Mech/Elec ALS Lesson Two - Comfort, Climate and Solar Design: Solar Plot and Intensities

Solar plot = path of the sun plotted onto a grid (either circular or rectangular)

Shadow mask = representation of the shading devices plotted onto the same grid for comparison.

Circular graph = draw hemisphere over the site, solar plot is the sun's path on that hemisphere, shadow mask comes from masking all of the angles which are obscured by the shading device (or trees or other buildings, etc.

Radial lines = azimuth lines

Concentric circles = altitude lines

For more information, See http://ecotect.com/archive/ click "sun-path diagram" in the menu .

Solar Intensities

the sun's intensity per square foot varies depending on the angle between the wall and the solar vector.

Solar vector = a line drawn to the sun's position

Direct normal intensity (Idn)= the highest intensity that occurs when a hypothetical receiving surface is perpendicular to the solar vector. This intensity varies with the time of day, early morning is lower intensity since sun has to pass through more atmosphere.

There will tend to be a large variation in the solar intensity on a given wall orientation for a given time of day.

time: 0.75, 5:40-6:00, 6:50-7:15pm, 6/14/09