Cool roofs in Africa to avoid heatstroke

In Africa, thousands of people die every year from heat waves, partly because many homes have tin roofs that catch fire when temperatures rise and become vectors of heat-related illnesses and deaths. An effective response is represented by:  cold roofs (In English cool roofs) can significantly reduce heat inside buildings, and in many parts of Africa this can help reduce the risk of heat-related illnesses and deaths. Their operation is very simple, yet equally effective.

 A white roof or one with a special reflective coating absorbs much less solar energy than a dark roof made of sheet metal or concrete (these are the most common in African countries), which can reach temperatures between 60 and 80 degrees, unlike a cold roof that can keep the temperature in the house between 20 and 30 degrees. The operation is simple: instead of absorbing the sun's radiation and converting it into heat, the roof tries to reflect it outward and release any heat it absorbsIn homes without air conditioning, which are common in many African countries, this can result in a reduction in internal temperature of several degrees Celsius.

During heat waves:

• decreases the risk of heat stroke and dehydration;
• the elderly, children and people with chronic diseases are less exposed to dangerous internal temperatures;
• improves sleep, which can be seriously compromised during very hot nights;
• Those who work or rest at home during the hottest hours are subjected to less thermal stress.

Even a reduction of 2–5 °C Internal temperature control can be important when outside temperatures exceed 40°C and cooling systems are not available.

Projects for the widespread installation of cool roofs have been implemented in Africa, in countries such as Rwanda, Nigeria, Kenya, South Africa, Ghana

In these cases, universities, governments, and international organizations are evaluating how reflective roofs can reduce the internal temperature of buildings and improve people's comfort.

The limitations of cool roofs are that they do not eliminate the problem of extreme heat: they work mainly during the day and are less effective if the nights remain very hot; in very humid climates, the benefit may be less than in hot, dry areas; They perform best when combined with roof insulation, natural ventilation, tree shading, and building design suited to the local climate.

Read also: 

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