Building Systems Engineering

Does turning the air conditioning off when you're not home actually save energy?

Anonymous — Mon, 22 Aug 2022 17:16:04 +0000

Does turning the air conditioning off when you're not home actually save energy? Anonymous (not verified) Mon, 08/22/2022 - 11:16

Hot summer days can mean high electricity bills. People want to stay comfortable without wasting energy and money. Maybe your household has fought over the best strategy for cooling your space.

Which is more efficient: running the air conditioning all summer long without break, or turning it off during the day when you’re not there to enjoy it?

A team from the Department of Civil, Environmental and Architectural Engineering set out to find the answer.

Check out the results of work by Assistant Professor Kyri Baker, Assistant Teaching Professor Jennifer Scheib, and architectural engineering PhD student Aisling Pigott in a new column in The Conversation.

Read the full column...

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Transformative Carbon-Storing Materials report co-authored by Wil Srubar

Anonymous — Wed, 10 Nov 2021 19:27:57 +0000

Transformative Carbon-Storing Materials report co-authored by Wil Srubar Anonymous (not verified) Wed, 11/10/2021 - 12:27

Jeff Zehnder

Read the report at the Carbon Leadership Forum.

The Carbon Leadership Forum has published a new report on the potential for meaningful climate impact through materials that serve as carbon sinks. Co-authored by Wil Srubar, an associate professor in the Department of Civil, Environmental and Architectural Engineering at the 91��Ƭ��AV, the report, partially funded by Microsoft, highlights ways building construction can use new materials to reduce our carbon footprint and even become "carbon positive."

Below, Srubar shares his insights on the importance of the report and the research on which it is based.

How does this report add to the conversation about climate solutions?

Today, more than 11% of global CO2 emissions are due to the manufacturing building materials, like cement and steel. This report specifically outlines how buildings can become part of the climate solution by using materials that actually store more CO2 than is emitted in its manufacture.

How do new building materials that can function as carbon sinks compare to older materials like traditional concrete?

We’ve been building with materials that store carbon, like wood, for millennia. In addition to wood products, there are a myriad of other materials that can be grown using CO2. New, high-performance building materials from hemp, straw, even algae, are grown using CO2 as a feedstock. Researchers have transformed these materials into durable, drop-in replacements for materials that are already used in buildings.

Wil Srubar

When will people start seeing these new materials used more broadly?

This report is really transformative in that it identifies materials and solutions that are commercially available today. The report is a handbook of sorts for architects and engineers to know what alternatives are available for designing zero-carbon or carbon-storing buildings.

How did Microsoft get involved in this? As a software company, it doesn’t seem like an area where they would have interest.

Microsoft has made very bold commitments to carbon neutrality. Microsoft builds a lot of data centers. In fact, they will be building 50-100 new data centers every year for the foreseeable future. If built using traditional materials, these buildings could further harm the climate. Microsoft has committed to using their data centers as a vehicle for healing the climate instead.

What are you most excited about in this report?

Personally, I am most excited about the ways in which algae will help transform buildings into carbon sinks. Algae are more efficient than trees, straw, and hemp at sequestering and storing CO2. This reports highlights a few emerging, high-performance building material technologies based on algae. Many of these are coming out of my lab at CU. If we can lock-up and store that CO2 for decades—even centuries—in long-lasting building products, it will have a tremendous benefit to the climate.

Read the report at the Carbon Leadership Forum

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Major research center for green building technology launches at CU Boulder

Anonymous — Wed, 22 Sep 2021 14:17:10 +0000

Major research center for green building technology launches at CU Boulder Anonymous (not verified) Wed, 09/22/2021 - 08:17

Jeff Zehnder

A major research center for sustainable building technology has been founded at the 91��Ƭ��AV.

The Building Energy Smart Technologies (BEST) Center is a new, five-year multi-university initiative funded by the National Science Foundation to advance sustainable building projects ranging from HVAC manufacturing, to smart glazing for windows, building controls, insulation, as well as solar installations.

“This is a long term commitment to solve industry problems and make buildings adaptive,” said Moncef Krarti, director of the center and a professor in the Department of Civil, Environmental and Architectural Engineering. “Many western countries want to be net zero in carbon emissions by 2050. That’s a significant challenge. To achieve that, we need a new set of innovative and smart technologies. We have to combine energy efficiency, reduce demand, and deploy renewable energy into buildings so they can be a net positive, actually producing energy, not just consuming power.”

The project is focused on business collaboration, directing research into areas needed for the construction industry and building retrofits. The new center will operate under the NSF Industry-University Cooperative Research Centers model. This setup is designed to help startups, large corporate partners and government agencies connect directly with university researchers to solve common research obstacles in a low-risk environment. The aim is to develop new technology faster and build out the U.S. workforce in critical areas.

“This will be a really interactive process between industry and universities with what problems to solve. Each project we take on will have an industry sponsor,” Krarti said.

The NSF grant will provide $1.5 million over five years, matched by industry associates for a total of at least $3.0 million. Ten industry partners are already onboard with the initiative.

CU Boulder is the lead for the center, with the City College of New York as a partner site, offering the opportunity research and test new building technologies in the largest metropolitan area in the United States.

The work in New York will be led by Jorge González, Presidential Professor of Mechanical Engineering at CCNY.

“This is a major milestone and opportunity, as it validates our long-term efforts in research and education on building systems as supporting activity to our city,” González said. “We will be providing engineering and technology solutions to connect the outdoors environment to the indoors of buildings to enable smart and sustainable responses.”

In addition to meeting emissions goals, new smart and adaptable technologies in the built environment will provide responses for increasingly frequent extreme weather events due to the rapidly changing climate. The work will also direct attention on emerging challenges in the building sector due to pandemics and health crises such as those caused by COVID-19.

“It’s hard for industry to fund research, but this center is a vehicle to that collaboration. It’s a big deal,” Krarti said. “We spend 80% of our time in buildings. We need to make sure buildings are sustainable and healthy as well as comfortable.”

In addition to Krarti and Gonzalez, other CU Boulder faculty partners include Kyri Baker, Gregor Henze, Wil Srubar, John Zhai, and Wangda Zuo, all in the CU Boulder Department of Civil, Environmental and Architectural Engineering, as well as Michael McGehee in the Department of Chemical and Biological Engineering.

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Zuo an International Building Performance Simulation Association Fellow

Anonymous — Thu, 26 Aug 2021 21:56:07 +0000

Zuo an International Building Performance Simulation Association Fellow Anonymous (not verified) Thu, 08/26/2021 - 15:56

Associate Professor Wangda Zuo has been elected a fellow of the International Building Performance Simulation Association.

IBPSA is a non-profit international society of building performance simulation researchers, developers and practitioners dedicated to improving the built environment.

Zuo is a leading researcher in building system modeling and indoor environmental modeling. He has spent nearly 20 years in building modeling and simulation with significant contributions in the development of various open source software including Fast Fluid Dynamics model, Modelica Buildings Library, Modelica Smart and Connected Community Library, and Modelica Net Zero Energy Community Library.

He has been serving as IBPSA Treasurer and Affiliate Director representing the United States since 2016. He is the founding Chair of the IBPSA-USA Research Committee (2014-2018) and former Chair of ASHRAE TC 4.10 Indoor Environment Modeling (2019-2021).

Zuo joined the Department of Civil, Environmental and Architectural Engineering at CU Boulder in 2017 and also holds an appointment in the Buildings and Thermal Sciences Center at the National Renewable Energy Laboratory.

His election will be officially recognized at the IBPSA Building Simulation 2021 conference in Bruges, Belgium, being held Sept. 1-3, 2021.

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Cities like Paris may be optimal urban form for reducing greenhouse gas emissions

Anonymous — Tue, 10 Aug 2021 21:20:33 +0000

Cities like Paris may be optimal urban form for reducing greenhouse gas emissions Anonymous (not verified) Tue, 08/10/2021 - 15:20

Researchers at CU Boulder are part of a newly published study that finds that low-rise, high-density environments like those found in Paris are the optimal urban form when looking to reduce greenhouse gas emissions over their whole life cycle.

The work, recently published in npj Urban Sustainability, builds on a growing debate around the design of future urban environments and was done in partnership with Edinburgh Napier University. The built environment is a big contributor to carbon emissions, global energy demand, resource consumption and waste generation. In the U.S., it accounts for 39% of all greenhouse gases emissions, while in the European Union, it accounts for 50% of all extracted materials and 42% of the final energy consumption – making it a rich area for understanding and improvement related to climate change.

Jay Arehart, an author on the paper and instructor in the Department of Civil, Environmental and Architectural Engineering, said the work challenges current conventional understanding that tomorrow’s cities must be densely packed and stretch upwards to address and curb greenhouse gas emissions. The idea being that tall buildings make optimal use of space, reduce operational energy use for heating and cooling and enable more people to be accommodated per square meter of land.

“Both the urban sprawl that we see in the suburbs of the United States and the high-rise that we see in places like New York City are not necessarily optimal,” Arehart said. “We showed that new development should focus on minimizing whole-life carbon of buildings, not just the emissions from their operations or their materials. That density is needed for a growing urban population, but height isn't.”

The team investigated four different urban typologies – from dense-and-tall to sparse-and-low – by simulating 5,000 environments based on real-world data to establish their lifecycle greenhouse gas emissions. This approach considered both premium for land (the extra land needed to build low-rise compared to high-rise) and premium for height (the extra materials to build high-rise compared to low-rise) to make comparisons fair said Francesco Pomponi, the lead author on the paper and professor at Edinburgh Napier University.

"We developed a novel urban density metric to measure things up as accurately as possible," Pomponi said. "Our results show that density is indeed needed for a growing urban population, but height isn't. So it seems the world needs more Parises and fewer Manhattans – as much as I love New York – in the next decades."

Urban Sustainability is the newest addition to the Nature Partner Journals series.

Full paper

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International research partnership aims to reduce residential energy consumption

Anonymous — Thu, 22 Jul 2021 17:26:15 +0000

International research partnership aims to reduce residential energy consumption Anonymous (not verified) Thu, 07/22/2021 - 11:26

Researchers at CU Boulder are working with colleagues in Ireland to help policymakers and other stakeholders reduce residential energy consumption and the related greenhouse gas emissions that come from it. The project ultimetly aims to provide leaders with the data-driven tools needed to make decisions about retrofitting residential energy solutions.

The CU Boulder team is led by Associate Professor Wangda Zuo from the Department of Civil, Environmental and Architectural Engineering.

“Our team will be leading the building energy modeling and machine learning aspect of the project,” Zuo said. “The hope is the information we generate together with the rest of the team will lead to better decisions at the local and national levels as society begins seek and install green solutions for the built environment.”

The work – titled “Intelligent Data Harvesting for Multi-Scale Building Stock Classification and Energy Performance Prediction” – is funded by the National Science Foundation, the Science Foundation Ireland, and the Department for the Economy in Northern Ireland as part of the U.S.-Ireland Research and Development Partnership.

The partnership is a unique initiative involving funding agencies across three jurisdictions: the United States of America, Ireland and Northern Ireland. The overall goal is to increase research and development collaboration amongst researchers and industry across those jurisdictions – generating valuable discoveries and innovations that are transferable to the marketplace or will lead to enhancements in health, disease prevention or health care. Residential buildings account for 14% to 27% of greenhouse gas emissions in the three jurisdictions, making it an important area for collaboration and interdisciplinary research.

Eventually, the team will ask the U.S. Department of Energy's Pacific Northwest National Laboratory to adopt the research results into their national building energy policy analysis for 139 million homes. The Northern Ireland Housing Executive will also utilize this work to help predict decarbonization pathways for their housing stock of nearly 86,000 homes – about 10% of the housing stock in Northern Ireland. And the work will also assist the Sustainable Energy Authority of Ireland with its retrofit plan of 500,000 homes in the Republic of Ireland.

The total funding for the project is about €1 million euros, or about $1.18 million dollars, across the three nations and work will begin in September, running for three years. Partner institutions on the project include University College Dublin and Ulster University.

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CU Boulder Fulbright Scholar bringing energy research to Australia

Anonymous — Thu, 10 Jun 2021 19:52:20 +0000

CU Boulder Fulbright Scholar bringing energy research to Australia Anonymous (not verified) Thu, 06/10/2021 - 13:52

Jeff Zehnder

Gregor Henze is expanding renewable energy research Down Under.

A 91��Ƭ��AV professor in the Department of Civil, Environmental and Architectural Engineering, Henze is a 2021 honoree of the Fulbright Distinguished Chair in Science, Technology and Innovation.

Through the initiative, Henze will spend a semester in Newcastle, Australia at the Commonwealth Scientific and Industrial Research Organisation (CSIRO). Henze anticipates traveling to Australia to begin the fellowship in February 2022. A scholar in renewable energy, energy efficiency and distributed energy solutions, Henze will be sharing his expertise as a CU Boulder professor and as associate director of the Renewable & Sustainable Energy Institute on campus. Henze also holds a joint appointment at the National Renewable Energy Laboratory in Golden.

“Australia is a vast country with similar challenges to us with large energy systems covering large distances,” Henze said. “We and they alike are trying to transition to low-carbon or no-carbon fuels. They’re especially interested in how buildings, mostly commercial buildings, can benefit from data-driven digitalization.”

An area of focus for Henze, data-driven digitalization of the energy sector includes predictive HVAC controls and systems to detect faults in existing buildings as well as adding renewable energy and batteries that can feed power back into the grid.

“There’s an often-quoted estimate that you can walk into any US commercial building and save between 10-30% through better controls and fault detection. Buildings are not run well and are not run efficiently,” Henze said. “But just focusing on that is not enough. We also must focus on the greater system and building-to-grid interaction -- to have 5.5 million commercial buildings that instead of just being merely energy sinks, they also produce, shift, and store electric power. However, such an energy system becomes vastly more complicated.”

Although integrating significant numbers of commercial buildings into the grid in this way increases complexity, Henze said it supports a greener future for power generation.

“Roughly 75% of our electricity is consumed by buildings. I started my career working on the large-scale power generation side: nuclear power and traditional fossil-powered designs. But I felt like it was incremental and that we needed to change the way we use energy, which got me interested in demand and buildings,” Henze said.

The Fulbright honor is a unique callback for Henze to an earlier time in his education – when he was an graduate student selected for the program’s better-known student scholarships, which bring foreign college students to America for study.

“I’m particularly humbled because a long time ago I was privileged to be a Fulbright scholar as a student from Germany coming to the United States. It’s coming around full circle, in a way,” Henze said. “I planned to be here one year in 1990-91. Now 30 years later as a naturalized American, I’m hoping to bring American research excellence to Australia, serving as an ambassador for the United States. It feels like an enormous honor to be chosen.”

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Baker to address long standing grid optimization problems in CAREER award

Anonymous — Tue, 16 Mar 2021 15:53:19 +0000

Baker to address long standing grid optimization problems in CAREER award Anonymous (not verified) Tue, 03/16/2021 - 09:53

Every day – multiple times a day – power grid operators make a complex calculation to solve a supply and demand problem.

They must quickly decide how much energy their systems need to produce to accommodate the demand from their users at that moment. On average, these calculations take about five to 15 minutes as dozens of factors are considered and resolved on how to get power from generators through lines to users. Thousands upon thousands of people rely on these calculations being correct for clean water, heat and many other aspects in their daily lives, making it a complex yet critical balancing act.

Assistant Professor Kyri Baker has been working to optimize those calculations in her research for years, developing algorithms that coordinate assets quickly to keep the lights on. But new demands, more intermittent renewable energy, and more general uncertainty in the system have made things increasingly complicated, she said.

Charging a single electric vehicle can consume more energy than a house consumes in a whole day, for example, Baker said. That kind of demand has implications for our power generation and distribution infrastructure. At the same time, overall power generation is increasingly coming from renewable sources like solar and wind, which may fluctuate many times a day due to small changes in the weather. And the resulting power is being transmitted through systems that can fail at various points, as was seen during deadly winter storms in Texas in February 2021.

All of that means the calculations needed to keep the lights on will need to take more factors into account while also making decisions in seconds, not minutes, in the near future. That is going to be hard to do because these algorithms are complex, Baker said.

“They take a lot of time to solve because there are so many variables and constraints at play. Solving this large optimization problem efficiently is a challenge we have been trying to address since the 1970s,” she said. “The key innovation here is that there are fundamental limits to how fast we can currently solve these large problems.

“Ideally, we want to completely bypass solving an optimization and instead use all of the data that is already collected in the grid to train a predictive model to determine how power plants should operate. This takes seconds instead of minutes and can help us maintain grid stability and efficiency on faster timescales.”

Baker, who is based in the Department of Civil, Environmental and Architectural Engineering, was recently awarded an NSF CAREER Award to pursue that idea. The award provides up to $500,000 over five years to support the research and educational activities of early career faculty members who have the potential to become leaders in their field. Through the new award, Baker will work to speed those solution times through the use of historical data and machine learning – computer algorithms that improve automatically through experience over time.

Baker

Baker said operators have been collecting data for years, and appropriate machine learning models have been around for a while as well. But recent advancements in computing now allow for understanding of highly complex relationships that can be used to train the large-scale models needed to solve this problem. The most challenging piece, she said, will be convincing leaders at utilities this method is something they should adopt.

“We are trying to create these algorithms in a transparent way so operators can have confidence they will work,” she said. “This infrastructure is of one of the most complex and critical systems in our society, and it’s not just a matter of efficiency and cost, but also life and death. So there really is a need to show that this can be done in a safe and secure way where the reason for the decisions being made is clear to everyone involved.”

Baker also has a courtesy appointment within the Department of Electrical, Computer and Energy Engineering and is a Fellow of the Renewable and Sustainable Energy Institute, a joint institute between the National Renewable Energy Laboratory (NREL) and CU Boulder. She completed her undergraduate degree and PhD in electrical and computer engineering from Carnegie Mellon University and served as a postdoctoral researcher at NREL before coming to CU Boulder.

As part of this CAREER award, Baker will also be creating a scholarship competition around machine learning for use with the power grid. She said she was particularly looking to engage with and reach LGBTQ students through that initiative as a member of that community herself.

“I think it is often a hidden trait about yourself and something I know I struggled with in my career – feeling like I couldn’t be myself going to conferences or applying for grants,” she said. “When I went to college there were only a few female professors, and I can’t think of one that was openly part of the LGBTQ community. So I want to let students that are part of that community know that someone like them is doing this work and is here for them.”

Baker said engaging younger researchers across disciplines – especially those with diverse perspectives and lived experiences – would be crucial when solving these issues and working to address larger ones like climate change.

“We are talking about completely changing how one of our biggest infrastructure systems operates with implications for transportation, water and many aspects of everyday life in the U.S.,” she said. “To do that we want and need everyone’s help.”

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Research explores how electric vehicle adoption may impact vulnerable communities

Anonymous — Tue, 09 Mar 2021 20:40:21 +0000

Research explores how electric vehicle adoption may impact vulnerable communities Anonymous (not verified) Tue, 03/09/2021 - 13:40

Researchers at the 91��Ƭ��AV are exploring how widespread use of electric vehicles in the future may impact vulnerable communities.

The work is funded by a new seed grant from the Resilient Infrastructure with Sustainability and Equity Interdisciplinary Research Theme and is led by Assistant Professor Kyri Baker from the Department of Civil, Environmental and Architectural Engineering.

Mass adoption of electric vehicles could be a big step toward addressing climate change globally, as traditional engines are a big source of emissions. Bloomberg reported that “of the 1.8 billion tons of greenhouse gases produced by transportation in the U.S. in 2017, 59 percent of it came from passenger cars and light-duty trucks” alone. But electric vehicles also still currently require a significant amount of energy to operate. Charging a single electric vehicle can consume more energy than a house consumes in a whole day, Baker said. That kind of demand has implications for our power generation and distribution infrastructure that need to be addressed and planned for holistically.

At the same time, electric vehicles do not contribute to gasoline sales taxes, which support road maintenance and – potentially – construction of the new physical infrastructure like charging stations that will be needed to support them. That means those who can’t afford newer electric cars may be indirectly paying for infrastructure they aren’t using or see their utility bills rise as supply and demand dynamics shift with increased ownership. Baker said that even before the pandemic, the Energy Information Administration reported that 30 percent of households faced some sort of “energy insecurity,” such as forgoing food, living in uncomfortable temperatures, or have received disconnection notices. She added that roughly half of Black, Hispanic or Latino, and Native American households currently face energy insecurity.

“This project is a little different because it looks at those infrastructure requirements and what we need to reach some of these sustainability goals, but it also really explores how those choices will impact people on the ground,” she said. “That aspect of equity and inclusion is particularly important here and something we are excited to explore.”

Baker is working with Assistant Professor Cristina Torres-Machi and Associate Professor Amy Javernick-Will on this project along with postdoctoral researcher Constance Crozier and undergraduate architectural engineering student Liam Daniel.

Torres-Machi agreed that the social equity questions in the project were crucial and said the team would be looking at data on vehicle ownership, transportation modes and road conditions as well as household use and payment for those services.

“I am particularly interested at evaluating how these kinds of environmental initiatives (such as adopting electric vehicles) may negatively impact the condition of our transportation infrastructure and cause higher disparities in our communities,” she said.

Above: Graphics from Baker's group show electric vehicle adoption in Colorado (left) which is mainly centered along the Front Range next to the median income levels (right) in the state which are more evenly distributed. Part of this seed grant funded research will look at how increasing EV adoption is hurting low-income communities, specifically the potential of increased EV adoption to impact electricity prices and fuel taxes.

The Interdisciplinary Research Theme, a collaborative research effort housed within the College of Engineering and Applied Science, is uniquely positioned to explore these kinds of issues. Formed in July 2020, it brings together researchers and expertise in disaster resilience, sustainable design and social justice from across the engineering college and broader CU Boulder campus. Altogether, there is potential for interaction in the IRT across many areas of study, including engineering, geological sciences, business, economics, law and public health. Such a combination is unprecedented and puts the group in a unique leadership position globally, as there is no current center that features all of these topics and has all of these centralized resources at its disposal, researchers said.

IRT Director Shideh Dashti said the project is a great example of the work that will be coming out of the center over the next few months.

“This grant combines sustainable design with social justice considerations, which was a top priority for us when developing the theme,” she said. “Kyri’s team is well-positioned to achieve their goals, and this work will prove useful in a variety of arenas in the very near future.”

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What went wrong with Texas’ power grid? A Q&A with CU Boulder experts

Anonymous — Mon, 22 Feb 2021 22:47:31 +0000

What went wrong with Texas’ power grid? A Q&A with CU Boulder experts Anonymous (not verified) Mon, 02/22/2021 - 15:47

On Feb. 13, a severe winter storm swept across Texas and nearby southern states, bringing sub-zero temperatures and snowfall as far south as the border with Mexico. The polar air that descended on Texas lasted many days, leading to a statewide crisis as energy grids failed to supply enough power, fuels froze and water pipes burst.

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