It has been proved both experimentally and by modeling that separation of vapor and liquid is beneficial for performance of a condenser prototype with a specific separation circuiting. The prototype has an inlet in the middle of the height and separates into two flow paths after the second header. The two paths recombine upstream the exit of the condenser. This paper presents a search for optimal design for condensers with separation circuiting based on an experimentally validated steady-state condenser model. That model incorporates a mechanistic model of a flow in header to consider phase separation efficiency. Parametric studies are performed on pass circuitry, fin density and air velocity distribution. The trade-off between high heat transfer and high pressure drop for flow in the vapor path is further explained. After a design optimization, the condenser with separation circuiting shows potential for approximately 10% performance improvement compared to the baseline condenser with the same total air-side area
