Calculated Results
Results update when you calculate or change scenario settings.
Shade Geometry Diagram
Calculator Inputs
Comparison Table
Manual mode compares common elevations. Automatic mode compares nearby hours.
| Scenario | Elevation | Azimuth | Profile angle | Shadow | Coverage |
|---|---|---|---|---|---|
| Calculate to generate comparison data. | |||||
Seasonal Sun Comparison
Uses the entered location and UTC offset at local noon for representative seasonal dates.
| Season point | Date | Elevation | Azimuth | Shadow | Coverage |
|---|---|---|---|---|---|
| Calculate to generate seasonal comparison data. | |||||
Understanding Awning Shade Geometry
An awning changes direct sunlight using simple geometric relationships. Its projection creates a horizontal distance between wall and edge. Solar elevation describes the Sun’s height above the horizon. Higher elevations usually push the shadow farther down the wall. Lower elevations create shorter vertical shadows for horizontal projections.
Formula used
For direct perpendicular sunlight, shadow depth follows a tangent relationship. The basic expression is S = P × tan(β) + D. Here S is vertical shadow distance below the mounting point. P represents horizontal awning projection. β is the solar profile angle. D represents the awning edge drop caused by pitch. For a pitched awning, D equals P × tan(pitch). When sunlight arrives obliquely, the profile angle accounts for wall orientation. This calculator uses tan(β) = tan(α) / cos(HSA). α is solar elevation and HSA is horizontal solar angle.
How to use this calculator
Start by selecting a calculation mode and measurement unit. Enter projection, pitch, window size, and target offset. Choose manual solar angles for quick design checks. Choose automatic mode for time and location calculations. Select the wall orientation facing away from the building. The calculator checks whether direct sunlight reaches that façade. It then estimates profile angle, shadow length, shaded area, and coverage. Required projection mode estimates awning depth for a target shade. Maximum solar elevation mode finds a threshold for your geometry.
Interpreting the results
Coverage describes the shaded fraction of the selected target height. Shaded area multiplies shaded height by target width. Heat reduction is only an approximate solar transmission estimate. It uses irradiance, shaded glazing area, and entered SHGC. Real buildings also depend on glass type and reflections. Nearby buildings, trees, recesses, and diffuse sky radiation matter. Structural sizing is outside this calculator’s intended scope. Wind loads and anchors need separate engineering verification.
Example reference data
| Solar elevation | Profile condition | Typical shade behavior |
|---|---|---|
| 15° | Low sun | Short wall shadow from horizontal projection |
| 30° | Moderate-low sun | Increasing vertical shade depth |
| 45° | Mid-angle sun | Shadow depth roughly matches projection |
| 60° | High sun | Longer downward shadow on wall |
| 75° | Very high sun | Strong vertical shade from modest projection |
Frequently Asked Questions
What is solar profile angle?
It is the effective vertical sun angle within a plane perpendicular to the wall. It combines solar elevation with the Sun’s sideways direction.
Why does wall orientation matter?
A south-facing wall and west-facing wall receive sunlight differently. Orientation changes the horizontal solar angle and effective shadow geometry.
Does awning pitch increase shade?
Usually yes. A downward pitch lowers the front edge. That edge drop adds to the vertical shaded distance.
Can I calculate sun angles automatically?
Yes. Enter latitude, longitude, local date, local time, and UTC offset. The built-in approximation calculates solar elevation and azimuth.
What happens when the Sun is behind the wall?
The façade receives no direct beam from that Sun position. The calculator reports direct-sun shading as unnecessary for that moment.
Is the heat gain estimate exact?
No. It is a simplified estimate based on irradiance, shaded area, and SHGC. Real thermal performance needs a building-energy model.
Can this calculator size structural awning supports?
No. Wind, snow, anchors, frames, and local code requirements require structural design checks.