A heat exchanger is provided for transferring heat between a first fluid
flow and a second fluid flow. The heat exchanger includes a first fluid
flow path having a major dimension and a minor dimension and a second
fluid flow including at least two flat tubes each having a major
dimension and a minor dimension. Each of the flat tubes have at least two
passes. Each tube has a transition region joining adjacent passes. Each
transition region extends beyond the first fluid flow path major
dimension.