Natural convection at an indoor glazing surface

An experimental study was made to determine correlations that allow the calculation of heat transferred by convection through the window. Three configurations were studied: a hot plate; a cold plate and a window with a single-step frame placed on the wall of a room. We obtained a correlation that can be used to calculate the convection heat transfer through the window. The new correlation in the hot plate configuration differs by 14.5% from the ASHRAE correlation for laminar free convection on a vertical surface, is 27.5% from the cold plate and is 12% from the single step-frame.