Heated glazed wall

A glazed wall comprising:

• a sealed double pane inside glazing positioned facing the interior of a room for which the glazed wall forms an exterior wall;
• an outside glazing positioned facing an outside environment which may be at low temperature, said inside and outside glazings forming a space through which outside air can circulate past the inside glazing for discharge into the room;
• means for circulating outside air through said space comprising a frame for said outside glazing, the frame for said outside glazing having an opening below said outside glazing, and a frame for said inside glazing, the frame for said inside glazing having an opening above said inside glazing;
• electrical heating means formed of a transparent conducting layer positioned within the double pane glazing for heating one pane of said inside glazing, said conducting layer on a pane of said double pane glazing facing the room, whereby heat is transferred by conduction to the air circulating in the space;
• a low radiation emissivity layer, formed of a transparent semiconducting fluorine doped SnO2 having a thickness of 420 nm, on a face of the other pane of said inside glazing opposite that facing the interior of the room, whereby radiative heat transfer to said outside glazing is reduced;
• and
• a spacer filled with a dehydrating agent positioned between the panes of said inside glazing.