Patent ID: 7104314

Claim:
A heat exchanger for transferring heat between a first fluid flow and a second fluid flow, the heat exchanger comprising: a first fluid inlet, a first fluid outlet and a first fluid flow path extending between the first fluid inlet and the first fluid outlet, the first fluid flow path having a flattened transverse cross-section with a major dimension and a minor dimension; and a second fluid inlet, a second fluid outlet and a second fluid flow path extending between the second fluid inlet and second fluid outlet, the second fluid flow path including at least two flat tubes each having a major dimension and a minor dimension, each of the tubes having at least two passes, each pass being fluidly connected to an adjacent pass of the tube through a transition region of the tube, each transition region extending beyond the first fluid flow path major dimension, the major dimension of each of the flat tubes being substantially equal to or less than the combination of the first fluid flow path minor dimension and the minor dimension of the flat tube.