A heat exchanger may include a gas conduit flowable through by a predetermined gas and a heat conduit flowable through by a predetermined fluid compound working fluid. The heat conduit may be in thermal communication with the gas conduit. The heat exchanger may include a first section having a first section length, a second section having a second section length, and a third section having a third section length. The gas conduit may span, in a direction of flow of the gas, the first section, the second section, and the third section. The heat conduit may span, in a direction of flow of the working fluid, the third section, the first section, and the second section. The first section may include a gas inlet and the third section may include a working fluid inlet and a gas outlet. The section may include a working fluid outlet.