SOLAR ANALYSIS - Internal Sun Penetration

Displaying Shadows

This is a brief tutorial, explaining the process of displaying shadows (and reflections) on specific objects in a model. In this instance it is used to illustrate the effect of sun penetration inside a space.

1. Open  Sun Penetration.eco  from the Tutorial Files directory located in your main ECOTECT Install directory.
   
   There five separate zones in this model, one for the room and the rest for different window elements.
   
   This model has been drawn to accurately access the penetration of daylight into the space, including the thickness of the front wall. It is not an appropriate model for attempting thermal or acoustic analysis, as the room has been divided into zones for different types of elements.
   
   
2. To display shadows select the Shadows item from the display menu, hit F10 on the keyboard, or from the Shadow Settings control panel click the Display Shadows button.
   
   
   
   The default settings for shadows is to cast them on the ground (Z = 0).
   
   It is also possible to set shadows to fall on specific objects which are tagged as shaded, this is explained in the next section.
   
   ECOTECT has an overall shadow and sun patch colour which can be set in User Preferences under the Modelling tab.
   
   It is also possible to set specific shadow and reflection colours for different zones in a model, which is useful for highlighting different parts of a model. This is done in the Zone Management dialog box.

Displaying Internal Shadows

To display internal shadows it is necessary to tag some walls as shaded objects. This tells ECOTECT to only display shadows on specific objects and not on the ground.

1. Using the Select tool, select the floor and western wall of Zone 1, as shown below.
   
   You will need to hold down the Shift key to add the second object to the selection set. If at first you cannot select the object you want, use the Space bar (even when holding down the Shift key) to cycle through objects which share the same line segments.
   
   
2. With the two objects selected, either;
   
   from the Modify menu go to the Assign As sub-menu and choose Shaded Surface;
   
   or, right click the mouse in the Drawing Canvas, go to the Assign As sub-menu and choose Shaded Surface;
   
   or, from the Shadow Settings control panel click the Shaded button in the Tag Object(s) As section half-way down.
   
   
   
   This should result in a display similar to that shown below.
   
   
3. Now that shadows are displayed on the floor and wall, it is possible to cycle through the date and time to show the effect of the windows and shades at different times of the year.
   
   This is easily done via the Date/Time toolbar.
   
   
   
   Either; type in a specific value using the keyboard (remember its a 24 hour clock);
   
   or, click the up/down arrows with the mouse, to adjust the time by 15min. intervals, and the date in weeks;
   
   or, use the Page Up/Page Down keys on the keyboard, once either input box has the focus.
   
   In conjunction with the above methods, use the;
   Shift key to adjust in larger increments;
   Control key to adjust in smaller increments;
   Home key to jump to the beginning of the day/month/year;
   End key to jump to the end of the day/month/year;

Displaying Reflections

To display internal reflections, it is necessary to tag some objects as reflectors. In this case the objects are the horizontal planes making up the light-shelf. As reflections will occur on the ceiling and the walls, we will need to change the objects tagged as shaded.

1. Using the Select tool, select the ceiling and western wall of Zone 1, as shown below.
   
   Once again, you will probably need to use the Shift key and Space bar.
   
   
2. Next select the four light-shelf objects, as shown below.
   
   
3. With the four objects selected, either;
   
   from the Modify menu go to the Assign As sub-menu and choose Solar Reflector;
   
   or, right click the mouse in the Drawing Canvas, go to the Assign As sub-menu and choose Solar Reflector;
   
   or, from the Shadow Settings control panel click the Reflector button in the Tag Object(s) As section half-way down.
   
   
   
   The display will change to look similar to the following:
   
   
   
   With both shadows and reflections displayed, it can be a little confusing so we will temporarily turn off shadows.
4. Select the Show Reflections Only option in the Shadow Display group in the Shadow Settings panel.
   
   
   
   This should result in the the following diagram.
   
   
   
   With this display, you should be able to change the date to cycle through the year in order to work out just how deep the reflection will penetrate into the space.
   
   You may wish to experiment with the angle of the reflectors to try to maximise penetration whilst minimising direct sun penetration.