The present study has been conducted improvement of flow path in heat exchanger for using effective heat transfer area. The original model had problems which didn't have uniform distribution of fluid flow in heat exchange area. So the heat exchange area was used partially because of different fluid velocity passing through the heat exchanger. We designed splitters to distribute the fluid flow uniformly in front of heat exchanger. The splitters showed improvement of flow distribution and that result would expect to get improvement of efficiency of heat exchanger.