A heat exchanger comprising: a first header (212 I) configured to receive a first fluid (F 1) and a second header (212 O) configured to output the first fluid (F 1), each of the first header and second header comprising: a tubular primary fluid channel (218 I,218 O) oriented along a first axis and having a first cross-sectional area; a first branched region (220 I,220 O) adjacent to the primary fluid channel, the first branched region fluidly connected to a plurality of tubular secondary fluid channels (222 I,222 O), each having a second cross-sectional area; and a second branched region (224 I,224 O) adjacent to each of the secondary fluid channels, each of the second branched regions fluidly connected to a plurality of tubular tertiary fluid channels (226 I,226 O), each having a third cross-sectional area; wherein the second cross-sectional area is greater than the third cross-sectional area; wherein the first cross-sectional area is defined by a first radius, r 1, the second cross-sectional area is defined by a second radius, r 2, and the third cross-sectional area is defined by a third radius, r 3; and characterized in that the relationship between the primary fluid channel and each of the secondary fluid channels follows the equation r 1 x = Σ r 2 x where x falls within the range of 1.5 to 3.5, and wherein the relationship between each of the secondary fluid channels and each of the tertiary fluid channels follows the equation r 2 x = Σ r 3 x where x falls within the range of 1.5 to 3.5; and a core section disposed between and fluidly connecting the inlet header and the outlet header; wherein each of the secondary fluid channels (222 I, 222 O), the tertiary fluid channels (226 I, 226 O), and the core have a helical geometry. a tubular primary fluid channel (218 I,218 O) oriented along a first axis and having a first cross-sectional area; a first branched region (220 I,220 O) adjacent to the primary fluid channel, the first branched region fluidly connected to a plurality of tubular secondary fluid channels (222 I,222 O), each having a second cross-sectional area; and a second branched region (224 I,224 O) adjacent to each of the secondary fluid channels, each of the second branched regions fluidly connected to a plurality of tubular tertiary fluid channels (226 I,226 O), each having a third cross-sectional area; wherein the second cross-sectional area is greater than the third cross-sectional area; wherein the first cross-sectional area is defined by a first radius, r 1, the second cross-sectional area is defined by a second radius, r 2, and the third cross-sectional area is defined by a third radius, r 3; and characterized in that the relationship between the primary fluid channel and each of the secondary fluid channels follows the equation r 1 x = Σ r 2 x where x falls within the range of 1.5 to 3.5, and wherein the relationship between each of the secondary fluid channels and each of the tertiary fluid channels follows the equation r 2 x = Σ r 3 x where x falls within the range of 1.5 to 3.5; and a core section disposed between and fluidly connecting the inlet header and the outlet header; wherein each of the secondary fluid channels (222 I, 222 O), the tertiary fluid channels (226 I, 226 O), and the core have a helical geometry.