A heat exchanger includes an inlet plenum chamber, an outlet plenum chamber fluidly coupled to the inlet plenum chamber, and a plurality of intermediate plenum chambers disposed downstream from the inlet plenum chamber and upstream from the outlet plenum chamber. The plurality of intermediate plenum chambers includes a first intermediate plenum chamber, at least one tube bundle, and a first bypass valve fluidly coupled to the first intermediate plenum chamber. The first bypass valve is configured to control fluid flow rate from the first intermediate plenum chamber to the outlet plenum chamber.