 Equatorial, which is Southward in the Northern Hemisphere and Northward in the Southern Hemisphere, is the best rotation for passive solar strategies because they collect much more sun during the day than they lose during at night and collect much more sun in the winter than in the summer.• The first design strategy to increase the effectiveness of Trombe Walls is painting the outside surface of the wall to black (or a dark color) for the best possible absorption of sunlight.Moreover, a selective coating to a Trombe wall improves its performance by reducing the amount of infrared energy radiated back through the glass.