UNIVERSITY PARK, Pa. — Ever since humans inhabited buildings, people have worked on improving them. Penn State researchers are no different. A large-scale interdisciplinary effort led by Penn State, called the Global Building Network, is underway to create high-performance buildings, which are buildings capable of achieving net-zero carbon-based energy usage while increasing occupant performance and reducing health risks. These buildings are better for the occupants, as well as the environment and the economy.
One way high-performance buildings can improve the world is through energy efficiency.
According to Tom Richard, director of the Institutes of Energy and the Environment (IEE) and professor of agricultural and biological engineering, buildings are an area where energy efficiency can be vastly improved. He said that with the existing technology and economics, it is possible to reduce the primary energy consumption in buildings by at least 80%.
“The building sector is one of the biggest energy efficiency opportunities to get even better,” said Richard.
“We are going to have 2 billion to 2.5 billion people urbanize in the next 30 years,” said Jim Freihaut, IEE faculty member and professor of architectural engineering. “We need to be more precise about how we're using energy in buildings, so we use less of it.”
According to Freihaut and Greg Pavlak, assistant professor of architectural engineering and an IEE faculty member, the answer is to use sensors and information technology to manage a building’s energy use. Computers can be programmed to utilize a great deal of data, including building schematics, weather forecasts and utility costs, so they can understand all of the dynamics of the building operations and can manage the building’s equipment proactively and as efficiently as possible.
“We're going to have to put a lot more sensors and information technology capability in buildings,” Freihaut said. “Your average car has 100 sensors right now. It's going to have 200 in five to 10 years. The average building has far less sensing, data transfer and real-time data analysis.”
A building’s envelope, or outer shell, can be challenging to get correct, according to Freihaut. He said the key to creating the envelope properly is to understand and design for how the weather will affect that building’s performance, that is, energy use to maintain a quality indoor environment. Making a building envelope without air leaks and minimum thermal conduction is essential to reducing energy use in building operation.
“There's a lot of uncertainty in envelope design,” Freihaut said. “And that uncertainty leads to people specifying cooling and heating systems that are way oversized, generally, just to be safe, and so no one's ever uncomfortable. That leads to that equipment basically operating very inefficiently at part-load conditions.”
Where there is even more potential for energy savings is in communities of buildings, such as a university campus or a business park. Freihaut sees buildings communicating with each other as the future of energy efficiency.
“This exchange of knowledge on how each building operates, and how and when each building needs energy, could minimize the collective amount of energy needed to maximize the amount of indoor environment quality of a community of buildings,” Freihaut said. “That would further reduce the amount of energy supply you need to operate those buildings and could lead to communities of buildings that locally generate and utilize the electric and thermal energy they need, avoiding considerable transmission and distribution loss in the macrogrid.”
Pavlak noted that some of his recent research has shown how smart control of commercial building heating, ventilating and air conditioning systems can help absorb the variability of electricity generated by solar panels (photovoltaics or PV).
“This creates benefits for the grid and other buildings because it means we can install and use more PV on the grid,” said Pavlak. “There could be a trade-off between these more communal grid-level objectives that help the grid operate more efficiently and these building-level objectives, such as minimizing the owner's utility bill.”
Better understanding of these opportunities and trade-offs is currently an ongoing area of research, according to Pavlak.
“Buildings are critical to the health, productivity and safety of societies. In less than 70 years, buildings that once relied on the climate and the active engagement of people to provide thermal comfort and light, now rely primarily on isolated, often automated, building systems with unintended consequences.”
— Corey Griffin, associate dean for research, Penn State Altoona
In addition to being energy efficient, high-performance buildings also are intended to be healthy environments for occupants.
Esther Obonyo, associate professor of engineering, has been working on high-performance buildings in the areas of energy efficiency, resilience and health. In one project, she used air quality sensors as one facet of a project aimed at revitalizing buildings in New Kensington.
“In the last two years, I've started also working in the space of healthy buildings,” Obonyo said. “My students and I are experimenting with some low-cost sensors to provide the health outcomes that we're going after.”
She noted that if a building is not adequately ventilated it can lead to migraines and other health issues.
Obonyo also has been researching ways to make buildings resilient. She has concentrated on how the use and selection of materials can help promote passive ventilation, a method that uses natural forces, such as wind and thermal dynamics, to circulate air in and out of a building. Passive ventilation can lead to improved energy efficiency.
“A lot of the work that I've done in that area has focused on the use of other masonry in different combinations with cement, with fiber reinforcement,” Obonyo said. “So looking at it from a structural adequacy perspective but also bearing in mind what we really want to do is also contribute to passive heating and passive cooling.”
She researched ways to optimize different combinations of bricks that provide the durability and resiliency of fire bricks while at the same time provide passive capabilities.
“A high-performance building needs to perform better than, or at least the same as, the old buildings that have been in existence for 200 years-plus,” said Obonyo. “Extreme weather events have become more frequent and unpredictable, and when we use these materials in combination with other building systems, we're also very interested in making sure that they can resist lateral loads [e.g., wind or an earthquake] especially.”
According to Corey Griffin, associate dean for research at Penn State Altoona, buildings are responsible for 40% of all carbon dioxide emissions, contributing to global climate change and the doubling of weather-related natural disasters over the last 30 years. He said the incremental improvements and making buildings “less bad” will not suffice in the face of global climate change during a time of increasing urbanization.
“Buildings are critical to the health, productivity and safety of societies,” Griffin said. “In less than 70 years, buildings that once relied on the climate and the active engagement of people to provide thermal comfort and light, now rely primarily on isolated, often automated, building systems with unintended consequences.”
Griffin said to improve buildings, because they are so complex today, they must be thought of as whole systems instead of separate parts.
“This need will require us to focus on whole-systems thinking and integration across disciplines as optimizing individual components or even a single system can only make a building ‘less bad,’” Griffin said.
Shirley Clark, professor of environmental engineering at Penn State Harrisburg, works on stormwater management as it relates to high-performance buildings.
“Initially, I was working on the pollutant concerns from our choices of roofing materials and noting that many of our common roofing materials were leaching pollutants at levels that could be detrimental to plants,” Clark said. “One potential solution to this was green roofing.”
According to Clark, green roofing has been well advertised as a way, through the addition of a vegetative layer to the roofs of buildings, to reduce the air conditioning load for buildings and by protecting the roof surface from the sun.
“Several studies have documented the reduced air conditioning load and energy savings associated with green roofs,” Clark said. “With stormwater, plants also reduce the amount of runoff from the roof, which reduces the water load to the storm sewer system.”
It is not just large commercial buildings that can benefit from becoming high-performance. Residential buildings are also excellent candidates.
Lisa Iulo, associate professor of architecture and director of the Hamer Center for Community Design, said there are approximately 24 residential buildings for every commercial building in the U.S. She has been working in the high-performance residential building space for years, including Pennsylvania’s first affordable “green” residential development, Petersburg Commons in Duncannon, completed in 2008.
“We have been continuing to work with State College borough, State College Community Land Trust, and other local affordable housing providers on a program called Energy+,” Iulo said. “This involves adapting building science, envelope improvements and other methods of high-performance design to the existing residential buildings in order to improve the energy efficiency, durability and healthfulness of existing dwelling units and thus reduce the operating expenses for homeowners.”
In response to the 2014-15 Department of Energy’s Race to Zero competition, Penn State and its partners completed two zero-energy homes in State College. They were designed through a collaborative, community-design approach and are intended as a demonstration for the region. The project was recently awarded a “U.S. Green Building Council Central PA Leader Award 2018, Innovation Project – Residential.”