Several correlations have been used in recent years for the purpose of calculating convective, centre-glass heat transfer rates across gas-filled interpane window cavities. These correlations are examined and their background discussed. The most recent experimental data are gathered and presented. These data were used to develop a new correlation specifically for the purpose of window analysis. The new correlation is not restricted to conditions customarily encountered in window applications (i.e., low Rayleigh number, high aspect ratio). It also is valid with respect to applications involving low aspect ratio (i.e., windows with wide pane spacing or narrow spacing with muntin bars) and/or applications involving high Rayleigh number (e.g., wide pane spacing, krypton fill gas).

KEYWORDS: year 1996, convection, heat flow, vertical, windows, glazing, calculating, double glazing