This paper describes an integrated approach into the design and evaluation of a novel tube bundle heat exchanger that achieves higher heat transfer 1!evels at lower levels of pressure drop, while remaining less susceptible to gas-side fouling. The approach combines laboratory scale experiments with industrial observations and numerical simulations of full-scale heat exchangers to study the thermal, hydraulic and fouling characteristics of tube bundle heat exchangers. Three arrangements are compared and the advantages of the proposed novel arrangement are demonstrated. Enhanced heat transfer rates are combined with reduced pressure drop and gas-side fouling rates through careful design of the shape of the tube cross-section and reduced transverse spacing. (c) 2005 Elsevier Ltd. All rights reserved.