In many parts of the world, the cool blast of an air-conditioner on a hot day is increasingly seen as a necessity rather than a luxury. Climate change is driving this shift, pushing average global temperatures upwards. As the world warms, the demand for air conditioning (AC) is set to soar, with estimates suggesting a near tripling of room-cooling ACs by 2050. While this expansion promises to save lives, improve livability in cities, and boost economic productivity, it also comes with a hefty environmental cost.
The electricity powering air conditioning is already responsible for more carbon dioxide (CO2) emissions than the entire aviation industry. And as temperatures climb, the energy required to cool spaces intensifies, creating a vicious cycle of increased energy demand and rising emissions. This poses a significant challenge as the world grapples with mitigating climate change.
Fortunately, a wave of innovative technologies is emerging to address this problem. These advancements are focused on making air conditioning more efficient, less reliant on harmful refrigerants, and better integrated with existing energy infrastructure.
One key area of focus is dehumidification. While air conditioners cool air, they also remove moisture, which is a significant drain on energy. Research has shown that nearly a third of the energy used for air conditioning is dedicated to dehumidification, and this proportion is expected to increase as the world experiences higher humidity levels.
To tackle this challenge, companies are exploring novel approaches. Transaera, a Massachusetts-based startup, is leveraging metal-organic frameworks (MOFs) – molecular cages that can trap and release water molecules – to create a coating that absorbs moisture from incoming air. This system is designed to reduce energy consumption by up to 40% compared to traditional air conditioners.
Trellis Air, another innovative company, is investigating selectively permeable membranes to filter air, potentially reducing the need for active cooling and achieving a cooler feel with less energy expenditure.
Another critical area for improvement is refrigerant use. Hydrofluorocarbons (HFCs), commonly used in air conditioners, refrigerators, and heat pumps, are potent greenhouse gases with warming effects significantly higher than CO2. Leakage during a unit’s lifetime and emissions from discarded units contribute to significant environmental harm.
Companies are actively pursuing alternative cooling technologies that minimize or eliminate the need for refrigerants altogether. Blue Frontier, a Florida-based company, has developed a system that uses a liquid desiccant, similar to ultra-salty brine, to remove moisture. This approach leverages the cooling effect of evaporating water, reducing energy consumption by 50% to 90% and significantly cutting the environmental impact of refrigerants.
Moreover, this technology offers the potential for flexible energy use, allowing the desiccant to be recharged at night when energy demand is low, and minimizing strain on power grids. This is crucial as widespread, synchronized air conditioner use during hot weather can lead to severe electricity spikes, potentially causing blackouts, particularly in developing countries with weaker grids.
To address this challenge, some companies are exploring innovative approaches to managing energy demand. Nostromo, an Israeli company, has developed “IceBricks” – units containing frozen water capsules that can store energy during low-demand periods and release it during peak cooling periods. This system is designed to reduce cooling electricity costs and lessen carbon emissions, promoting more efficient and reliable energy use.
The future of air conditioning hinges on a continued commitment to innovation and collaboration. By embracing these advancements and pushing the boundaries of engineering, we can achieve cooler climates without sacrificing the health of our planet.
