Super-Efficient Air Conditioning Technology Slashes Energy Costs

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As average temperatures rise, the demand for air conditioning systems will rise as well. According to the latest study sponsored by RMI — formerly known as the Rocky Mountain Institute — air conditioning today accounts for nearly 20 percent of the electricity consumed by buildings worldwide. By the end of this decade, RMI expects cooling of indoor spaces will become the second largest factor driving up the demand for electricity. Only demand to power battery-operated vehicles will be greater.

If the world continues to use the cooling technologies available today, air conditioning systems worldwide will put enormous stress on the electrical grid and be responsible for more than 100 gigatons of CO2 equivalent emissions by 2050 — double today’s annual global emissions. Addressing this challenge is a matter of human health, comfort, and equity, and is crucial for our ability to adapt to the changing climate, RMI says.

India is already the world’s fastest growing air conditioning market, and the projections suggest that nation will have more that one billion room air conditioners in operation by 2050, increasing its electricity demand for cooling nine times compared with the year 2022. “Widespread adoption of current AC technology could jeopardize both the power grid and the environment, RMI says. Therefore, India has an urgent need and a great opportunity to be a pioneer in the innovation of cooling technologies.”

In late 2018, a coalition led by RMI, the Indian Government’s Department of Science and Technology, and Mission Innovation launched the Global Cooling Prize. This competition had a bold and ambitious goal to develop an affordable residential cooling solution with five times lower climate impact because of a combination of greater energy efficiency and lower global warming potential refrigerants than the typical units sold at the time in India.

The Global Cooling Prize For Air Conditioning Technology

In 2021, the Global Cooling Prize challenged the cooling industry to identify the best possible residential cooling technology. The winning designs successfully demonstrated prototypes that had a climate emissions impact that was five times less than conventional cooling equipment in use today. In addition, the newer equipment delivered greater comfort at a significantly lower cost over the useful life of the equipment, thanks to highly efficient components optimized for managing humidity and using Earth-friendly refrigerants.

These super-efficient A/Cs use many times less energy than conventional products and have the potential to substantially reduce peak demand and neutralize the climate impacts that will invariably occur if India continues using conventional cooling equipment.

The results show that in real-world conditions, super efficient ACs used 60 percent less energy than typical AC units, while reducing peak demand and enhancing occupant comfort. The study also uncovered critical gaps in current testing standards — particularly with respect to how cooling equipment performs in high-humidity conditions. The current testing standards underestimate the real-world energy use of air conditioning equipment in warm and humid climates largely because of how conventional cooling equipment attempts to control humidity. Testing revealed that up to 25 percent more energy is used just to manage humidity in conventional units.

Air conditioners primarily cool the air through what is called  “sensible cooling,” which lowers the air temperature. They also dehumidify the air in a process called “latent cooling.” However, air conditioners are primarily designed to manage temperature, not humidity, and their dehumidification capabilities are limited. Most of their energy input goes toward sensible cooling, leaving very little energy available for latent cooling. This energy allocation is largely fixed, leaving users little ability to improve the balance between cooling and dehumidification. As a result, today’s ACs are inefficient at managing humidity, leading to either discomfort or high utility bills for people who live in hot, humid locations like India.

The tested units were required to achieve a target temperature of 27° C (81° F) and 60 percent relative humidity. The field testing also established the limitations of the current testing standard and highlighted how units that are optimized to achieve higher performance rating have much higher energy use in the field than what is predicted by these standards today. The testing proved that adopting super-efficient ACs will enhance occupant comfort, decrease energy usage, reduce peak demand, and lower greenhouse gas emissions.

Saving 400 Gigawatts

Allowing super-efficient ACs to successfully commercialize and access the market could reduce India’s peak load by approximately 400 gigawatts in the year 2050 — equivalent to India’s total installed power capacity today. This would significantly reduce pressure on power grids, save $380 billion in new infrastructure investments, and support India’s climate goals.

But this impact is not just limited to India, the report says. Super-efficient ACs also present an opportunity to change the trajectory of global energy use and emissions. Deploying super-efficient ACs for the 3 billion additional AC units expected to be installed worldwide by 2050 would avoid 68 gigatons of cumulative emissions. To put that into perspective, that is more than current total annual emissions. We are talking about a major impact on emissions and demand for electricity over the next 25 years.

However, this transformation will require government leaders, policymakers, manufacturers, and large buyers to unite and demonstrate their leadership at this critical juncture to drive change. By setting new test standards and performance rating systems, fostering market demand, and taking actions to improve affordability, India can unlock the potential of super-efficient ACs. These actions are key to improving lives, strengthening grid resilience, and addressing the climate crisis.

Bringing these technologies to scale requires rethinking how we define and measure performance. The report makes a compelling case for updating efficiency standards and accelerating early adoption of super-efficient ACs through procurement and demonstration efforts. It helps to raise the awareness of key stakeholders such as government leaders, policymakers, AC manufacturers and industry players, and financial institutions. Obtaining their support for the development, commercialization, and adoption of super-efficient air conditioners in India and globally is critical to keeping the Earth habitable for hundreds of millions of people.

The enormous economic, grid resilience, and climate benefits India and the world stand to gain from commercializing super-efficient A/C equipment and making it accessible to people is clear. By doing so, we can provide access to cooling for all, without further warming the planet.

A Vicious Circle

Most of us can see what is happening here. The Earth is getting hotter, which will drive up sales of air conditioning equipment. More air conditioners mean more electricity will be needed to run them all. Despite the most fervent hopes of CleanTechnica readers that all new electricity will come from non-polluting renewable energy sources, we know that won’t be so. Jackasses like Chris Wright, the current US Secretary of Energy, are running around screaming the world — especially Africa — will need many more coal-fired generating stations in order to meet their future needs. More thermal generators powered by coal or methane will make the world even hotter than it already is, which will drive up demand for air conditioning even more.

This isn’t news. We wrote about it more than 6 years ago. But it’s a vicious circle, one that will feed on itself in perpetuity unless we find a way to break the feedback loop and inject some sanity into humanity’s penchant for self destructive behavior. The Global Cooling Prize is an important tool for doing precisely that. A parallel is the development of more efficient heat pumps, which can both heat and cool our living spaces.

I had dinner recently with someone who slammed heat pumps because they don’t work below 40° F and cost more to run than using good old fashioned city gas. I was a little surprised to hear this and asked a few questions. It turns out his experience was from 20 years ago, so while his characterization was correct for that period of time, it is not relevant to modern heat pumps.

The policy implications of that must be considered by RMI and all others promoting new air conditioning technology. There are billions of people using A/C units today who will tell you they don’t work all that well and are expensive to run. It takes a long time to change people’s minds. As Mark Twain so famously said, “What you don’t know won’t hurt you near as much as what you do know that t’ain’t true.”

Today, only one company is manufacturing air conditioning equipment that uses the latest high efficiency technology. That means there is a long, long way to go yet. It’s time to get started.