Archinect - News

'Cool roofs' found to be most effective in combatting urban heat, Bartlett study says

2024-07-31T20:17:00-04:00

Researchers at the University College London have put forth a new argument in favor of a simple solution to combating the issue of extreme heat in cities without air conditioning. The so-called “cool roof” method they found had the best mitigation performance metrics over others surveyed (green roofs, A/C, solar panels, and street-level plant integrations), reducing heat by between 1.3 and 2 degrees Celsius when applied in the right conditions.

Lead author Dr. Oscar Brousse of the UCL Bartlett School Environment, Energy & Resources said: “We comprehensively tested multiple methods that cities like London could use to adapt to and mitigate warming temperatures, and found that cool roofs were the best way to keep temperatures down during extremely hot summer days. Other methods had various important side benefits, but none were able to reduce outdoor urban heat to nearly the same level.”

The findings will of course have bearings on public health and urban design efforts outside of Lo...

Researchers create ultra-white paint that could cool buildings

2021-04-16T17:54:00-04:00

Scientists in the US have developed a paint significantly "whiter than the whitest paint currently available". Tests carried out by researchers at Purdue University on their "ultra-white" paint showed it reflected more than 98% of sunlight. That suggests, the scientists say, that it could help save energy and fight climate change.

The paint's whiteness opens up a range of cooling features that, applied at an industrial scale, could limit the built environment's contributing effect to global warming and its dependency on traditional air conditioning.

"If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses," predicts Xiulin Ruan, the Purdue professor of mechanical engineering, who led the research.

An infrared camera shows how a sample of the whitest white paint (the dark purple square in the middle) actually cools the board below ambient temperature. Credit: Purdue University/Joseph Peoples.

"Using high-accuracy temperature reading equipment called thermocouples, the researchers demonstrated outdoors that the paint can keep surfaces 19 degrees Fahrenheit cooler than their ambient surroundings at night," claims the study. "It can also cool surfaces 8 d...

Powerhouse Company's "Paper Roof" reception center has been completed in Tianjin, China

2021-01-15T12:26:00-05:00

Powerhouse Company's "Paper Roof," the new design for a reception center in Tianjin, China has been completed. The form is a transparent glass block topped by a light sweeping roof inspired by traditional Chinese architecture.

Photo by Weiqi Jin

The roof raises 18.5 meters at its highest point with a surface measurement of 30 meters x 50 meters. The canopy is made from powder-coated steel, colored a tone intended to mimic the sky.

Photo by Weiqi Jin

Inside the pavilion, a large atrium offers panoramic views of the surrounding lake and gardens. The second floor includes offices and a viewing balcony in addition to seating areas for small and large gatherings.

Photo by Weiqi Jin

'Cool roofs' substantially reduce temperatures during a heat wave, according to new study

2015-12-22T19:39:00-05:00

It is well established that white roofs can mitigate the urban heat island effect, reflecting the sun's energy back into space and reducing a city's temperature. In a new study of Guangzhou, China, researchers found that during a heat wave, the effect is significantly more pronounced. Reflective roofs, also called cool roofs, save energy by keeping buildings cooler, thus reducing the need for air conditioning.

According to a new study by Berkeley lab researchers Dev Millstein, Ronnen Levinson, and Pablo Rosado, alongside Meichun Cao and Zhaohui Lin of the Institute of Atmospheric Physic in Beijing, so-called "cool roofs," or roofs painted white, substantially reduce the urban heat island effect during a heat wave.

Prior research had shown that cool roofs could mitigate the urban heat island effect, but the new study shows just how drastically this can make a difference during a heat wave. Heat waves affect both public health and energy resources, requiring massive amounts of air conditioning and other cooling systems that can overtax the electric grid.

"The hotter it is, the more cooling you get with cool roofs--and it is a significant difference, compared to the margin of error," Millstein told ScienceDaily. "We found that the stagnant conditions of a heat wave, where the air is just sitting over the city, was one of the main factors."

The research was conducted in Guangzhou, a large city ...