In hot, dry climates, buildings made from materials with high ___________ absorb heat by day and release it at night. The Persians invented 7 ___________, which are tall structures that direct wind downwards, sometimes over water for extra cooling. In humid regions, houses on 8 ___________ allow air to flow underneath, and courtyards help regulate temperature. A more recent discovery is radiative cooling, where special white paints reflect sunlight and emit heat through 9 ___________ radiation at night. Questions 10–13: Matching Features Match each feature (A–E) with the correct description (10–13) below.
Another elegant solution is the wind catcher , or badgir , also originating from Persia. These tower-like structures rise above the roofline of a building and are designed to capture prevailing winds. Internal vertical partitions direct air downwards, often passing it over a pool of water or a qanat (an underground water channel) to provide additional evaporative cooling. Even when there is no wind, the temperature differential between the top and bottom of the tower can create a natural updraft, drawing hot air out of the building. Modern computational fluid dynamics simulations have confirmed that well-designed wind catchers can reduce indoor temperatures by up to 12°C compared to the outside. Staying Cool Naturally Ielts Reading Answers
More surprising is the use of radiative cooling , a principle that has only recently gained scientific attention but has been used intuitively for centuries. Certain whitewashed buildings in the Greek islands are not merely aesthetic; the lime-based paint reflects up to 80% of solar radiation. At night, the same surfaces radiate heat back to the cold sky, a phenomenon known as ‘night-sky radiation’. In 2017, researchers at Stanford University developed a ultra-white paint that reflects 98% of sunlight, potentially paving the way for zero-energy cooling. The oldest example of radiative cooling, however, may be the ancient Egyptians, who soaked mats in water and hung them in windows; as water evaporated, it cooled the incoming air, but the effect was enhanced by the clear night sky radiating heat away. In hot, dry climates, buildings made from materials