Students build an eco-friendly fridge that needs no power
The idea is simple, and simplicity is essential for any innovation.“ But he added: “In test models or prototypes, things are easier to do. It's different when people take a product home.“
The project by Diveesha Deevela and Anand Shankar from CMR National Public School won first prize at the regional-level science show organised by the Central Board of Secondary Education recently . It was also showcased at the nationallevel exhibition under the `renewable resources' theme last month.
The team used soil, a copper pipe, a funnel, a glass box and a steel box to create an eco-friendly refrigerator based on the principle of evaporative cooling. A suction pipe blows air into a funnel and a copper pipe takes the air through moist soil. “The air becomes cool because moist soil, since ancient times, is used to aid cooling.The air is sent into a glass chamber filled with water, where evaporative cooling takes place. The air inside the copper pipe becomes cooler and dry . The copper pipe is then directed into the storage chamber where fruits and vegetables are stored,“ Shankar explained.
The contraption brought down temperature from 27 degrees Celsius to 7 degrees Celsius. “One can store fruits and vegetables in this for 3-4 days. All it requires is watering the soil once a day to keep it moist,“ Deevela said. The principle of evaporative cooling can be used to also make an eco-friendly air-conditioner, according to Roopashree BC, a physics teacher at the school, who months to put the eco-friendly refrigerator together. In this period, three models were made, each an improvement over the previous.
“Evaporative cooling as a concept is not exactly a part of our syllabus.It involves a number of principles, such as specific heat capacity , evaporation and kinetic energy of molecules in a liquid,“ Deevela said.
The eco-friendly refrigerator, unlike a conventional refrigerator, does not release harmful compounds like guided Deevela and Shankar in the refrigerator project. “A similar concept is popular in Rajasthan, where people use clay pots to cool down temperature,“ she said.
The students spent nearly three chlorofluorocarbons. Also, its production costs Rs 1,500 as against Rs 10,000 that a conventional refrigerator would cost. “ A greater degree of cooling can be achieved if the model is scaled up in size,“ Deevela said.
On whether the model can be commercially marketed, Tarun Kumar, a senior research fellow at the IISc's Centre for Product Design and Manufacturing, said: “This is a frugal innovation that costs less. The idea is simple, and simplicity is essential for any innovation.“ But he added: “In test models or prototypes, things are easier to do. It's different when people take a product home.“
Manufacturers will have to focus on the refrigerator's embodiment -the outer cover where everything is in place, how it can be kept clean and how the soil can be kept moist.