Virginia Beach Roofing: Article About Passive Solar Window Design
In a typical house, windows are evenly allocated on all four sides or in spots that give the best views without regard to energy efficiency. An alternative layout involves strategically placing the windows according to passive solar home design concepts. A homeowner interested in passive solar home design concepts should consult a Virginia Beach roofing and exterior specialist.
Passive solar home design takes advantage of the predictable movements of the sun to harness its natural heating and lighting power. Selecting appropriate window types and locations is an important facet of passive solar building design. Windows should be designed so that the sun heats the house during winter, doesn't overheat the home in summer and provides ample indoor illumination. Using the power of the sun efficiently saves money on heating, cooling and lighting expenses.
In order to use passive solar design ideas, it is important to understand the geometry of the sun throughout the seasons. The sun appears to travel in an arc, rising in the east and setting in the west. In the winter, the sun is low in the sky relative to the horizon. The sun moves in a high path through the sky during the summer.
Expert roofers from Jayhawk Exteriors of Virginia Beach VA would be happy to answer any question you have about roofing, gutters or windows.
In the northern hemisphere, the sun lies in the southern half of the sky, so the south facing wall of a house receives the most sunlight.
To utilize the sun's heating capability, windows should be placed on the south side of a house. In the winter, the low sun's energy enters southern windows and naturally heats the house. During the summer, the sun is high in the sky, so south facing windows should be shaded by overhangs or other methods so that the house does not overheat. North facing windows do not get direct sunlight, so they should only be used for lighting. Sunlight is difficult to control on the east and west sides of the home, so windows on these sides should be shaded or have a low solar heat gain coefficient (SHGC).
In cold climates, most of the window area should lie on the south facing wall of a house. A south facing window should have a high SHGC of 0.60 or greater to maximize the amount of sunlight that passes through. A U value of 0.35 or lower ensures that the window is well insulated and will not allow significant heat to escape. In hot climates, north facing windows are preferred, and south facing windows should have abundant shade. Windows in hot climates should have an SHGC below 0.55 to reduce air conditioning costs. The U value is not as important in hot regions, so a U value of 0.40 or less should suffice.