HOW TO USE THE LOUVRE SHADING CALCULATOR

The general question addressed by louvre shading is: how much shade does a louvre system provide each hour of day, each month of the year?

A louvre system is a series of parallel louvres designed to provide shade at certain times, and admit sun at others. This tool addresses vertical louvre systems (panels), and horizontal overhead louvre systems.

The basic output of the program is a chart showing the degree of shading provided by the louvre system, for each hour of the day, for each month of the year. The entire year is depicted, so you can rapidly assess the louvre system's performance on an annual basis, and modify the inputs to achieve the optimum design. For instance, if the louvre system is providing insufficient shade, you can adjust the slat dimensions and spacing.

Note that this tool is primarily designed for use in determining window shading, although you can use it for other applications. It only provides an analysis when the sun is above the horizon, and when it's shining on the wall that the louvre system is attached to (if it isn't attached to a wall, you can pretend it is for the purpose of setting some of the inputs).

Inputs
Here are the tool's inputs. For more information, click on the name of the input on the main screen.

Louvre system type
Whether the louvre system is horizontal or vertical, and which way the slats are tilted.

Louvre depth
How deep each louvre is, in cross-section.

Louvre thickness
How thick each louvre is, in cross-section.

Louvre spacing
The on-center spacing between louvres.

Louvre tilt
The number of degrees the louvres are tilted with respect to horizontal or vertical.

Latitude
The geographical latitude of your location, 0 to 90 degrees North or South. Please use integer or decimal format for the latitude.

Show values
Whether or not the output table lists the percentage of sun or shade, in addition to using color to indicate the degree of shading.

Orientation
The compass direction the louvre system faces.

Outputs
To perform the calculation, set the inputs to the appropriate values, and click the "Calculate" button. The output table will refresh. Every time you modify the inputs, click the "Calculate" button again to see the refreshed results.

The output table has a row for each month, and a column for each hour. The colour of the cell indicates the degree of shading provided by the louvre system at that time on the 15th day of that month. A black cell indicates total shading. A white cell indicates complete sun (which you won't see unless your louvres are extremely thin and the sun is at just the right angle). Gray cells indicate the degree of partial shading. A blank white cell indicates that the sun is below the horizon. A yellow cell indicates that the sun is above the horizon, but behind (i.e, not shining on) the facade shaded by the louvre system.