Residents of the hottest state in the country use some of the highest rates of air conditioning to keep their homes at livable temperatures. But cranking their AC could be making the Sunshine State even hotter.
The energy used for cooling releases carbon dioxide into the atmosphere, contributing to global warming. In other words: Cooling creates heating, which requires more cooling, which creates more heating. It’s a vicious cycle, said Patricia Kio, a University of Florida architecture/sustainability professor. But Kio and other researchers say solutions are out there to cut the industry’s emissions and slow that cycle.
People need AC to live a healthy life in Florida, she said. That means finding new ways to make AC sustainable, a vision where a cool and comfortable lifestyle aligns with a healthy planet, too.
Nearly 90% of U.S. households use air conditioning in some form, according to the Energy Information Administration, whether that’s central AC via air ducts or some kind of wall or window unit. In Florida, it’s 96%. The state ranks third for the most energy consumed for cooling per household, behind Arizona and Louisiana.
All of that cold air creates a paradox. The electricity that feeds cooling, mostly produced by natural gas in Florida, fuels emissions that then cause warming temperatures.
On average, a Florida household nearly doubles the AC-related carbon emissions of the average U.S. household, according to the Energy Information Administration. That’s about 3.5 metric tons of carbon dioxide per Florida home each year — the weight of about 1,400 bricks. It adds up to 27 million metric tons annually if all AC-equipped homes in the state fell within the average, and 12% of the state’s total carbon emissions across the board as of 2023.
But AC is a necessary service, Kio said. It prevents heat-related deaths across the globe. She thinks the way AC is built — and reused — can be changed to decrease emissions and waste.
Kio specializes in circular economies, an economic model for industries to reduce their environmental impact by using one another’s waste. She researches how scrap building materials can be repurposed for new structures, looking into their durability.
“We’re always thinking to add more to what we have,” Kio said, “but how do we use less, and still remain sufficient?”
She believes this concept could be applied to AC in Florida.
As more efficient systems are developed, old ones that release greater emissions must be scrapped — but it takes emissions to build the new systems too. If the waste from old metals and plastics can be reshaped into a more modern AC unit, emissions from both making and operating the unit can be cut down simultaneously.
Using recycled materials could also lower the production costs for more modern units, and the affordable price tag could encourage use, Kio said. So far, applying a circular economy model to cooling in Florida is conceptual, she said.
Across the ocean, however, research and action on circular cooling are already in motion.
Giovani Palafox-Alcantar has been studying circular cooling at the Oxford Smith School, founded to blend business and sustainability research. He’s head of executive education and specializes in sustainable cooling.
“Cooling is essential for comfort, for survival, for humans in hot climates,” Palafox-Alcantar said. “But often they waste resources, or they use lots of energy, and they contribute to climate change.”
The AC manufacturing industry could be more efficient across several different areas, he said. Currently, units are hard to take apart for reuse, or to repair or replace individual parts. Separating plastic from metal at the end of a unit’s lifespan is difficult and costly. But if manufacturers altered their designs, companies could recover useful materials, Palafox-Alcantar said.
Researchers call this a “cradle to cradle” approach, where materials can be reassembled over and over into new units to fully reach their potential. Smartphones work this way — someone can trade in their old phone so a company can recycle its parts. The company usually also gives the customer a new phone at a discounted price.
With vast increases in the need for AC in tandem with global warming, cradle- to- cradle styles of recycling could save both a customer and a company money, Palafox-Alcantar said.
Materials could even be used for cooling methods other than AC. For example, insulation in old, inefficient and broken AC units can be recovered and sold to construction companies building more energy efficient houses that need it in the walls.
Another circular economy approach that could help make the industry more sustainable is called “cooling as a service.” Instead of people owning their own individual AC units, companies would own them, operate them and circulate chilled water and refrigerants to businesses and households all at once. Cooling would operate like utilities, billed at a steady rate. Companies would be responsible for powering and upkeeping the AC units.
“Creating a service could significantly reduce the financial barriers for small businesses and households,” Palafox-Alcantar said. “Companies retain ownership, which means they want systems that are efficient and last longer.”
One of the biggest issues surrounding AC emissions is outdated tech and cheap materials ruling over the industry, he said. People opt for the less expensive option when they select an AC unit, which often is the least energy efficient.
But if companies were in charge of cooling as a service, they would be motivated to invest in better tech in need of less repair and less overall cost to run. They would want a longer lifespan out of an AC unit too. They might also be motivated to lobby for cheaper energy, like solar, to become more mainstream, he said.
“[Cooling as a service] can dramatically increase efficiency, and that comes with reducing costs and increasing accessibility,” he said. “Using it in places like the city of Miami, or other big places, local governments can explore their solutions for sustainable development.”
The problem isn’t implementing it, Palafox-Alcantar said. There’s a bigger mindset problem, both in his home country of England and the U.S.
“The greater virus that I can think of are cultural attitudes,” he said. “There is a widespread perception that usually newer is always better, and it discourages repair, which leads to premature disposal of equipment.”
A few things could make circular cooling in Florida a good idea, said S.A. Sherif, a UF engineering professor and founding director of the university’s HVAC Laboratory. Florida’s large population size could help accelerate a transition into a more efficient economy for it, because the market would be big enough to sustain it, he said.
In at least one way, Florida is far more sustainable than other states. Overall, heating contributes more to climate change than cooling does, Sherif said. In 2022, energy used for heating produced four times the carbon dioxide emissions that cooling did across the globe. Heating often requires more extreme temperature control, jumping a home sometimes 40 to 50 degrees higher than the outdoors in winter. Cooling usually has to do less work, lowering temperatures by a couple dozen degrees.
Florida’s AC industry overall is moving toward solutions, Sherif said. Solar energy powered cooling and climate-friendly refrigerants are among the major changes helping clean up the A/C industry in the state, he said. There’s still room to grow, though.
“California is leading the nation towards a more sustainable economy,” Sherif wrote in an email. While Florida may lag behind, it is heading in the right direction. “It is on a more sustainable path.”
