Image in modal.

Decarbonization is one of the major trends in the U.S. and many feel that it is a vital step towards ensuring a sustainable future for the country. To shed more light on the topic, a panel discussion was held at the AHR Expo in Atlanta, Georgia, to explore the current state of decarbonization in America, as well as discuss the challenges, opportunities, and solutions that lie ahead.

Kyle Gargaro, editorial director of the HVACR Group at BNP Media, moderated the panel, which consisted of Donald Horn, FAIA, LEED, deputy director at the Office of Federal High-Performance Green Buildings at the General Services Administration (GSA), Washington, DC; Kent Peterson, PE, vice president and COO at P2S Inc., Long Beach, California; Kevin Edstrom, senior MEP manager at Hines, Houston, Texas; and Luke Leung, principal at Skidmore, Owings, and Merrill, Chicago, Illinois.

Decarbonization is about reducing greenhouse gas emissions, with the ultimate goal of getting to zero carbon emissions.
- Kent Peterson, PE
Vice president and COO
P2S Inc.

Carbon Types

Gargaro started the panel discussion by asking the experts what decarbonization means, particularly as it relates to HVAC. Peterson jumped right in, noting that decarbonization is about reducing greenhouse gas (GHG) emissions, with the ultimate goal of getting to zero carbon emissions.

“That doesn't mean tomorrow, but a lot of people have set targets that by the time we get to 2050, we need the entire built environment to be at zero greenhouse gas emissions,” he said. “And that's on both the embodied carbon side and on the operational carbon side. We're not just talking about the new buildings, we're talking about even the existing buildings.”

To better understand what these sources of carbon mean, Leung explained that the definitions may change, depending on the regulation and framework used under the current international framework. However, broadly speaking, operational carbon is the carbon emissions that result from the operation of the building, including energy consumption and the emissions associated with that.

“Embodied carbon is the material used to build the chillers and the buildings,” said Leung. “If you go by [European standard] EN 15978, refrigerant is considered to be embodied carbon, because it comes with the building. Leakage of refrigerant is considered to be a repair of the embodied carbon of the building.”

There is also end-of-life carbon to consider, which as the name implies, occurs at the end of the operational stage, said Horn.

“What happens then? What about recycling and reuse and what type of disposal happens? And what are the emissions associated with that?” he asked. “Total life carbon is usually broken up to be embodied carbon — mainly referring to the manufacturing and production upfront — and operational carbon. End of life hasn't gotten quite as much attention yet.”

Peterson noted that manufacturers are working diligently on their environmental product declarations (EPDs) and are trying to determine how embodied carbon fits into the value chain as it comes into the built environment. He predicted that within the next three to five years, there will be requirements for embodied carbon disclosures happening in almost all the state jurisdictions.

Leung said that’s already happening in California and New York, where embodied carbon information has to be provided as part of the whole life carbon information for a building.


Clean Power

On the topic of whether the U.S. can produce enough electricity in a clean and timely manner to fit the corporate decarbonization narrative, Peterson said that he expects innovation will help this progression.

Power lines.

CLEAN POWER: The federal government is leading the charge for clean power, with its sustainability plan that requires 100% carbon pollution-free electricity by 2030. (Staff photo)

“We're in 2023 today, and we're talking about 2050 goals,” said Peterson. “The innovation curve right now within the world of technology has become amazing. It's going to happen on the HVAC product side, it's going to happen on the grid side, and it's going to happen on the storage side.”

As far as the grid is concerned, right now it is sized to handle peaks, which usually occur in the summer. But as electrification of homes, cars, and buildings picks up, peaks will happen in the winter as well, said Peterson.

“Storage is going to become an issue, and we're going to have to look at what the solution is,” he said. “The ultimate solution, by the time we get the 2050, is not going to be solar and wind being everything. They might play a role, but there's going to have to be 24/7 affordable electricity for everyone around the world in order to really make this happen.”

The federal government is leading the charge for clean power, with its sustainability plan that requires 100% carbon pollution-free electricity (CFE) by 2030, said Horn. Utilities have confirmed that the capacity is there and that they will be able to provide CFE by the deadline, he said, so the federal government is moving forward to make this happen for its electricity purchases.

While decarbonization is a challenge, it is also an opportunity to provide leadership, not only in the U.S., but around the world.
- Luke Leung
Skidmore, Owings, and Merrill


When it comes to decarbonizing new or existing buildings, the measures implemented have to be cost effective in order for end users to get on board. That is usually achieved through efficiency, said Peterson, adding that heat recovery plays an important role in making the numbers work.

“We have to change our entire thought process because we grew up understanding from an economic perspective, that natural gas was cheap. Boilers were cheap,” said Peterson. “When we go to any type of these heat pump type technologies, or even the heat recovery technologies, we're talking six to eight times more than the first cost of the equipment. So this is where the economics really change, where we really have to use heat recovery technology in these buildings.”

Peterson added that it is also important to understand that electrification is not just about replacing fossil fuels, but reducing fossil fuel emissions. “There are carbon sequestration technologies that will be developed. In fact, they're already being tested in buildings in New York City, where the existing boiler systems can remove 70% of the carbon emissions. So there's a lot of new technology that will come out.”

But cost is definitely an issue, said Edstrom, and it’s something that his company struggles with on every job.

“It’s not just MEP systems but every component in the building,” he said. “Also, there's a space premium to go to a heat pump heating system, for example, compared to a traditional boiler system, so we're having to plan our buildings a bit differently. Another piece is the data that we're trying to gather. Just getting consistency across not just the mechanical systems, but the whole industry so that we have a good picture of what went into building the building and how much carbon was emitted in that whole process. Then going forward, how much is it going to take to operate the building throughout its whole life?”

ASHRAE hopes to answer those questions through its building decarbonization task force, which Peterson chairs. The group plans to offer guidance on topics such as the use of heat pumps in various regions throughout the United States, including in colder regions, as well as how to start retrofitting existing buildings. For example, what steps should be taken and what considerations should be kept in mind.

“We have a guide that's being put specifically together on dealing with these existing building retrofits,” said Peterson. “We look at the proper sequence of going through that building and coming up with a plan. It's not a retrofit if it has to happen tomorrow, but we found that if you have a plan on what you're going to be doing over the next 20 years, when it gets end of life on equipment, you can make those proper decisions and make envelope improvements and other types of things that need to be done. We're also putting together some key guidance on whole life carbon in MEP systems, or what we call building services. That's direly needed in the U.S.”

While decarbonization is a challenge, it is also an opportunity to provide leadership, not only in the U.S., but around the world, said Leung.

“There is no standard out there, but mature people have gotten together to develop the product category rule (PCR), which defines how to quantify the embodied carbon, so that piece is done,” said Leung. “But we have so many more rules we have to define. It’s a challenge, but it's also an opportunity for us to get together to define those rules to create this better future. And there’s gravy on top, as EPA is providing $350 million to do that. So look, we could do these things together, make some money, have some fun, and create a better future for our kids.”