The effect of inlet velocity for optimal revolution speed and process angle of a silica gel desiccant wheel is investigated in the present work by the help of a numerical model. This is a crucial topic that involves all Variable Air Volume systems in which off-design operating conditions need optimizing. It is found that process angle mostly depends on regeneration temperature while optimal revolution speed is strongly affected by inlet velocity, for both balanced and unbalanced flows. Switching from optimal process angle to area ratio equal to one may be an interesting solution to simplify mounting of the wheel and overall air handling units arrangement. Therefore, the effect of operating the wheel with unbalanced inlet velocities and equal area fraction is then discussed.