IIT Delhi's New AC Cuts Power Use by 1/3, Tackles Cooling Crisis

New Delhi, February 26

Researchers from the Department of Mechanical Engineering at IIT Delhi are developing a new type of high-efficiency air conditioner that has shown potential to reduce electricity use by roughly one-third, addressing concerns over rising power consumption for cooling.The health risks and productivity loss due to rapidly increasing heat stress are already reaching alarming levels. With the rise in temperature and increased use of air conditioners in homes and offices, electricity consumption for cooling is projected to triple by 2037-38, according to the India Cooling Action Plan, Report by Ministry of Environment, Forest and Climate Change, Government of India, 2019.An increase in power consumption would put stress on natural resources and lead to higher electricity bills for consumers. To address this, researchers from the Department of Mechanical Engineering at IIT Delhi are developing a new type of high-efficiency air conditioner.The research team led by Prof Anurag Goyal, which also includes Ananthakrishnan K, a PhD research scholar in the Department of Mechanical Engineering, is currently testing a laboratory-scale prototype of this proposed system, which has shown potential to reduce electricity use by roughly a third.The vapor-compression system-based ACs in use today remove humidity by overcooling the air until moisture condenses, which is a highly energy-intensive process. Prof Anurag Goyal's research group has developed a new concept that utilizes a compact add-on module to directly tackle moisture.The module uses a salt solution that absorbs water vapor from incoming outdoor air. A thin and selective polymer membrane sits between the air and the salt solution and prevents the salt from carrying over into the building's air, which is a common concern with existing liquid-desiccant systems.After the solution is diluted by absorbed moisture, it must be dried to allow continuous reuse. The team uses an innovative system integration concept to continuously revive and recirculate the same salt solution. Instead of adding a burner or an electric heater, the design uses heat that the AC already throws away through its condenser and redirects it to a regenerator module to dry the salt solution again.The system is designed to precisely match the energy transfer rate in the two parts, vapor compression and desiccant modules, across various outdoor cor the hybrid, resulting in around 33 per cent lower energy consumption, while meeting the same indoor comfort targets. Across representative Indian climates, the predicted savings range from 28 per cent to 41.5 per cent," Prof Anurag Goyal said.