Sumerians: Keeping cool together

The Sumerians lived about 6,000 years ago in a hot and dry climate that is now southern Iraq. Even then, they had techniques for managing the heat.

Archaeologists studying remnants of Mesopotamian cities describe how Sumerian buildings used thick walls and small windows that could minimize heat exposure and keep indoor temperatures cool.

The Sumerians built their walls and roofs with materials such as adobe or mud that can absorb heat during the day and release it during the nighttime.

They also constructed buildings right next to each other, which reduced the number of walls exposed to the intense solar radiation. Small courtyards provided lighting and ventilation. Narrow streets ensured shade throughout the day and allowed pedestrians to move comfortably through the city.

Ancient Egyptians: Harnessing the wind

The ancient Egyptians also used materials that could help keep the heat out. Palaces were made of stone and had courtyards. Residential buildings were made of mud brick.

Many people also adopted a nomadic behavior within their buildings to escape the heat: They used rooftop terraces, which were cooler at night, as sleeping quarters.

To cool buildings, the Egyptians developed a unique technology called the mulqaf, which consists of tall wall openings facing the prevailing winds. These openings act as scoops to capture wind and funnel it downward to help cool the building. The entering wind creates air circulation that helps vent heat out through other openings.

The mulqaf principle could also be scaled up to cool larger spaces. Known as a wind catcher, it is currently used in buildings in the Middle East and Central Asia, making them comfortable without air conditioning, even during very hot periods.