Convective heat transfer in rooms

Data for convective heat transfer coefficients (CHTC's) published in the literature tend to be for anisolated heated vertical plate, with few data based on measurements at room surfaces Accurate values of CHTC's for internal room surfaces are needed for heat transfer calculations in buildings using thermal models and also for room air movement calculations using CFD models. Most existing computer models use CHTC's that have been calculated for isolated surfaces. This work presents accurate convective heat transfer coefficients for a heated wall in a room. Using heating plates attached to a wall of an environmental test chamber and by accurately measuring the surfce and air temperatures, the CHTC's have been deduced afder allowing for conduction and radiation losses from the plates. When compared with data published in the ASHRAE Handbook and the CIBSE Guide, the CHTC's values given in this paper differ by between -13% and + 20% respectively.