Tag energy efficiency

When exposed to direct sunlight, asphalt surfaces are capable of reaching temperatures up to 172 degrees Fahrenheit. Roads and rooftops everywhere bake during the hottest time of the year, creating a “heat island effect.”

According to the Environmental Protection Agency, heat islands are “built up areas that are hotter than nearby rural areas. The annual mean air temperature of a city with 1 million people or more can be 1.8–5.4°F (1–3°C) warmer than its surroundings. In the evening, the difference can be as high as 22°F (12°C). Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and mortality, and water quality.”

Luckily, a new technology might provide a solution. Researchers at the University of Technology in Sydney have developed a new material that can keep roofs cooler than the air above them — even in direct sunlight — thus reducing the effect of heat islands.

“We demonstrate for the first time how to make a roof colder than the air temperature around it, even under the most intense summer conditions,” said study co-author and Emeritus Professor Geoff Smith in a press release.

The super cool material is made of specialized plastics stacked on top of a layer of silver, and reflects 97% of the sunlight that hits it. In other words, it reflects sunlight so well that it doesn’t even warm up.

Compared to the energy efficient roofing materials currently available, the new material stays a whopping 50 degrees cooler.

“Cool roofing reduces the severity of the urban heat island problem in towns and cities and helps eliminate peak power demand problems from the operation of many air conditioners,” said Smith.

Although the material is not yet available to the market, it hopefully will be soon. With a warming planet and massive populations already suffering, the new material may be the key to staying cool in the face of a global inferno.

“Our findings show that cities continue to be laboratories of innovation when it comes to energy efficiency, with many pushing the envelope for more energy savings in the last few years,” said lead author David Ribeiro in a May 20 news release. “Cities are also improving their approaches when it comes to tracking and communicating their efforts to save energy. By capturing these efforts in the [City Energy Efficiency] Scorecard we hope local leaders from cities of all sizes can learn best practices from each other and deliver the benefits of energy efficiency to their communities, such as a stronger economy and a cleaner environment.”

Energy efficiency refers to doing the same amount of work with less energy — essentially, improving energy usage without sacrificing any function or convenience. With efficiency in mind, Boston has implemented a number of city-wide energy policies as well as focused on energy and water usage in large and medium-sized buildings.

The city has also made efforts to engage residents on a personal level and get them invested in conservation and efficiency efforts. Many of the choices made in the home, particularly when it comes to appliances, can have a large collective effect on overall efficiency; heating and cooling equipment, for example, tends to become less efficient over time, but few people know that HVAC equipment often physically lasts longer than it is economically viable.

Boston was followed in the rankings by New York City, Washington, San Francisco and Seattle. The lowest-ranking city was Oklahoma City, with Birmingham, Raleigh, Detroit and New Orleans rounding out the bottom five.

Several cities near the top of the list have shown marked improvement since last year’s assessment from the ACEEE. Those include Washington (2), Los Angeles (12), Chicago (6), Minneapolis (7) and Seattle (5).

As the report points out, however, there’s still quite a bit of room for improvement even in the most efficient cities. Boston was the only city to earn above 80 points (out of 100), and only 13 cities total scored above a 50%.

The study’s author, Julia Day, was a graduate student in interior design when she first encountered issues with building sustainability. Her interest in the subject began when she walked into an office designed for energy-saving daylighting techniques only to see the blinds closed and numerous lights turned on.

Worse, Day discovered that the controls for the blinds and lights were hidden high up on walls or down underneath desks, and not many of the workers knew how to properly use these devices.

From there, Day embarked on her study of effective training in using the features in high-performance buildings, which consist of over one-third of new commercial building constructions in the U.S.

Perhaps most encouraging is that Day discovered that those who had proper training in their building’s energy-saving features reported being the most satisfied with their work environments.

Day, who is now an assistant professor at Kansas State University, worked with WSU School of Design and Construction professor David Gunderson to examine more than 50 high-performance buildings across the United States. Day gathered data on the buildings’ architectural and engineering plans, and interviewed and surveyed the occupants of those buildings.

In many cases, Day found that workers in office buildings received an email or a quick overview of energy features in their buildings during a meeting, but they didn’t actually understand the best practices for those features.

Windows, for example, are often upgraded to provide daylight, ventilation and heat in the winter, but they can also account for at least 10% to 25% of a heating bill if they are outdated. As a result, many commercial and residential property owners upgrade their single pane windows to energy efficient models, especially as utility costs increase all around the country.

Day looked at energy efficiency for the windows of Leadership in Energy and Environmental Design-certified buildings in her study. These spaces, certified as high-performance in energy efficiency by the U.S. Environmental Protection Agency’s Energy Star program and/or the U.S. Green Building Council’s LEED initiative, have increased from 5.6% in 2005 to 39.3% by the end of 2013, according to CBRE Research.

One building certified LEED gold by the Green Building Certification Institute had lights throughout to indicate the best times of day to open and close windows for natural ventilation. But out of the 15 people Day interviewed, all thought that the lights were part of the fire alarm system.

“There’s a gap,” she said of green building occupants’ knowledge, “and people do not really understand these buildings.”

Day found that the most successful of these green buildings had workers who were involved in the act of conservation by receiving adequate training on their buildings’ features.

After concluding her study, Day said she has plans to develop an energy lab to develop occupant training programs for these high-performance buildings.

“With stricter energy codes, the expectations are that buildings will be more energy efficient and sustainable,” Day commented. “But we have to get out of the mindset where we are not actively engaged in our environments.”