News

After three years of collaborative investigation, Ronnen Levinson and Jing Ge of LBNL's Heat Island Group co-authored a paper with Chinese researchers titled, "Cool roofs in China: Policy review, building simulations, and proof-of-concept experiments." Their work characterizes the potential for heat island mitigation, energy use, energy cost, and ambient air quality as a result of replacing dark... Read more

From his office in the Berkeley hills, Art Rosenfeld looks out on the heart of California's Bay Area. The 87-year-old scientist keeps a pencil and a small notebook in his breast pocket, ready to jot down a quick note or make a calculation. With these simple tools he has been able to influence state and national energy policy over the years. But for now they stay tucked away as he enjoys the... Read more

Cool roofs—those with reflectance and emissivity that make them good at keeping out the sun’s heat—are recommended widely without much regard for climate or project specifics. They’ve been adopted into multiple energy codes, including ASHRAE 90.1, the International Energy Conservation Code, and California’s Title 24, not to mention LEED. The concept even has its own bill in the U.S.... Read more

EPA's Heat Island Reduction Program invites you to join our webcast on June 26, 2014 ; please see the details below.Keeping Your Cool: How Communities Across the Country are Reducing the Heat Island EffectThe term "heat island" refers to built-up areas that are hotter than nearby rural areas. The heat island effect can negatively affect communities by increasing summertime peak energy demand, air... Read more

BERKELEY — Every year, thousands of students come to Berkeley with vague ambitions to change the world. The annual Big Ideas@Berkeley competition is inspiring some of them to do just that — by launching globally life-changing innovations even before they graduate. Last week, the program honored this year's winning projects with an awards celebration at the Blum Center for Developing... Read more

The Roof Coatings Manufacturers Association (RCMA) has opened early bird registration for the International Roof Coatings Conference (IRCC). The IRCC will take place at the Royal Sonesta Harbor Court Hotel in Baltimore, Maryland on July 14-17, 2014. This conference will highlight the latest technological advancements and emerging issues of relevance to the roof coating, building envelope, green... Read more

In light of recent criticism of a study authored by several Heat Island Group researchers by the EPDM Roofing Association, the Heat Island Group's Benjamin Mandel (a coauthor of the study) has submitted a response to Today's Facility Manager. See below for a link to the TFM column and for other relevant articles.... Read more

Looking strictly at the economic costs and benefits of three different roof types—black, white and "green" (or vegetated)—Lawrence Berkeley National Laboratory (Berkeley Lab) researchers have found in a new study that white roofs are the most cost-effective over a 50-year time span. While the high installation cost of green roofs sets them back in economic terms, their environmental and... Read more

Two new papers to be published in early 2014 showcase recent Heat Island Group research efforts to improve the measurement and prediction of roofing albedo. A 13-author study titled "Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials" will be published in Solar Energy Materials and Solar Cells.... Read more

What's the coolest place in Los Angeles? It may be right over your head. Starting in 2014, thanks to an update of the Municipal Building Code, all new or refurbished buildings will be equipped with "cool roofs." A cool roof is built of reflective rather than absorptive material. Compared to traditional roofs, cool roofs can be as much as 50 degrees cooler on the roof surface, and can lower... Read more

OverviewThe building envelope – also known as the building shell, fabric or enclosure – is the boundary between the conditioned interior of a building and the outdoors. The energy performance of building envelope components, including external walls, floors, roofs, ceilings, windows and doors, is critical in determining how much energy is required for heating and cooling. The building... Read more

See below for a link to "Cool Roofs Rising" from Ensia, an online magazine from the Institute on the Environment at the University of Minnesota.... Read more

In October 2014, the Heat Island Group will be hosting the 3rd International Conference on Countermeasures to Urban Heat Islands (IC2UHI). The conference will be held in Venice, Italy from October 13-15, 2014 with the support of our colleagues at Università degli studi di Modena e Reggio Emilia. We would like to invite you to contribute and participate! The Conference will be devoted to the... Read more

PORTLAND – On hot summer days, 74-year-old HelenRuth Stephens doesn't dare leave her apartment. Not to get the mail or take out the trash."You don't do it because you'll be breathless by the time you get back," she says.She suffers from asthma and chronic obstructive pulmonary disease. Both affect her lungs. Hot weather drains her energy, she says, and makes it hard for her to breathe.Stephens... Read more

The Heat Island Group's Ben Mandel spoke with Australian radio show Beyond Zero, hosted by Matt Grantham and co-hosted by Chris Jensen (University of Melbourne), about the benefits of cool pavements and LBNL's work to promote cool schoolyards.... Read more

In sweltering September 2011, Fresno could have used more trees. Temperatures climbed, winds died and lung-searing ozone spiked the season's highest readings on three days.Worse yet, all three peaks broke the one-hour federal ozone standard between 3 p.m. and 4 p.m. on weekdays when children were outside after school.An extensive canopy of trees over streets, parking lots and driveways might have... Read more

It is now common to hear about record high temperatures across U.S. cities. Cities are especially susceptible to extreme heat owing to a phenomenon known as the "urban heat island effect." As this effect attracts increased attention and research, new ways are emerging to help cool sweltering cities, which will also save energy and reduce greenhouse gas emissions. One way to counteract the urban... Read more

The Green Parking Council held a webinar on cool pavements as a sustainability measure for parking lots. The webinar featured a presentation on cool pavements by Heat Island Group researchers Haley Gilbert and Ben Mandel. View the recorded webinar below:For more information on the Green Parking Council, see their website. [Note: In 2016, the Green Parking Council was rebranded and launched as... Read more

On Friday, June 21, Heat Island Group researchers George Ban-Weiss and Ben Mandel appeared on the Weather Channel to discuss Berkeley Lab's efforts to demonstrate the heat island mitigation and air quality benefits of cool pavements. Related Video: https://www.youtube.com/embed/U-7q55gDxqQ... Read more

The 34th AIVC Conference, titled "Energy conservation technologies for mitigation and adaptation in the built environment: the role of ventilation strategies and smart materials," will take place 25-26 September 2013 in Athens, Greece. This Joint Conference will focus on ventilative cooling, and is co-sponsored by TightVent, the European Cool Roof Council, and Venticool. The Joint Conference aims... Read more

As a part of Berkeley Lab's ongoing Science Video Glossary, scientists from the Heat Island Group discuss the team's research.Watch Project Scientist George Ban-Weiss explain the causes and effects of the urban heat island effect, as well as Berkeley Lab's efforts to mitigate it and keep cities cooler:Watch other videos featuring Berkeley Lab researchers in the Berkeley Lab Science Video... Read more

(Reuters) - Converting the world's roofs from dark colours to reflective white would cancel the warming effect of 1 billion tonnes of carbon dioxide each year for the lifetime of the roof, according to former California Energy Commissioner Arthur Rosenfeld.The reduction in warming would be equivalent to taking half the world's cars off the road for 20 years, Rosenfeld wrote in a recent commentary... Read more

OK, team, you know this concept. Cities are full of dark surfaces that absorb and capture energy from sunlight, creating islands of hot, hot heat. We all get sweaty, we turn up the A/C, that makes the city hotter, everyone suffers. This is why it's a good idea to paint roofs white. And also why it's a good idea to paint roads pastel green.Out in California, Lawrence Berkeley Lab has a little... Read more

Mayor of Los Angeles Antonio Villaraigosa has directed the Department of Building and Safety to incorporate cool roof requirements in its building code. Mayor Villaraigosa is also asking the Department of Water and Power (LADWP) to create incentives that make it financially attractive for homeowners to install cool roofs.Cool roofs are already mandated in California's Building Energy Efficiency... Read more

On Saturday, March 16, the Heat Island Group added two new cool pavement coatings to the Bevatron Lot at Berkeley Lab. The new additions feature Western Colloid Armor Top asphalt-based coatings in two colors - Stealth Gray (near in image at right) and California Tan (far). The coatings are tinted light colors using titanium dioxide and recycled materials to produce a surface with an initial solar... Read more