Roof Overhang Shading

Because the sun travels different paths across the sky in the winter low and summer high time an overhang can be constructed to utilize and manipulate the heat energy from the sun.

Roof overhang shading.

The following snips show shading at noon on april 16 june 21 september 1 december 1 and february 1. In the first case the overhang is simply too big for the home. For example if the roof s overhang does not shade the window during the hottest hours of the day direct and reflected sun light will heat the interior. How roof overhangs or other window overhangs work to control heat and solar gain.

In passive solar home design exterior roof overhangs provide a practical method for shading building elements such as windows doors and walls. That might be desirable during winter months but very uncomfortable during hot summer months. Overhangs are most effective for south facing elements in the northern hemisphere and at midday. An overhang or some sort of solar control or solar shading is a crucial element in passive solar design because it blocks the sun s heat energy when it is not desired.

You may use wide overhangs and verandas in hot climates without a cold season and in hot wet climates with high levels of rainfall but oversized overhangs in other. For hot dry climates with some heating requirements gradually increase the overhang up to 50 of height full shading. Shade each data cell has the percentage of shade listed in addition to the background color as an indicator. The roof overhang does not extend far enough.

The shade is in 1 increments. The sun is in 1 increments. For hot humid climates and hot dry climates with no heating requirements shade the whole building at all times with eaves overhangs of 50 of height from floor level to both north and south where possible and use planting or adjoining buildings where it is not possible. No i just made the overhangs wide enough to provide the extra shade.

A value of 73 for example indicates that the overhang is shading about 27 of the window area and 73 of the window is in the sun. The roof overhang is too wide. The depth of roof overhangs is crucial in cold and moderate climates where oversized overhangs will have negative side effects. Overhang depth for solar heat gains and shade.