are also varied in order to study the influence on flow field and temperature distribution. It is observed that heat transfer capacity increases as the distance between two hot blocks increases. For different arrangements, to make heat transfer of the second hot block be independent of the first, the distance varies. However, such distances can be reduced dramatically with a staggered arrangement. The heat transfer capacity increases effectively with increasing Reynolds number. Heat transfer and flow type are greatly affected by various fluids.