Useful solar gains through a glazed south-facing wall in the U.K. climate

A glass skin attached to a southfacing wall may serve to direct a sizeable fraction of the solar gain absorbed at the outer surface of the wall to the wall interior. The heat flow may help to make good ventilation heat losses, and conduction losses to other parts of the building. A wall of high thermal resistance tends to restrict this flow, but it also restricts the outward flow of heat. For given conditions there may be an optimum thickness. Tables are presented giving the heat needs for an unglazed wall, and for a wall with one or two glass skins attached to it. The variation in heat need with choice of month, ventilation loss and comfort temperature is shown as a function of the wall resistance. The results are based on weather data for the north Wirral, U.K. 53.4° N.