As a partner of Climate Group, Saint-Gobain is pleased to share this article with the Climate Week NYC community. It was originally published in Constructing a Sustainable Future, a magazine that is part of the Sustainable Construction Observatory launched by Saint-Gobain to accelerate sustainable construction worldwide by rallying all stakeholders in the sector's transition.
There are currently two billion air conditioners worldwide, with some 135 million new units being added each year. The International Energy Agency (IEA) predicts that the number of air conditioners will triple by 2050. This increase poses major challenges in terms of both climate and energy. But solutions do exist to limit their use.
Air conditioning: a dual challenge for climate and energy
To pump cold air inside, the same amount of hot air must be emitted to the outside, which contributes to heating the ambient air and further increasing the need to cool living spaces. A truly vicious circle: as the world warms and many buildings become uncomfortable, inhabitants need air conditioning, which makes the world even warmer.
There are currently two billion air conditioners worldwide.
Some telling figures: according to the IEA, air conditioning is responsible for the emission of around one billion metric tons of CO2 per year, out of a total of 37 billion. And in terms of energy, the growth in the use of air conditioners is a source of concern. If India or China were to reach a 50% ownership rate, the annual production of a country the size of Norway would be required to provide the necessary electricity.
Designing passive housing, a real asset in avoiding air conditioning
Passive buildings, with up to 80% lower energy consumption, are an effective alternative to the systematic installation of air-conditioning units. Reinforced thermal insulation, airtightness, balanced ventilation, orientation according to the cardinal points and winds, revegetation of the surrounding areas, installation of double or triple glazing with solar control, fitting of blinds or shutters, etc. All these options naturally reduce the indoor temperature. Thanks to these multiple assets, numerous projects have come to fruition.
Passive buildings can reduce energy consumption by 80%.
Better insulating existing buildings to reduce the need for air conditioning
In an uninsulated building, 20 to 25% of the energy escapes through the walls, 25 to 30% through the roof and 10 to 15% through the windows, so optimizing the energy efficiency of buildings is clearly a priority.
Up to 80% of the energy needed for heating or cooling can be saved by insulating.
Walls can be insulated either from the outside, with insulation installed under the render or an air gap behind cladding or wall panels, or from the inside, using plasterboard wall lining systems. Rigid or semi-rigid insulation can be installed to insulate walls but must be combined with good airtightness, eliminating stray drafts and thermal bridges.
Different solutions are available for insulating the roof, depending on whether it is a flat roof with insulation below a waterproof membrane, unused roof space with floor insulation, or converted attic space with sloped roof insulation. On the glazing side, the range of solutions is now wide enough to cater to different climates and needs. The layered construction of solar control glass lets sunlight in and either radiates or reflects heat away, as necessary.
Working together to tackle the energy and climate challenge more effectively
While a world without air conditioners may be a utopian dream, solutions exist to stem their pernicious effects: of course, manufacturing more energy-efficient air conditioners, but above all adapting our buildings and environments to make them less vulnerable to heat and reduce the need for air conditioning. To meet this energy and climate challenge, all stakeholders need to work together, and the construction sector is at the crossroads of these issues.
To meet this energy and climate challenge, all stakeholders need to work together.”
Read the full article here.
Would you like to find out more about the role of the construction sector in energy issues? Read other articles on webzine Constructing a Sustainable Future:
- Investing in renovation is crucial to tackle future energy crises
- Energy-efficiency best practices
- The energy performance of buildings in the European Union
- Transport, waste and energy: the winning trio for urban decarbonization
- Smart city: pointless technology or cornerstone of the energy transition?
- What’s the purpose of energy renovation?
- Andreas Rudinger : “The challenge: massifying energy renovation”