In a liquid desiccant air conditioning system the regenerator is one of the essential components. The effectiveness of the regenerator directly influences the system performance.

In this paper, the effects of constant, alternating and rotating magnetic fields on the laminar forced convective heat transfer of /water nanofluid (ferrofluid) in a uniformly heated copper tube are investigated experimentally. The local convective heat transfer coefficients are measured in the hydrodynamically fully developed region. The experiments are conducted using ferrofluid with 2.5% mass concentration. A quadrupole magnetic field system has been designed and constructed to generate the constant, alternating and rotating magnetic fields. For the magnetic field system, different operation modes were also examined and the most efficient mode was obtained. The effects of alternating magnetic field frequency