[ti:Scientists: Chemical Used in Air Coolers Needs Replacing]
[al:Science & Technology]
[ar:VOA]
[dt:2023-10-19]
[by:www.voase.cn]
[00:00.00]Jennifer Byrne owns a heating and air conditioning repair company in the American city of Philadelphia, Pennsylvania.
[00:12.92]Air conditioning, or AC equipment, cools the air in a home.
[00:20.84]To do this, the equipment uses a gas called a refrigerant.
[00:27.07]While working on AC equipment in a house, Byrne puts gas from the equipment into a special container.
[00:37.58]The gas is known by an industrial name: R-410A.
[00:44.04]Scientists say it traps 2,088 times more heat in the atmosphere than carbon dioxide.
[00:54.87]Because chemical refrigerants capture heat, some people say they need to be replaced with something else. 
[01:05.48]Some scientists are worried that the release of methane, carbon dioxide, and other gases is making the atmosphere warmer.
[01:17.47]The Clean Air Act bars businesses from releasing refrigerants into the air on purpose. 
[01:26.13]Some companies are trying to find replacement gases that trap less heat, which might work almost as well.
[01:35.71]Leaking AC equipment in homes is one way the gases get into the atmosphere.
[01:43.84]Cars are another source of these pollutants, said Eckhard Groll.
[01:50.37]He is an expert in refrigeration and head of mechanical engineering at Purdue University in the state of Indiana.
[02:01.31]He said AC units in cars can leak.
[02:05.76]He said that, on average, about 25 percent of refrigerant from all cars leak out every year.
[02:17.20]There are more than 200 million gasoline cars in the U.S. alone, Groll said.
[02:24.58]Using those numbers, Groll said he estimates about 45 million kilograms of refrigerant is leaking into the atmosphere each year.
[02:37.22]Supermarkets are the second-largest source of leaks.
[02:42.80]Long pipes carry refrigerant to coolers that store food.
[02:49.29]Danielle Wright is head of the North American Sustainable Refrigeration Council, a nonprofit group based in Mill Valley, California.
[03:00.22]It supports cleaner methods of cooling.
[03:03.47]Wright said the average supermarket leaks about 25 percent of its refrigerant each year.
[03:12.31]That number is based on a U.S. Environmental Protection Agency report from 2005.
[03:20.59]She criticized supermarkets, saying "...it's cheaper to leak the refrigerant than to build a leak-proof system."
[03:28.94]Limiting leaks is important because the refrigerant can be reused. 
[03:35.81]Many businesses recycle refrigerant gas. 
[03:39.58]One such company, A-Gas, was founded in Britain in 1993. 
[03:47.38]The company has several centers in the U.S.
[03:51.81]Refrigerants can be used many times over and can last for 30 years, said Mike Armstrong, President of A-Gas in the Americas.
[04:02.79]The company takes in refrigerants and containers from around the U.S. and other countries. 
[04:09.48]It processes the gas to be sold and used again.
[04:13.86]He said his business is doing well.
[04:17.65]"This industry is probably going to increase four to five times in the next couple years," Armstrong said.
[04:25.78]The chemical industry is also looking for a chemical to replace R-410A. 
[04:33.88]Some researchers have suggested carbon dioxide itself as a possibility.
[04:40.83]But Groll of Purdue University said that carbon dioxide has to be under high pressure to work as a refrigerant.
[04:53.40]Completely different equipment would be necessary.
[04:57.49]Christopher Cappa teaches environmental engineering at the University of California, Davis.
[05:07.19]He said carbon dioxide would be useful "if we're pulling it out of the atmosphere." 
[05:14.57]But he added, "if we're producing it just as a refrigerant, that wouldn't be necessarily nearly as good."
[05:24.30]Wright of the Sustainable Refrigeration Council supports the use of carbon dioxide.
[05:31.83]"This is kind of a low-hanging fruit, it's a known technology and it's market ready," she said.
[05:39.17]However, she said that reducing leaks from air conditioners is more difficult.
[05:45.43]She said chemical and equipment manufacturers and existing building rules have slowed the growth of new refrigerants in the U.S.
[05:56.47]But one manufacturer, Trane Technologies, said it has been working hard on different choices.
[06:03.97]Trane says it has a refrigerant that is 78 percent less damaging to the environment than the current one.
[06:11.99]The company says it will start using it in its equipment beginning in 2024.
[06:19.23]And at Harvard University, researchers are working to develop a solid refrigerant instead of a gas. 
[06:27.87]Jarad Mason, an assistant professor of chemistry and chemical biology at Harvard University, is working on the project.
[06:39.45]He said he is hopeful about using solid materials because they could be used in both large buildings and normal homes.
[06:49.44]"Demands for heating and cooling are only going to increase," he said.
[06:56.15]He added that researchers must find ways of cooling that do not harm the environment and are not costly.
[07:06.32]I'm Andrew Smith. And I'm Jill Robbins.