For more than a century, the association for heating, refrigerating, and air-conditioning engineers has set the standard for the building industry on energy performance. Now, ASHRAE is prepared to walk the talk with a net-zero-energy building.
By Marc Lefkowitz, SWE Contributor
ASHRAE, the professional association that sets standards for indoor air quality and energy performance in buildings, completed its renovation of a 1970s-era building in suburban Atlanta to serve as its next global headquarters. The organization set an ambitious goal of operating the building at net-zero energy, meaning, it will produce as much energy as it consumes.
For the building, which formally opened Nov. 18, ASHRAE raised $10.3 million, including a $5 million contribution from NIBE Energy Systems Limited, a subsidiary of NIBE Heating, a producer of ground-source heat pumps headquartered in Markaryd, Sweden. The capital campaign succeeded on the strength of its vision, says Ginger Scoggins, P.E., ASHRAE treasurer and chair for the building headquarters ad hoc committee.
“We felt, as ASHRAE, that it was important to push the envelope,” Scoggins remarked. “We were able to take that building, which was pretty unremarkable when it comes to energy usage, and turn it into a net-zero-energy building.”
Scoggins is hopeful that ASHRAE will confirm that the 66,000-square-foot building meets its design specifications and hits its net-zero-energy goal: The building will be commissioned after it is occupied to determine whether the combination of a state-of-the-art HVAC system; an exterior finish insulation system (EFIS); and a dual, solar PV system meet its energy performance targets, including ASHRAE’s own Standard 90.1.
A mechanical engineer and president of Engineered Designs Inc., Scoggins noted that the building is designed to operate with a low energy unit intensity (EUI), which is calculated by dividing the total energy consumed by the building in one year (measured in kBtu or GJ) by the total gross floor area of the building (measured in square feet or square meters) on a scale of 1 to 100, with 1 representing the highest efficiency.
The conversation about how to reach goals like net-zero energy and EUI began in 2019 when ASHRAE determined that it had outgrown its current headquarters in Atlanta. With neighboring Children’s Healthcare of Atlanta expanding, ASHRAE accepted an offer to sell its former headquarters to the hospital.
Scoggins, who is ASHRAE president-elect (following the next board term), was asked to oversee the plan for the new headquarters. Retrofitting an existing building — which was constructed in 1978 and occupied by Recall Corp., which was acquired by data security firm Iron Mountain — to reach an EUI of 21, with a “stretch goal” of 17, will make a statement to ASHRAE’s 50,000 members about its confidence in the state of building science, she said. (By comparison, the median EUI score in the U.S. for a commercial office building is 52.9, according to the U.S. EPA.)
“Our hope is that people see it’s possible to take buildings like this and make them energy efficient,” Scoggins said. “Instead of building new, which has a much larger carbon footprint, it is possible to take an older building and convert it.”
Part of the challenge of meeting an EUI of 21 with this building, Scoggins said, was presented by the small size of the windows, which did not provide sufficient daylight to meet ASHRAE’s Standard 90.1 on window-to-wall ratio. In order to bring in more daylight, 18 skylights were installed on the roof, and the window-to-wall ratio was reconfigured. Penetrations through roof and exterior walls impact the energy performance of the building’s envelope because they allow more energy to escape through air transfer. But, they were more than compensated for by the selection of energy-efficient windows, the EFIS cladding, and an innovative HVAC system, she said.
“Really, that is how you should approach net zero,” she said. “It’s about getting energy consumption as low as possible and whatever is left you add renewables.”
“What I’m really excited about is the very advanced controls and data that is being gathered to set that building up to easily evolve as a net-zero-emissions building…that is what is groundbreaking about what we are doing as an organization.”
– Sheila Hayter, P.E., former ASHRAE board president; laboratory program manager, National Renewable Energy Lab
Surmounting hurdles and looking to the future
In order to reach net-zero energy, the existing building’s natural-gas-fired boiler was jettisoned in favor of an all-electric system. The power plant is built around six water-source heat pumps that reduce energy demand by cooling water with the constant, 55 F (13 C) temperature underground before feeding it to a chiller and a mechanical ventilation system that captures joules of energy from the stale air that is expelled from the occupant space — the energy transfer powers radiant panels for air conditioning. Electricity will be generated on-site from the rooftop and ground-mounted photovoltaic solar energy system.
One potential hurdle to reaching net-zero energy comes from investor-owned utilities who cap the amount of distributed energy generation in their interconnection agreements, such as Georgia Power’s cap on solar power supplied back to the grid at 250 kilowatt/hours. It was a constraint on ASHRAE, Scoggins said, adding that they maxed out what was allowed (in AC power supply) and then added 331 kW in solar PV in DC power with the installation of an inverter. It will bring their total on-site power generation to 457 kWh per year.
“We felt, as ASHRAE, that it was important to push the envelope. We were able to take that building, which was pretty unremarkable when it comes to energy usage, and turn it into a net-zero-energy building.”
– Ginger Scoggins, P.E., ASHRAE treasurer and building ad hoc committee chair; president, Engineered Designs
“We hit a lot of walls of what we are allowed to do from Georgia Power,” Scoggins, a Raleigh, North Carolina, native, observed. “Which is a little surprising,” she added. “You would think it would be cheaper to build PV than a new, fossil fuel-burning facility.”
ASHRAE was also taken aback by the cost to service a loan for the solar panels, she added. While most customers for solar panels are finding favorably low interest rates to enter into third-party-run power purchase agreements, ASHRAE was quoted a 9% interest rate to lease the solar panels. Eventually, they found a rate to purchase the solar panels with a payback period of five years, Scoggins said, a more favorable return-on-investment.
“As energy becomes more expensive and as PV gets cheaper, which it is and will continue to be now with (the federal government) offering incentives and tax credits, we should be encouraging companies and utilities to do more,” Scoggins said, adding that a lower carbon intensity for their energy supply was also a goal of the organization.
What is most encouraging to Sheila Hayter, P.E., 2018-2019 ASHRAE board president and laboratory program manager at the National Renewable Energy Lab (NREL), is not that the ASHRAE building reaches net-zero energy, but the tech powering its energy monitoring.
“I knew a net-zero-energy building could be built,” said Hayter, referring to NREL’s meeting the challenge laid out by Congress to build a net-zero-energy building at the same cost per square foot as a commercial building in its region in 2010. “What I’m really excited about is the very advanced controls and data that is being gathered to set that building up to easily evolve as a net-zero-emissions building. So that when it is time to be part of a larger system, it is capable of being part of that ecosystem. That is what is groundbreaking about what we are doing as an organization.”
Hayter explained that the ASHRAE building’s remote monitoring and analysis of building performance, with an online dashboard to show occupants real-time information about energy consumption, is an important part of meeting the net-zero-energy goal.
Does she view the reliance on land, in ASHRAE’s case, part of an 11-acre campus for solar PV, as a hurdle for producing more net-zero-energy buildings?
“Since (ASHRAE) had the land, we can put (solar PV) on it,” she explained. For the same building in an urban setting to achieve net-zero energy, the challenge is, “What’s worth more, the value of clean electricity generation by a PV system or the land that you could do something with?”
Improving the efficiency of solar power so that the availability of land is not a bottleneck in expanding net-zero energy is a research area that NREL is exploring, Hayter said. She noted a research project operated jointly by NREL and Colorado State University to explore the “food, energy, water nexus” or the highest and best use of land.
“They are figuring out, how do you install a ground-mounted PV system where you could farm under it,” she said, adding that the experiment is based on small-scale farming. “They are finding that they have to irrigate less because there’s less evaporation.”
The ASHRAE global headquarters is a natural progression from the renovation of its former headquarters in Atlanta in 2010, which earned a U.S. Green Building Council LEED-Platinum rating.
“Most of the buildings that will be in use by 2050 are around today, and many are not functioning to their fullest capacity,” Scoggins said.
Trailblazing, for the next generation
Scoggins and Hayter have managed to navigate the specialized, male-dominated sector of mechanical engineering, which confers only 15.7% of B.S. degrees to women, according to the American Society for Engineering Education.
“Either you’re in it and you love it, or you realize this loneliness of being the only one,” Scoggins said. “I probably felt that way when I was younger, that feeling of not being taken as seriously.
“It’s interesting to me that there aren’t more women who are mechanical engineers,” she mused. “Women are good logical thinkers and multi-taskers.
“I’ve done a lot of career days, and I think there’s this idea that mechanical engineers are going to be working on cars or engines of some type. So, there needs to be more education on how broad mechanical engineering is.”
Hayter was the second woman to hold the title of president of ASHRAE — five years after her predecessor, Lynn Bellinger, P.E., reached the milestone as the first woman to hold the post in the then-115-year-old association’s history.
“[Being named president] was a surprise, but satisfying,” she said. “Other women in the industry tell me they feel empowered and motivated to pursue leadership roles, and if that’s something I could help with, if I can help someone else, then I’m happy to do that. There are more and more women filling leadership roles at the grassroots level, which is nice to see.”