Consumers were spared, and the state’s power grid was relatively unscathed from a record-breaking hot day. Still, as the temperature around the world increases, more people need to install air conditioners. But AC units, as sold today, could exacerbate global warming: They draw tons of electricity from the grid on hot days, and their chemical refrigerants accelerate global warming.
That’s why researchers and beginners Hoping to create new, cutting edge AC units. AC technology has only seen incremental improvements over the past 100 years, said Ankit Kalanki, managing director of Third Derivative, a climate technology accelerator co-founded by energy think tank RMI. “There hasn’t been a step change in creativity.”
The good news is that companies are rushing to develop more efficient ACs. The question is whether they will be ready in time.
Global demand for air conditioning is expected to increase significantly over the next few decades. According to the International Energy Agency, the number of AC units worldwide will reach 5.6 billion by 2050, up from just 2 billion units at present.
But unless air conditioning efficiency improvements are made, all these ACs will put an unprecedented strain on the electricity grid. Air conditioners and electric fans already account for about 10 percent of electricity consumption. AC efficiency decreases on very hot days, because the units have to work harder to move heat outside the home. During a heat wave, millions of people come home and turn on their AC at once, between 4pm and 9pm, when air conditioning can account for 60 to 70 percent of electricity demand, and shake up grids like California’s.
Meanwhile, a key component of modern air conditioners – chemicals known as refrigerants – have been in the atmosphere for decades. ACs work by exposing liquid refrigerant, a chemical with a low boiling point, to warm indoor air. That heat causes the refrigerant to evaporate into a gas, cooling the air. A compressor then turns the refrigerant into a liquid and repeats the process.
The problem is that refrigerants can come out of air conditioners, both when they are in use and, normally, when ACs are thrown away. Early ACs were mostly made of chlorofluorocarbons, or CFCs, which were one of the first real global climate concerns, the hole in the ozone layer. CFCs were phased out in the 1987 Montreal Protocol, an international agreement to combat the depletion of the ozone hole, and were eventually replaced by hydrofluorocarbons, or HFCs.
But HFCs have their own problems – they are thousands of times more powerful greenhouse gases than carbon dioxide in the short term. Amendments to the Montreal Protocol will phase out HFCs significantly by the mid-2040s. In the meantime, they are still contributing to global warming.
There are many ways to make existing AC technology more efficient. Some newer AC units use a different refrigerant, such as R-32, which has a lower global heat capacity than other hydrofluorocarbons and uses less energy to compress, saving electricity. Other units use a technology known as “variable speed compressors” that allows the unit to operate at different settings. The compressor can speed up if it’s 100 degrees F and swell, or slow down if it’s only 85 degrees. This helps to save electricity and utility bills.
And more advanced models are just around the corner. Kalanki is one of the leaders of an initiative called the RMI Global Refrigeration Award, which rewards manufacturers who can produce at least affordable AC prototypes. five times It is better for the climate than the current models. Two companies that received the award are Green Electric Appliances and Daikin Industries. Both used traditional vapor compression technology, but with improved refrigeration and clever designs they could change the response to outdoor temperatures.
Other companies, startups, and researchers are investigating whether they can eliminate vaping altogether. A startup called Blue Frontier uses a liquid that absorbs moisture from the air and stores it in a tank to regulate temperature. According to the company, this system saves up to 60 percent of the electricity required to run ACC services throughout the year. And a team of Harvard University researchers have developed a prototype air conditioner they call Cold SNAP. The prototype does not use a refrigerator, but uses a special coating on the ceramic frame to evaporate water to cool the indoor space without adding moisture to the air. “Because we don’t have the vapor compression system and the energy to try to release and compress the refrigerants, the energy consumption of these systems is much lower,” said Jonathan Greenham, one of the project participants.
What to look for when buying
Some of these new designs may take years to reach the market, and when they do, they may still be more expensive than conventional ACs. But in the meantime, there are still many options to buy a more efficient AC unit. “There are technologies that are two to three times more efficient than the most common ACs on the market today,” said Kalanki. The challenge is that adoption is very low. Most consumers are only looking at the sticker price on an air conditioning unit, and overlook the fact that buying a more expensive unit upfront can save them money in the long run.
When considering an AC unit, he recommends buyers look at three things: the type of refrigerant used, the efficiency level, and whether or not the unit has a variable-speed compressor. Those metrics could tell consumers that their units could cost them thousands of dollars in electric bills and add too much to the problem of climate change.
Finally, the government should set strict performance standards for air conditioners all of them ACs on the market – not just the high-end ones – are efficient and safe for the planet. “There are rules to prepare the floor for air conditioners,” he said. “But that floor is a little too low.”
