In Temperatures at 100-plus degrees Fahrenheit, students at Dano Secondary School in Burkina Faso keep cool with natural ventilation. In this small market town of 11,000 people there is not much electricity to go around, so there is no air-conditioning. The schools 150-odd students travel by foot and bike from every direction in the blazing sun. Now they have refuge in a new well ventilated structure that provides a healthy environment for learning and living. The L-shaped school, designed by Architect Francis Kere is comprised of three 615- square- foot classrooms, 560- square- foot computer room, and teachers offices. Hanging over the entire structure is a single unifying piece- the gleaming wave shaped roof, made from corrugated tin and sitting on latticed rebar trusses, accompanied by long low lamella windows. These are the main components of the ventilation system bringing sweet relief from the heat. Materials include locally cut laterite, a clay containing iron which hardens when exposed to air, a fine cooling insulator.
Kere's solution for the Dano school starts with lamella window slats that can be adjusted to controll the light. Three to a room, they also draw air into the classroom. From there the split-level ceiling and roof structure takes over. Warmed from the outside, the air near the ceiling rises up and out, making room for more air to enter below. Composed of concrete and brick, the ceiling looks like inverted barrel vaulting. At the junction where each vault comes together is an opening to the roof above, consisting of a slit cut across the ceiling about eight inches wide.
The lattice then creates an open space angled to the corrugated tin above, prompting a breeze to carry off the warm air rising from within the room. When you create this physical aspiration, it takes the heat away constantly. From design to labor to construction, Kere adapts to local conditions and turns them to his advantage, assembling the truss structure for the roof on the ground in modules due to lack of crane access. Members of the community crated the school floors, pounding the earth flat with mallets and polishing with stone. With so much community involvement, this building is sure to last a lifetime.