Cooling systems are a major energy consumer globally, accounting for about 10 percent of the world’s energy usage or 20 percent of all energy used in buildings.
With the International Energy Agency predicting a surge in cooling demand over the next 25 years, making these systems more efficient is crucial. Current air conditioners are not sustainable, and improvements are necessary as the climate crisis deepens.
A breakthrough
Montana Technologies, an engineering firm based in the US, has developed a breakthrough material, a highly porous substance called a metal-organic framework, used in its new dehumidifier system, AirJoule. This material can absorb up to 55 percent of its weight in water vapor, making it a powerful drying device.
Montana Technologies stumbled upon this new material when Shanghai’s Yutong Bus Company contacted them to help them deal with somewhat puzzling, inexplicable spikes in power consumption on certain days.
To solve this, a team from Montana Technologies was brought in, and they discovered that the buses’ air conditioning systems, which were not adequately monitored, were causing massive energy spikes due to Shanghai’s hot and humid weather.
Matt Jore, CEO of Montana Technologies, explained that the air conditioning systems had yet to be noticed. The intense use of AC to counter Shanghai’s heat significantly increased power consumption whenever the drivers turned it on. This insight prompted Jore and his team to innovate a more efficient dehumidification method, which could make air conditioning much more energy-efficient.
The AirJoule system consists of two chambers coated with this unique material. These chambers alternately dehumidify incoming air, drastically reducing the energy consumption of traditional air conditioning units. Jore claimed that AirJoule could cut energy use for dehumidification by up to 90 percent compared to conventional systems.
Montana Technologies plans to sell AirJoule components to established HVAC firms rather than creating consumer products themselves. They are also developing a system for the US military to extract drinkable water from the air, which is helpful for troops in desert conditions. AirJoule is in the prototype and testing stages, with preproduction units being built for potential customers and partners.
A different solution
Meanwhile, Blue Frontier, a competing firm, has developed a similar dehumidifying system using a liquid salt solution. This system is being installed in various locations across the US, including office spaces, warehouses, and restaurants. Like AirJoule, Blue Frontier’s system connects to secondary air-conditioning processes and schedules desiccant regeneration to times of lower electricity demand.
Centralized chiller plants are commonly used for large-scale cooling, such as in hotels. These systems draw significant power from the grid during peak times. Nostromo Energy addressed this issue with its IceBrick system, which stores calm energy in ice during off-peak hours and uses it during peak times. Installed at two hotels in California, the IceBrick system can reduce annual cooling costs by 30 percent and associated emissions by up to 80 percent by utilizing renewable energy when it is more abundant.
Traditional air conditioning technology can also benefit from better design. Gradient, a company producing window-based heat pumps, focuses on making high-efficiency systems more accessible. Their units, designed to fit into windows, offer better performance by incorporating larger heat exchangers and intelligent controls to avoid energy waste. Although currently priced at $3,800, Gradient aims to reduce the cost to $1,000 to make their products more widely affordable.
AC is a privilege and a right.
In some regions, air conditioning is a necessity. For instance, in Slovenia, where temperatures can reach 35 degrees Celsius (95 degrees Fahrenheit), efficient cooling systems are crucial for daily life and work. However, many current air conditioning units operate at only about 20 percent of their theoretical maximum efficiency, highlighting the need for improvements.
As the world warms, the demand for cooling will only increase. Therefore, it is crucial to find ways to reduce overall energy consumption for air conditioning.
Innovations like AirJoule, Blue Frontier’s desiccant systems, and Nostromo’s IceBrick offer promising solutions, but there is also potential in entirely new technologies. One such technology is “electrocaloric” cooling, which uses an electric field to induce a phase transition in materials, causing temperature changes. While still in the prototype stage, this method could one day be 20% more efficient than current systems.
Despite these advances, passive cooling measures should be considered. Simple solutions like window shutters can significantly reduce energy usage without incurring additional costs. As new technologies develop, it is essential to balance them with passive methods to achieve sustainable cooling solutions for the future.
