South African homes are built with virtually no regard to thermal efficiency at all. We are spoilt by our marvellous climate and thus don’t give much thought to the issue of building insulation when building or purchasing a home. However some parts of the country do experience short periods of quite intense cold during the winter. Consequently many of us simply freeze in winter whilst consuming huge amounts of energy trying to heat homes that were never designed to be thermally efficient. The same applies to cooling homes in areas which are subject to very high temperatures or humidity in summer.
We don’t tend to run our heaters constantly during winter because our poorly insulated homes would waste too much energy and the cost would be exorbitant for most. We tend to switch heaters on when we get home from work for example. Heaters which rely on radiation, such as the ubiquitous gas heater, are thus often the best choice for our life styles because they can deliver heat to a room very quickly after being switched on.
In colder regions of the world, such as the USA and Europe, the modern heating trend is towards under-floor radiant heating in which the entire floor (not just the area above an electrical heat pad embedded under the tiles or carpet) is heated, usually via circulating hot water, which makes the floor a source of constant gentle radiant heat. This relies on the floor slab being designed or modified specifically for this purpose and being heated to a relatively constant temperature for a longish period of time (e.g. most of winter). Under-floor radiant heating is considered to be one of the most efficient methods of heating a home. There are various different means of heating the water used in these systems, the most energy efficient being a geothermal heat pump, which unfortunately is not widely available in South Africa. Solar water heating is one potential method which is quite relevant to our country.
Surviving a Power Failure
Electrical heaters are clearly no use during a power failure. Supplying alternative electrical power to electric heaters is quite a daunting exercise because of the large amounts of power required. A powerful generator is normally the only practical option.
Another answer is switch to other forms of energy such as gas, coal or even wood if the local by-laws permit. Gas is a good option which is commonly used provided it is readily available.
A more environmentally responsible option is solar water heating for an under floor heating system. Alternatively a heat pump could be used to heat the circulating water.
Energy Saving Tips
There are no short cuts to using less energy to heat or cool your home, the only real answer is to improve the insulation. The best starting point is installing under roof and ceiling insulation (hot air rises, so a large amount of heat is lost through the ceiling).
From an architectural point of view, large expanses of glass, and double volumes dramatically increase the amount of energy required to heat a home. A single sheet of glass is a very poor form of insulation, whilst double volumes require a lot of energy to heat because all the hot air rises up to the distant ceiling. Unfortunately these are architectural features which many of us find appealing. Perhaps the answer is not to try and heat those parts of the home in winter and rather contain the heating to smaller rooms that have smaller windows. Alternatively investigate double glazing or adding thermal films to those huge windows!
Suitable Alternative Sources of Power
Gas heaters are very effective and commonly available in many different forms. They are a viable alternative to electrical heating systems. However, most forms of gas such as LP (liquid petroleum), or natural gas are derivatives of oil and thus their price is linked to the oil price which has displayed a constant upward trend over the last few years.
Solar Water Heating: South Africa is blessed with one of the best climates in the world in which sunny days are by far the norm rather than the exception even during winter in many regions. Solar water heaters can be used to heat the circulating water for under floor heating systems. As with all applications of solar energy, this results in a permanent reduction in demand on the country’s electricity capacity as well as a reduction in your energy bill.
Generators: Of course virtually any requirement for alternative electricity power can be satisfied using the appropriate generator.