Take advantage of solar energy

Press, 27 July 1989, Page 26

Take advantage of solar energy

Planning a new home starts with the choice of a site.

Clearly, the site should have unshadowed access to the sun at least between 9.30 a.m. and 3.30 p.m. in mid-winter. The shape of the site is less important. A site longer east-west than north-south will give you a long north wall with plenty of north-facing sun windows, but houses with clerestories or two storeyed houses can be built on differently-shaped sites.

According to a consumer guide published by the Ministry of Energy, the houses should be sited near the southern boundary to give as large and sunny a garden as possible and to reduce the

area of land which is cold and shaded most of the year.

The shape of the house should be simple and rectangular, avoiding too many projecting bays and windows which increase the heat-losing perimeter. It should be compact so that the volume to be heated is kept small. If you are planning to alter your home then it is worth considering some passive solar heating. Before starting, make sure the walls, ceiling and floors are as well insulated as possible. Add weatherstripping to all doors and windows. This will ensure that the solar heat you collect will be put to good use.

Practical solar additions to an existing home

often use existing features. Look at placing larger windows in north facing walls. Think of letting the sun deep inside by glazing a part of the roof and removing the ceiling below the glazing. If shadowing makes window collection of solar heat doubtful in winter, roof glazing may be a better solution. If the alterations include adding a room, give serious consideration to making it a greenhouse. If a greenhouse or sunspace is. the only solar heating possibility, you may overglaze it if the surplus heat will be extracted and blown into the living areas.

An added greenhouse should be provided with some heat storage — a

concrete floor, tub of water or planter beds may do. It is not always easy to add heat storage to an existing house to achieve the ideal levels.

Some people have strengthened the foundations of their homes so that containers of water could be stacked to catch the sun. If the renovations include relining the walls, some additional heat storage can be obtained in the plasterboard linings — perhaps adding an extra or thicker layer. An existing brick wall may serve the same purpose. Generally speaking, living rooms should be the warmest part of a house. Bedrooms, bathrooms and laundries can be kept a little cooler. This suggests that lounges, family rooms and dining rooms should-be on the warm, northern side of the house.

The kitchen could also be on the northern side, joining perhaps with the living areas to form one large “great room.” It should be on the east end of the house to get some advantage from morning sun and to avoid the hot afternoon sun.

Bedrooms, bathrooms and laundry can be placed ’on the cooler, southern side of a house.

Open planning of the interior helps to keep it at much the same temperature all over. A noticeable feature of passive solar homes is that they are uniformly heated throughout.

Entrance ways may be placed on either side. They can be protected from cold, prevailing winds by making them double-doored lobbies.

A well-designed passive solar home requires a properly balanced combination of north-facing sun windows and heat storage floor or walls. The size of these components must suit the climate of the site, the size of the house, the living habits of the occupants and their heating needs.