Laminar, internal forced convection utilizing nanofluids is analyzed. incorporating experimentally-verified descriptions of the nanofluid's specific heat, and accounting for the dual effects of (i) increased thermal conductivity and (ii) reduced specific heat of the nanofluid relative to its base liquid. Heat transfer enhancement is quantified, and a dimensionless effectiveness is introduced to gage the nanofluid's performance relative to that of the pure, base liquid. It is shown that use of nanofluidic versions of pure liquids can either enhance or degrade thermal performance. (C) 2008 Elsevier Ltd. All rights reserved.