With its interactive user interface, the Solar Tool makes the process of accurately sizing and positioning overhangs, shading devices and louvres easy. This tool helps architects, planners and building services engineers who need to consider the extent of solar penetration into buildings, overshadowing or the most appropriate means of shading a window.

The program uses a flexible, parametric model on which can be placed any number of horizontal, vertical and detached shades. You can select any date, time or location, seeing immediately the resulting shadows. As well as being able to interactively manipulate the size and shape of the model with the mouse or enter the parameters directly, you can choose to automatically optimise the size of any shades over any range of dates and times you require.

Screenshot of the Solar Tool showing interactive sun-path diagram and 3D model view side-by-side.

The resulting displays feature both shading and solar penetration as well as sun-path diagrams, sun angles, shade dimensions and solar tables.

Sun-Path Display

Sun-path diagrams are a 2D representation of the annual movement of the Sun through the sky. Both stereographic and orthographic diagrams are available. In the one diagram, the designer can quickly determine both the direction and time of any solar event throughout the year.

Stereographic Projection

In form, stereographic diagrams can be likened to a photograph of the sky, taken looking straight up towards the zenith and through a 180° fish eye lens. The path of the sun at different times of the year is then projected onto this flattened hemisphere to give the blue date and hour lines shown here.

Othographic Projection

An orthographic projection is simply a 2D graph of the Sun position in cartesian coordinates. The azimuth is plotted along the horizontal axis whilst the altitude is plotted vertically. Reading the Sun position is simply a matter of reading off the two axis.

Solar Tables

In this mode, solar position information is displayed as a table of hourly values for the current day, starting at sunrise and stopping at sunset. Both local and solar times are shown along with global azimuth and altitude values, relative horizontal and vertical shadow angles and, if you have calculated the shading table, shading percentages.

Interactive 3D Shading Model

To calculate overshadowing and shading percentages, SunTool uses a simple 3D model of a window set into a wall. You can change the dimensions and orientation of this model interactively with the mouse or manually entering the parameters in the panel provided.

Window and Shading Model

SunTool uses a simple single-window shading model. If you need to analyse shading on more complex surfaces, see the ECOTECT software. You can place any number of horizontal and vertical shading devices on the window, at any angle and spaced off at any distance. You can even quickly design a solar pergola to fully exclude summer sun whhilst allowing in warming winter sun.

External Shades

In addition to window shades, you can also add external detached shades to simulate surrounding buildings, trees and other obstructions. For simplicity of manipulation, these are defined as rectilinear blocks of any height, width and offset from the window.

Interactive Nodes

All aspects of the shading model are interactively editable using dragable nodes. Simply click on the element or shade you want to edit and a series of red interactive nodes will appear. Togglable tooltips and statusbar messages keep you informed of each parameter's effect. Shadows and shading patterns are also updated in real-time as you drag.

Draggable Sun Path

You can also choose to overlay the path of the sun through the sky on the selected date. This is also draggable, automatically updating shadows and shading in real time. Hold the Control key down and you can interactively change the date.

Linked Windows

Both the diagram window and the 3D model are inter-linked. Change the date or time by dragging in the sun-path disgram and the shadows update in real-time in the 3D model. Change the orientation of the rear wall and the overshadowing pattern in the sun-path diagram will automaticallly update. This will greatly enhance your understanding of shading effects.