Shading Calendar | University of Idaho Integrated Design Lab

Analysis Parameters

Idaho City

…or upload an EPW / TMY3 / TMYX file

Click to select a weather file

Building Type / Balance Point

Custom T_b (°F)

Temperature Units

Overlay

Min. solar gain to flag shading: 120 W/m²

Select an Idaho city or upload a weather file to generate the shading calendar.

Shading Calendar

Cool (≤ 65 °F)

Comfort (66–79 °F)

Hot (≥ 80 °F)

Night (sun below horizon)

Shading needed — darker = more solar gain

Shading Analysis

Fixed vs. Operable Shading

Brown & DeKay distinguish two shading regimes based on the symmetry of the sun's path around the summer solstice. Sun angles that need shading on both a spring date and its mirror fall date (same sun geometry) can use fixed shading devices (overhangs, fins). Angles that need shading on only one side of the solstice require operable shades (deciduous trees, retractable awnings).

Method (Brown & DeKay, Sun, Wind & Light, 3rd ed., Technique A26): A cell of the 12-month × 24-hour calendar shows the mean dry-bulb temperature for that month and hour over the typical meteorological year. A cell is flagged as requiring shading when (1) the mean temperature exceeds the building's balance point T_b, and (2) the sun is above the horizon at that hour (computed from solar geometry at the city's latitude/longitude, with longitude- corrected solar time). Three reference balance points are provided per Brown & DeKay: outdoor rooms (65 °F, 18.3 °C), skin-load-dominated buildings (55 °F, 12.8 °C), and internal-load-dominated buildings (45 °F, 7.2 °C). Color bands of ≤65 / 66–79 / ≥80 °F follow the textbook convention; the diagonal hatch overlay marks the cells where the building requires shading given the selected T_b.