Part 1 of 2: Commitment to Zero Energy
Recently we talked with three people from McKinstry about the firm’s activities in transforming the building industry, including its growing participation in launching ZE facilities: Craig Hawkins, Commissioning Project Director; Brad Liljequist, Zero Energy Senior Program Manager; and Geremy Wolff, Regional Director, Technical Services for the Pacific Northwest.
BCxA corporate member, McKinstry, has nearly two dozen zero-carbon/zero energy projects underway. Of the more than 111 companies, including major players Amazon, JetBlue, Unilever and Microsoft, that have joined the Climate Pledge, 8 are construction-related firms. McKinstry was the second to join in September 2020. The Pledge is a commitment to implement, measure and sustain decarbonization strategies to achieve net zero annual carbon emissions by 2040.
We wanted to add real-world context for readers on what Zero Energy (ZE) is for a company that works with clients to deliver it — what’s happening, why it matters for commissioning providers, and how commissioning overlays or intertwines with ZE.
The conversation started out with a general observation that a lot of people think it’s not achievable, or at least not sustainable. “That’s how I thought of it at first,” said Hawkins. “It’s the golden ring that everybody’s reaching for but they don’t know how to get there…and they think it’s not possible.”
And, according to Liljequist, “It’s hard, but not that hard. In the last decade it has transitioned from ‘impossible’ to the evolution of technology that makes it possible. While it’s not widespread, it is now mainstream, in terms of people’s ability to deliver it …. we can do it.”
The Significance of Commissioning in Meeting EUI Performance Goals
Unlike traditional new construction energy use analysis, ZE is not about modeled performance, it’s about actual performance. In a way it could be considered "Commissioning Plus”, i.e., the facility and integrated systems are verified to startup properly, operate correctly, and perform according anticipated energy use intensity (EUI), which measures a building's annualized energy efficiency.
In order to achieve and maintain real metrics for ZE, energy use must be measured regularly and in a consistent way. Generally, owners and facility staff don’t have any idea what the real EUI is, and they simply base their calculations, if any, on an energy model based on the original facility design (in the case of new construction).
Another ZE issue is related to limitations within building and energy codes, in that they typically don’t require performance measurement post-occupancy, over time. To some degree state and city benchmarking requirements around the country help with performance measurement, but so far there are few regional or even local policies for ZE facilities.
That very fact may cause readers an initial sigh of relief, but wait. There’s a role for people here, and there’s more about this emerging market on its way to you, courtesy of recent federal government mandates.
What makes ZE Building Commissioning Different?
The commissioning process for ZE facilities is slightly different from traditional commercial building commissioning. One big difference is having a commissioning provider present for the first year of operations, to perform due diligence on “all the little things” that add up to EUI — not just meeting the requirements of the OPR/BOD but also verifying the actual, rather than just modeled, EUI.
CxP Post-Occupancy Presence. It’s not common for commissioning providers to return to the building after occupancy to test performance after people show up. Post-occupancy Cx isn’t often requested — Owners usually think of commissioning as a design/construction activity.
Even with spending the first year analyzing and commissioning operations to meet the EUI goal, it’s recommended not to use first year performance to show that you have a good baseline. Liljequist reminds us that “EUI variability in a building can be due to occupancy, especially over the recent year-plus; is it full or empty, or somewhere in between? Plug loads and occupant workspace density make a huge difference in EUI.”
“We always try to be engaged post-occupancy, which is especially important because you need to commission against all operating conditions. If we’re not engaged across the four seasons, we often have to fake the conditions to see how the building responds to warmer and colder temperatures as well as with varying occupancy loads. The rubber meets the road when people get into the building.” says Wolff.
Different/Unfamiliar Systems. Commissioning providers for ZE facilities often run across unfamiliar systems and combinations of systems. It’s “not just standard equipment, but a bunch of different modes and combinations” — data analytics is necessary to determine the right mode to be running in, given current conditions. Finer tuning during commissioning is really important. For example, with electrical switching, commissioning providers will need to be dialed in on how the systems work because, as we all know, the systems are not always working right. They must understand the interaction between motorized/automated window shades that depend on a photocell on the roof that’s reading how cloudy or bright it is.
“A lot of the commissioning issues for ZE are in the finer details, expanding the circle of what we’re looking at, i.e., voltage, and things that are electrically-driven instead of mechanically driven,” says Liljequist. “5,000 little things that add up to a lot.”
Holistic Cx Participation and Handoff. ZE adds complexity that also requires a strong partnership with the engineers who design it. They are often still focused on occupant comfort as a priority. However, if you change a setpoint during testing without recognizing a phase change material is the primary source (one that changes state, e.g., from solid to liquid with temperature variation, as in CO2), as opposed to a differently fueled heat pump, there will be a problem.
“We need to be thinking differently about how we approach these projects, and integration of the complex systems to meet the Owner’s goals well beyond handoff,” says Hawkins. “A big difference I see is the envelope itself – orientation of the building, where everything is located … for example, most people think of building enclosure commissioning (BECx) as a blower door test. Everyone on the project team needs to understand what ZE means, and the connections, the energy transference that can happen, but the envelope itself makes the difference between ZE and any other building.”
By far the biggest energy load in a ZE building is plug loads. according to Liljequist. “We’ve been focused on working with clients about cataloguing everything they’re going to move into the building in terms of energy using equipment. heat pumps, chillers, good envelope and IT. Your IT load is going to be bigger than your HVAC load. So we’re rolling up our sleeves to decide, what does our program look like around that?”
In one project there were changes made to sequences during commissioning by a third party – the gas consumption was not tracking right; after a few months we figured out that was the problem. By changing the sequences of operation, the provider was trying to make it work, but that resulted in a problem that was finally solved after 6-9 months.
“It’s important to know that a building performs according to its claim,” says Liljequist. “I see a big opportunity for commissioning providers to own that. It’s especially important in the design process to understand how it all gets tied together. Ideally the design team starts with the commissioning provider on Day One – when they all understand the building and assumptions that were made, they are able to provide a substantial handoff at the end.”
It’s critical to make sure there’s a very open and transparent transition handoff between the design team and commissioning provider (and Owner’s facility staff), doing a thorough walk, slowly and carefully, around how the building is designed, covering any assumptions that were made about things like thermal gain and areas of uncertainty.
The Role of Humans in Achieving ZE
What we’re finding now is that we should have spent more time talking to people and letting them know how they will fit into the process – i.e., how does that affect the people – their role in ZE starts up front. We’ve been talking about how important it is to start commissioning at the beginning for 30 years, but with ZE you have got to start at the very beginning.
We like the concept of an Owner's employee or representative who is an "Energy Concierge" for ZE buildings. This individual would deliver a cluster of services necessary to sustain ZE after design and construction and enable the human interaction necessary to maintain communication with occupants and other stakeholders.
When is Cx Completed in ZE Facilities?
“As a strategic partner with our clients in design, construction and operation, we also need to focus efforts on where the savings are coming from, knowing that an Owner doesn’t necessarily have the budget necessary to meet the EUI of ZE,” says Wolff. “We also need to focus on technology and strategies for heat pumps, air distribution; higher performance, peaking, and so on.”
“The finish line,” says Hawkins, “is 50+ years from now when they tear down the building. Owners need to understand that commissioning is not an event, it’s a process. It’s done when the building is done, in 50+ years. That’s especially important when commissioning a high-tech ZE building.”
Stay Tuned for Part 2: Zero Energy/Carbon and Testing a ZE/ZC “Ecosystem”