How to make homes cooler without cranking up the air conditioning
Air conditioners often become the default solution when temperatures rise but they’re not the only answer
Jesus Lizana, Marie-Curie research fellow in the Department of Engineering Science, Nicole Miranda, senior researcher and college lecturer in Engineering, and Radhika Khosla associate professor, Smith School of Enterprise and Environment at the University of Oxford explain the easy ways to keep cool as the mercury rises.
Temperatures around the world are soaring. Both California’s Death Valley and China’s Xinjiang region have seen temperatures climb above the 50℃ mark. A blistering heatwave is also sweeping across the Mediterranean, causing temperatures in parts of Italy, Spain, France and Greece to exceed 40℃.
In the future, the impact of scorching temperatures will extend beyond traditionally warm regions. In fact, our new research indicates that, if global temperature rise increases from 1.5℃ to 2℃, countries at northern latitudes like the UK, Norway, Finland and Switzerland will face the greatest relative increase in uncomfortably hot days.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
During uncomfortably hot weather, people seek ways to cool down their homes. Air conditioners often become the default solution when temperatures rise as they provide fast and effective relief from scorching heat.
But air conditioners consume a lot of energy. Many also use refrigerants called fluorinated gases that have high global warming potential when they leak.
Unrestrained usage of air conditioners in the future will result in increased emissions and further global warming. So it’s important to know the recommended steps to keep your home cool in the face of rising temperatures, without causing the climate more harm.
Block the sun
Buildings can be protected from too much heat by creating a barrier between them and the sun’s rays. There are different ways to achieve this, ranging from reflective and ventilated roofs to external window shutters and awnings. Research one of us worked on in Spain found that using external window shutters can reduce cooling needs (the thermal energy required to keep people comfortable) by up to 14%.
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Even something as simple as painting your roof a light colour can reduce indoor temperatures. Research in very hot cities in Pakistan found that, by reflecting the sun’s energy, this approach can reduce cooling needs by more than 7%.
Another effective technique is to make use of the shade provided by tree canopies. Research in Melbourne, Australia, has shown that trees covering buildings in shade can lower the surface temperature of walls by up to 9℃.
Use natural ventilation
One effective way to cool down a poorly ventilated building, is to open windows when the outside temperature drops. This lets warm air escape and invites cooler air in.
But additional features, such as ventilation chimneys and roof vents, can be incorporated into building design to further assist airflow. These features are often found in hot and arid climates, particularly in the Middle East. Historically, buildings in this region made use of tall, chimney-like structures called wind catchers that capture cool prevailing winds and redirect them into homes. Ventilating a building with cool air at night can also keep it cool for longer during the day.
Buildings can also be “cross ventilated”, where a fresh breeze enters through an opening and exits through another on the opposite side. If necessary, this can be promoted by incorporating inner courtyards – a design that has been used for centuries in warmer climates to keep buildings cool.
Our previous research found that inner courtyards can reduce the total amount of time in which we need to take measures to cool down (known as indoor discomfort hours) by 26%.
Cooling beyond temperature control
Our perception of coolness is not solely determined by temperature. Factors like humidity and air speed also play a role in how comfortable we feel.
That’s where fans come in handy, whether they’re on the ceiling or standing on their own. By combining fans with air conditioning, it’s possible to raise the thermostat setting from 24℃ to 27℃ and still feel cool. This simple adjustment can reduce household energy consumption for cooling by more than 20%.
Centralised air conditioning systems also often end up cooling us down more than necessary or even waste energy by cooling empty rooms. But we can tackle this by combining more relaxed cooling settings, like raising the thermostat, with personal cooling devices such as desk fans, cooled seats or wearable thermoelectric coolers. These devices allow people to have more control of their immediate cooling needs without having to cool down an entire space.
When air conditioning still remains necessary, choose units with a high efficiency rating using refrigerants with low global-warming potential. To figure out how efficient they are, there’s an indicator called the energy efficiency ratio (ERR) – you’ll want to pick a unit with an ERR that’s close to or above four.
When designing or adapting buildings, it’s essential to consider the overall heating and cooling demands. For example, maximising ventilation can prevent overheating during summer, but minimising ventilation can help reduce the need for heating during winter.
The key is to find solutions that work well together and can be adapted easily so that the cost of installing energy-intensive air-conditioning systems can be avoided or reduced. This approach will allow people to stay comfortable during hotter temperatures, without compromising the climate further for future generations.
Jesus Lizana, Marie-Curie Research Fellow, Department of Engineering Science, University of Oxford; Nicole Miranda, Senior Researcher and College Lecturer in Engineering, University of Oxford, and Radhika Khosla, Associate Professor, Smith School of Enterprise and Environment, University of Oxford
This article is republished from The Conversation under a Creative Commons license. Read the original article.
-
The clown car cabinet
Opinion Even 'Little Marco' towers above his fellow nominees
By Mark Gimein Published
-
Ed Park's 6 favorite works about self reflection and human connection
Feature The Pulitzer Prize finalist recommends works by Jason Rekulak, Gillian Linden, and more
By The Week US Published
-
6 fantastic homes in Columbus, Ohio
Feature Featuring a 1915 redbrick Victorian in German Village and a modern farmhouse in Woodland Park
By The Week Staff Published
-
Cuba roiled by island-wide blackouts, Hurricane Oscar
Speed Read The country's power grid collapsed for the fourth time in just two days
By Peter Weber, The Week US Published
-
What does marine life do during a hurricane?
The Explainer The underwater ecosystem also faces deadly consequences
By Devika Rao, The Week US Published
-
Floridians flee oncoming Hurricane Milton
Speed Read The hurricane is expected to cause widespread damage in the state
By Peter Weber, The Week US Published
-
Hurricane Helene death toll rises, North Carolina reels
Speed Read At least 95 are dead following catastrophic flooding
By Peter Weber, The Week US Published
-
Hurricane Helene storms Florida's Big Bend
Speed Read Helene is among the biggest hurricanes to ever strike the Gulf Coast
By Peter Weber, The Week US Published
-
Dozens dead in Vietnam after 'worst typhoon' in 30 years
At least 58 people are dead and hundreds are missing after Typhoon Yagi made landfall
By Rafi Schwartz, The Week US Published
-
The Earth just saw its hottest day on record
Speed Read July 21, 2024 was the hottest day in recorded global history
By Rafi Schwartz, The Week US Published
-
Prisons are simply not prepared for extreme heat
Under the radar Inmates are at severe risk of heat-related illness
By Devika Rao, The Week US Published