July marked the hottest month ever recorded in human history, with heatwaves shattering temperature records across the globe. While the discomfort of excessive heat is undeniable, the consequences extend far beyond discomfort. Severe heat is the deadliest weather event, surpassing floods, tornadoes, and hurricanes combined in terms of annual fatalities in the U.S. As climate change intensifies, access to cooled spaces is evolving into a vital health necessity and a fundamental human rights issue.
However, conventional air-conditioning systems have ensnared society in a detrimental feedback loop: as temperatures rise, the demand for air conditioning increases, leading to higher energy consumption and greenhouse gas emissions. “We’re trapped in a vicious and accelerating cycle,” remarks Nicole Miranda, an engineer specializing in sustainable cooling at the University of Oxford. Cooling has become the fastest-growing contributor to energy consumption in buildings, with projections indicating that global demand for cooling will triple by 2050 if the current trajectory continues. This surge equates to an additional 4,000 terawatt-hours of energy consumption, equivalent to the entire annual energy usage of the United States.
It is evident that existing air-conditioning technology, in use for nearly a century, cannot effectively combat climate change. Innovative solutions are essential to provide efficient cooling to a growing population while minimizing environmental impact. A significant challenge lies in the refrigerant chemicals used in current AC systems, many of which are potent greenhouse gases. Although some initiatives aim to replace these refrigerants with eco-friendly alternatives, the bulk of AC emissions, around 80 percent, arise from energy consumption.
One approach to break the cycle is to decouple the dehumidification and cooling processes that are typically intertwined in standard AC systems. This separation prevents excessive cooling and overuse of energy. Some emerging AC designs employ desiccant materials to remove moisture from the air before cooling it, recycling the heat generated in the process. Start-ups like Transaera are developing systems that claim to consume 35 percent less energy than traditional AC units.
More significant efficiency gains can be achieved through the combination of dehumidification and evaporative cooling, eliminating the energy-intensive vapor compression process used in conventional ACs. Evaporative cooling relies on the principle that the transition of water from liquid to gas absorbs heat. Innovative AC devices incorporate hydrophobic barriers to perform evaporative cooling while controlling humidity. This approach can achieve up to 75 percent greater energy efficiency. Additionally, some companies, such as Blue Frontier, are trialing systems that combine desiccants with evaporative cooling, potentially reducing energy consumption by 50 to 90 percent.
Despite these promising innovations, the transition from testing to market adoption remains a multi-year process. Barriers such as higher manufacturing and installation costs, industry inertia, and policies favoring cheaper systems may hinder the widespread adoption of new cooling technologies. Moreover, enhanced efficiency alone may not offset the anticipated increase in air-conditioning demand due to rising temperatures.
To build a cooler and sustainable future, passive strategies based on urban planning and building design must complement technological advances. Incorporating green spaces, water features, shading, optimized building positioning for natural airflow, and retrofits for improved insulation and reflective panels are essential components of holistic cooling solutions. Cooling is a multifaceted challenge that requires a combination of better buildings, smarter cities, advanced technology, and a comprehensive understanding of the broader environmental impact of air conditioning.
By Impact Lab