Abstract: A heat exchanger used for wind tunnel temperature control applications. The heat exchanger is a finned tube design with each tube aligned perpendicular to the wind tunnel flow direction but with the tube bundle aligned at an oblique angle to flow direction for increased surface area. Tube fins may be aligned with the bulk flow direction. The heat exchanger is built in modules with horizontal splitter plates separating each tube bundle. The benefit of this heat exchanger design for wind tunnel applications is the combination of low pressure loss and favorable heat transfer performance in a compact design, while maintaining flow quality consistent with stringent test requirements.