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Passive solar heat

To utilize solar energy, you can use all kinds of complicated 'active' systems, involving pumps, pipes, collectors and boilers full of water. But you can also achieve the same results 'passively', in any home that has a wall (more or less) facing southwards. Ideally, you'd take this into account when building your home, orientating your home's living quarters southwards, thus creating greater possibilities for 'catching' the sun, especially in the winter. The following illustrations speak for themselves.

If L : H = 1 : 1.5, then from May 12th to August 1st the shadow is 100% in the afternoon.
If L : H = 1 : 1.8, then on June 21st the shadow is again 100%.

No matter how vital the sun is for us, we try to keep sunlight out of our homes on hot summer days, and this can be done very successfully with a large roof overhang, which will keep out the
'high' summer sun yet lets in the 'low' winter sun.



We are then faced with two possibilities: We can let absorbed infra-red radiation heat the floor, which is made of dark colored or dark gray/black tiles and is insulated from below, or, we can let it be warmed in another way, by using a wall made of the same materials and covered by glass sheets: a so-called 'Trombe wall'. Such a wall is ideal for homes located in areas where there is often strong wind and in homes that have many draft-producing windows and glass doors.



In our region, a house is ideally positioned if it faces southwards. There should be lots of windows on the southern side of the house, in order to let in as much sunlight as possible. A windflower will indicate how much efficiency is lost, according to the degree in which a home deviates from facing southwards.


A greenhouse located on the sunny side of the house catches lots of heat in the autumn and winter and distributes it to the rest of the house. The roof specifically, but also the greenhouse walls, must be screened in summer (ideally on the exterior, using a blind) to prevent the interior from becoming too warm. A tree could eventually be planted on the southern side, the shade from the tree helping to cool the interior in summer. But select a species of tree that loses its leaves early in the autumn, so that you can extract the maximum natural benefit from the sun.