Natural convection in enclosures is extensively investigated due to its importance in many applications, such as heat transfer through double glazing windows, electronic cooling devices, geophysical applications, etc. Two configurations that have been extensively explored in the literature are the differentially heated enclosures and the Rayleigh-Benard problems. In the present work, a different kind of problem is investigated, namely the cross thermal boundary conditions. Three dimensional analyses were performed for an enclosure cooled from below with one vertical wall heated, and the other connecting walls were assumed to be adiabatic. The thermal condition at the ceiling is varied from an adiabatic one to a different degree of heating. The objective of this study is to simulate the comfort provided by floor cooling in a room. For comfort requirements, the interest is on determining the rate of heat transfer and the temperature distribution in the room. Also, the results have importance for other cooling applications such as electronic cooling and natural convection in freezers. Furthermore, the problem is academically interesting for understanding the fundamentals of natural convection. Based on the authors' knowledge, the physics of this problem has not been explored by other people in such a detail. However, the application has been in practice from ancient times. The predicted results are interesting and have practical applications. For a certain configuration, where strong three dimensional recirculations were predicted, the flow is three dimensional, hence the two dimensional assumption is not valid. Also, it is found that the rate of rate transfer from the floor is a weak function of the investigated parameters, such as Rayleigh number. (c) 2005 Published by Elsevier Ltd.