Why we need environmentally-friendlier air conditioners?

Published: January 11, 2022

Air conditioners are a sign of luxury and comfort. One many think we should use more of as a last resort option. According to various studies, air conditioners will soon become as common as mobile phones. By 2050, there will be more than 4.5 billion air conditioners using 13% of electricity worldwide producing 2 billion tons of carbon dioxide. Greenhouse gas emissions from air conditioners will account for a 0.5-degree increase in the global temperatures, according to the World Economic Forum.

By 2030 over half of the world’s population will live in hot climates and will have increased exposure to dangerous heat conditions. Consequently, the demand for air conditioners will rise. By 2050, the residential cooling demand is expected to increase by 300% globally, and 5 times the current level in developing countries.

The current air conditioners have managed to reach only 14% of maximum theoretical efficiency, with most air conditioners only achieving just 8%. The reality is our aircons are not as efficient as we believe them to be.

As the climate crisis looms on us, the race is on to make air conditioners more eco-friendly. The Global Cooling Prize aims to do just that.

Global Cooling Prize

The competition, launched in 2018, is initiated by the Indian Department of Science and Technology, part of the Indian Ministry of Science and Technology; the Rocky Mountain Institute, and Mission Innovation. The aim of this competition is to produce efficient residential air conditioners that will:

• Have at least 5 times less climate impact than air conditioning units on the market today
• Prevent up to 100 gigatons of CCO2-equivalent emissions by 2050
• Mitigate up to 0.5˚C of global warming by 2100
• Enhance living standards for people in developing countries

According to RMI estimates, if the technology were rapidly deployed, it could prevent up to 100 gigatons of CO2-equivalent emissions by 2050.

What’s the problem with the current air conditioners?

We are still using the technology developed by Willis Carrier in 1902. The air conditioning system works on the vapour-compression cycle. In this technology, a liquid refrigerant flows through the coils changing its state from liquid to gas under varying pressure. As the refrigerant turns to vapour, it gets cold and cools the indoor metal coil. A fan blows over the cold metal coil delivering cool air indoors. The refrigerant condenses on reaching the outdoor coil and releases heat outside.

In humid climates, the indoor coil has to be really cold so that the water droplets condense as air blows over the cold metal coil. That means that the aircon will have to be set to colder temperatures to produce the desired cooling effect. This means that we end up wasting energy and paying more for utility bills.

The challenge for the innovators is to reduce the electricity use and utilise climate-friendly refrigerants. Refrigerants have a high global warming potential, for example, R32 has a GWP of 675 and R410-A has a GWP of 2088. It means that 1 kg of R32 is equivalent to 675 kg of carbon.

Eight teams have been chosen as the finalists in the Global Cooling Prize. Some inventors are taking the approach of making climate-friendly refrigerants and reducing electricity usage by integrating solar panels. Kraton Corporation, M2 Thermal Solutions and Barocal are some of the finalists who have ditched refrigerants altogether to achieve drastic results. During the field testing, multiple teams have met or even exceeded the Prize’s climate impact and operational criteria.

The results are expected to be announced on the 29th April 2021.

The technology however needs to be scaled up extremely quickly - hit the market by 2022 and capture 100% of annual sales by 2040, according to RMI. The other major challenge would be to keep costs so low that low-income earners can afford the new and climate-friendlier aircon.

We may have to wait a couple of years before we can buy the aircon. Meanwhile, we can do our bit by not using air conditioners for long durations, setting up the temperature 1-2 degree higher than required and getting the unit serviced regularly to improve its efficiency.

References

• https://www.anthropocenemagazine.org/2020/07/the-race-is-on-to-build-an-ac-unit-that-doesnt-cook-the-planet/
• https://globalcoolingprize.org/
• https://www.theguardian.com/environment/2019/aug/29/the-air-conditioning-trap-how-cold-air-is-heating-the-world