Methods and apparatus for exchanging heat

A method for exchanging heat between a first fluid and a second fluid. The method includes providing a heat exchanger having a stack of at least two layers of support structures, wherein each support structure layer is formed from a lattice of support members, and substantially fluidly separating the at least two support structure layers using at least one barrier such that each layer defines a fluid passageway. The method also includes directing a flow of first fluid through a first of the fluid passageways, and directing a flow of second fluid through a second of the fluid passageways that is adjacent the first fluid passageway to facilitate exchanging heat between the first and second fluids.