A heat exchanger may include at least one fluid passageway adjacent a heat transfer plate and a plurality of heat transfer elements positioned in the at least one fluid passageway and joined with the heat transfer plate. The heat transfer elements may be positioned with first spacings therebetween at an inlet end of the at least one fluid passageway. The heat transfer elements may be positioned with second spacings therebetween at an outlet end of the at least one fluid passageway. The first spacings may be smaller than the second spacings.