Shading Northern Windows
In a post about Passive Solar I talked about shading North facing windows.
That doesn’t mean installing roller shutters, or blinds that pull down over the window.
Shutters and blinds tend to make the rooms very gloomy and depressing, and with good design are unnecessary.
The best methods of shading North facing windows are:
• Overhanging eaves
• A well designed veranda
• A pergola
How Much Shade?
For areas North of Brisbane its better to have enough shade to keep the sun out of the house as much as possible.
For areas from Brisbane and South the keys are:
- Keep direct sun off the window during the summer months of; December January and February.
- Allow full sun to shine on all of the window in June July and August.
Dimensions
Keeping the summer sun out for areas South of Brisbane can generally be achieved by making sure the eaves overhang is 45% of the height (H) the shade is above the bottom of the glass.
The eaves, or other method of achieving shade, should also extend horizontally along the wall window 45% of H to either side of the window.
To minimise shading of the window in winter the shading needs to be around 20% of H above the top of the glass.
West and East Facing Windows
West and East facing windows are almost impossible to effectively shade in summer and get minimal benefit from winter sun.
Information on dealing with these windows can be found at: West and East Windows
For more Green Ideas see Sustainability