Almost 120 years ago, the Larkin Building in Buffalo, New York, became the first structure with central air conditioning. However, the fundamental technologies cooling our living and working spaces have seen little innovation since then. The heavy reliance on these energy-inefficient systems now threatens our health and poses a considerable environmental risk.
“In a scenario of +2-3°C global warming, air conditioning use could double in Europe and quadruple in India by 2050, potentially exacerbating climate change and placing further strain on energy grids,” states Francesco Colelli, an environmental economist and co-author of the first study to illustrate the impacts of climate change on the demand for air conditioners and electricity.
The study sought to quantify these implications by using India to project Europe's climate future and Europe to predict India's income future. The outcome suggests that the reliance on air conditioning to combat escalating temperatures over the next 22 years could lead to a rise in emissions of around 10 million tonnes of carbon dioxide in Europe and up to 120 million tonnes in India.
“On one hand, this increase in electricity is crucial for reducing heat exposure and, consequently, improving public health. However, without proper planning, this additional energy, while lifesaving, can have cost implications for the energy sector and lead to unmanageable greenhouse gas emissions,” emphasises Colelli.
While the study anticipates an increase in AC ownership from 10% to 40%, Colelli stresses that around 60% of the population will still be without the means to purchase ACs, requiring some form of thermal comfort. “This overlooked segment of the population is what we call the ‘cooling gap,’ representing millions of Indians who won't be able to afford ACs even if they desire them.”
Alternative approaches, such as enhancing the management of urban water bodies, implementing green roofs, and installing covered sidewalks, can also be practical. However, their success depends on the specific urban context and the local policymakers' decisions. Nonetheless, there are additional measures that can be taken.
More investment in low-carbon generation would also help accommodate the increased electricity demand from expanded cooling without increasing emissions. At the same time, power grids must be resilient to AC-induced spikes in demand.
During heatwaves, power outages increase due to heightened energy demand. These outages, when combined with heat waves, substantially raise mortality risks. He highlights the need to enhance efficiency: “The goal is to make the trade-off between comfort and energy consumption less significant. Assuming future AC purchases align with top-tier efficiency, electricity demand could be cut in half, so we must promote high-efficiency AC adoption.”
It is crucial to raise awareness about how actions impact energy consumption.
In urban design, addressing heat islands and urban overheating is crucial because urban areas are 4-5°C hotter than less populated areas, primarily due to buildings and heat-absorbing surfaces. Energy-efficient paints and cooling materials offer solutions to reduce air conditioning reliance. Shading and transitioning to buildings with better sun control is vital for cooling urban environments during hot summers.
Companies such as Wärtsilä are implementing strategies like programmed thermostats that restrict heating to office hours, the adoption of ceiling fans, and the transition to energy-efficient Variable Refrigerant Volume (VRV) systems for air conditioning. Almost 40% of Wärtsilä's facilities incorporate intelligent controls and metres to manage energy consumption, temperature, and ventilation.
These efforts are intended to support the company’s “Set for 30” commitment to achieving ambitious climate targets, including becoming carbon neutral in its own operations.
Although efforts are underway to enhance energy efficiency, further actions are required to transition from the energy-intensive practice of conditioning entire environments to a uniform temperature for all occupants, even when a user occupies only a tiny portion of that space.
Wilmer Pasut, Professor of Building Science at Ca' Foscari, University of Venice, is part of the International Energy Agency Annex 87 researching Personalized Environmental Control Systems (PECS). The project is exploring systems encompassing local heating, cooling, and ventilation. This includes desktop systems, chair-mounted systems, and wearables with integrated temperature control and ventilation designed for occupants' comfort.
He observes that trials have shown that significant gains in energy efficiency can be achieved with user-controlled devices, reducing the wastage associated with centralised systems. “PECS aim to disrupt traditional indoor climate control by focusing on individual comfort. Users have a Personal Comfort System in direct contact with their bodies, enabling them to make personalised temperature adjustments, delivering energy savings of 30-40% without any building modifications.”
The goal is to make the trade-off between comfort and energy consumption less significant. Assuming future AC purchases align with top-tier efficiency, electricity demand could be cut in half, so we must promote high-efficiency AC adoption.
As the environmental impact of air conditioning garners more concern, the 2024 Paris Olympics is pioneering a novel approach to ensure athletes' comfort. This includes implementing a geothermal water-cooling system beneath the Athletes Village and using insulation to further aid in preserving the cool environment, with athletes expected to adhere to guidelines like closing window blinds during the day.
This innovative approach to climate control aligns with Pasut's involvement in Cultural-E, a European project building four new Plus Energy Buildings in France, Germany, Italy, and Norway. One innovation is a House Management System (HMS) that advises residential users to open or close windows depending on the weather.
“In Italy, it's a common practice to open windows for an hour in the morning. If you have air conditioning or ventilation, this is an energy disaster in the summer and winter. Whether a building is energy-efficient or not, despite incorporating various passive solutions, largely depends on the behaviour of its occupants. It is crucial to raise awareness about how actions impact energy consumption,” he stresses.
This perspective on energy efficiency highlights the contrast between the reluctance of designers, architects, and engineers to embrace change, driven by the fear of financial repercussions, and the market's demand for faster adoption of new technologies. Pasut says, “This year, we launched a pioneering university program in Environmental Engineering for the Ecological Transition, focusing on these emerging technologies. We aim to raise the next generation of designers capable of integrating these innovations into building practices.”
