This paper examines coupled heat and mass transfer in porous media where natural convection is caused by temperature and concentration differences. Two alternative non-dimensional models are developed and used to correlate the experimentally measured heat transfer across a porous medium. It is shown that a parametric model correlates the data well with a general form. Nu∝(Ra Da N)0.295 Ja-0.45. The other model, based on the analogy between heat and mass transfer, is less accurate in predicting heat transfer but the results are good enough to suggest that such analogy models could be used in a wide range of heat and mass transfer processes. The effect of bed geometry on the two models is also discussed.