When inventor Ashis Paul of Bangladesh came up with an innovative way to draw cool air into homes using plastic bottles, his whole company got on board to help teach
people living in rural Bangledesh to do the same. Since February this year, they have helped people to install these units in more than 25,000 households in developing areas of the country.

To make an Eco-Cooler, you cut plastic bottles in half, mount them on a board and place the board over a window, with the bottlenecks facing the inside of the house. The change in pressure that occurs when air enters the wider part of the bottle and comes out through the bottleneck cools the air. The Eco-Cooler doesn’t require any electricity to function. It can decrease the temperature by 5°C, from 30°C to 25°C.

The Grey group decided to make and distribute these units for free. They teamed up with Grameen Intel Social Business Ltd. to distribute the Eco-Coolers. The raw materials are easy to find: the streets are littered with bottles. People are shown how to make the Eco-Coolers and asked to make them on their own and to teach others.