Passive cooling, why all buildings should be designed this way.
We can increase thermal comfort and lessen the demand for energy-intensive cooling devices like air conditioners by increasing the use of passive cooling solutions in the architecture of our buildings and towns.
More than 7% of the world’s greenhouse gas (GHG) emissions are produced by cooling systems now, and without clean cooling solutions and a complete switch to renewable energy, these emissions may double by 2050. We need this trajectory to be exactly the opposite as we work to keep the increase in global temperature to 1.5°C (2.7°F). We urgently need to change how we cool ourselves, our food, and our medicines in order to prevent this outcome and to make sure that everyone has access to the cooling they require in this warming world. Yet how?
First, we should lessen the demand for mechanical cooling (like air conditioning) or, in some climate zones, completely prevent its use. This can be done by making our cities—which are warming up twice as fast as the rest of the world—and our structures—whether they be single-family homes, apartment buildings, informal settlements, schools, offices, or factories—naturally cooler.
Where mechanical cooling is still required, we must improve our technologies’ energy efficiency, grid compatibility, and environmental friendliness to reduce their climate impact.
To guarantee that no one is left behind, both of these initiatives must also take place at the same time as initiatives to expand low-income and at-risk populations’ access to effective, environmentally friendly cooling solutions.
Keeping cool, naturally
We can simultaneously lessen heat stress and the requirement for mechanical cooling by scaling up the usage of passive cooling technologies, which will minimise energy use, GHG emissions, and costs.
The Economist Intelligence Unit estimates that decreasing the requirement for air conditioning may save 5.6Gt CO2e1 and US$2.6 trillion in infrastructure investments.
The process of keeping a space cold without using energy is known as passive cooling. It involves employing non-mechanical technology, design components, and/or solutions from nature.
With a variety of strategies, such as energy-efficient building envelopes (insulated walls, for example), reflective surfaces (cool roofs, walls, and pavements), shading (trees, building overhangs, etc.), and blue and green infrastructure (e.g., water features, trees, etc.), we can passively cool our buildings and cities.
At the city scale, the widespread use of cool pavements and roofs can lower summer temperatures by 3.6-5.4°F (2-3°C), and vegetation and tree canopies can lower summer peak temperatures by 1.8-9°F (1-5°C).
In hot regions, insulating walls, roofs, and windows at the building level can save cooling energy requirements by 10% to 40%, and a reflecting roof can cut cooling requirements in a building by up to 70%. In fact, it is conceivable to reduce the requirement for mechanical cooling by 50–80% if buildings were made to naturally make occupants feel comfortable.
Despite their efficacy, scaling up these solutions through building regulations, land use policy, capacity-building, workforce development, and awareness-raising initiatives continues to be a challenge.
Maximising passive cooling in the built environment
At Natural Cool Air our aim is to maximize the efforts and adoption of passive cooling solutions in the built environment. In doing so, we hope to see businesses and cities utilising heat-informed urban planning and design that integrate passive cooling solutions as part of a comprehensive urban cooling solution set and new buildings use better building envelopes and passive cooling approaches.
‘Heat-informed’ urban planning
The use of passive cooling techniques alongside mechanical cooling interventions, such as the use of energy-efficient cooling appliances, might be prioritised by urban planners and designers.
A UNEP-GGGI initiative in Vietnam is one example of this effort; it aids a few pilot cities in creating Urban Cooling Action Programs (UCAPs), which incorporate activities for reducing severe heat into a variety of government plans and policies. The pilots will put the Sustainable Cooling Handbook for Cities’ best practises suggestions into action on the ground.
Strengthening supply-side capacity
To increase the use of passive cooling systems, we must also make sure that there is the labour and material capacity to do so.
For instance, Cool Roofs Indonesia, the winner of the Million Cool Roofs Challenge, is working to increase local production of cool roof coatings with the goal of cutting the cost of producing cool roof materials by around 20% and making them even more affordable. In order to guarantee product quality and performance, they also intend to establish Indonesia’s first testing laboratory for solar reflective materials.
New Building regulations
The International Energy Agency (IEA) estimates that between now and 2050, the world’s building stock will have doubled. It is crucial that these new structures be constructed with thermal comfort and energy efficiency in mind to prevent us from locking in high levels of energy use for decades to come. It is also considerably simpler and less expensive to increase building efficiency before or during construction than it is to make retrofits afterwards.
Sadly, just 80 nations have building rules and regulations in place that outline the minimal energy performance requirements for residential and commercial structures.
Passive cooling for a cooler future for all
We cannot solely rely on air conditioners to help us endure the rising global temperatures, even though they are a useful part of our toolbox. There will be a huge increase in GHG emissions due to the expansion in energy demand from the billions of new cooling appliances, which will increase global warming and the need for cooling. Furthermore, individuals who cannot afford to purchase and maintain air conditioners will be left out in the cold, subject to the high temperatures that are becoming all too commonplace.
The demand for mechanical cooling can be decreased while thermal comfort can be increased. This would result in a decrease in the sector’s GHG emissions and cheaper energy costs for consumers.
Along with improving local air quality through lower emissions, it will also benefit those who live and work in urban heat island zones by enhancing their health, wellbeing, and resilience.
Of course, this effort won’t be enough to address the cooling issue. It must take place at the same time as initiatives to significantly advance cooling technologies and widen access to communities at risk.