Latest / NOXTalks / The Metric Your Frameworks Miss: After-Hours HVAC Waste

Transcript

The Metric Your Frameworks Miss: After-Hours HVAC Waste · NOXTalks

• 0:07
  SPEAKER_01: Welcome to Knox Talks, the AI-generated podcast exploring the groundbreaking ways technology shapes our built environment.
• 0:14
  SPEAKER_01: Today we're diving into a kind of energy waste hiding in plain sight.
• 0:18
  SPEAKER_01: HVAC that runs long after everyone's gone.
• 0:22
  SPEAKER_01: Picture it, seven on a Friday night.
• 0:24
  SPEAKER_01: The last tenant left hours ago, but somebody on the third floor hit a wall button that afternoon, and the AC's been running ever since.
• 0:33
  SPEAKER_01: Nobody knows who hit it, nobody will ever know it ran, and the cost gets spread across every tenant by floor area, whether they caused it or not.
• 0:41
  SPEAKER_01: That's the after hours blind spot.
• 0:44
  SPEAKER_01: Let's set the scene.
• 0:46
  SPEAKER_01: The International Energy Agency says building operations make up roughly 26% of global energy-related greenhouse gas emissions, and the U.S.
• 0:55
  SPEAKER_01: Department of Energy puts HVAC at about 30% of a commercial building's total energy.
• 1:00
  SPEAKER_01: Within that footprint sits a category of waste that's avoidable, behavioral, and, here's the kicker, often low cost to reduce.
• 1:09
  SPEAKER_01: So why is it invisible?
• 1:11
  SPEAKER_01: The big frameworks, Energy Star Portfolio Manager, Lead for Operations and Maintenance, BOMA Best, GRESBY, have done real work raising the bar on whole building reporting, but none of them appear to require after hours HVAC bookings as their own named reportable metric.
• 1:29
  SPEAKER_01: So that runtime disappears into the whole building total, and invisible waste doesn't get managed, and it matters more now.
• 1:37
  SPEAKER_01: Building performance standards are tightening across North America.
• 1:40
  SPEAKER_01: New York's Local Law 97, Boston's BERDO, DC's BEPS, Toronto's reporting by law, and Vancouver's greenhouse gas and energy limits, though enforcement there's currently paused.
• 1:53
  SPEAKER_01: If you can't separate occupant behavior from whole building data, you're flying blind on emissions you could actually correct.
• 2:00
  SPEAKER_01: Now the fascinating part, this is really a people problem, not an engineering one.
• 2:06
  SPEAKER_01: The systems delivering after hours comfort were never built for accountability.
• 2:10
  SPEAKER_01: Those old push-button overrides?
• 2:12
  SPEAKER_01: Easy to hit, they rarely log who press them, and they run far longer than anybody needs.
• 2:18
  SPEAKER_01: And it's not just legacy gear.
• 2:21
  SPEAKER_01: Plenty of modern VRF and split systems scatter wall controllers across a floor, on, off temperature, fan speed, the works.
• 2:29
  SPEAKER_01: Even tied into the building system through a gateway, if those controls aren't locked out, a tenant can restart a unit after the scheduled shutdown.
• 2:38
  SPEAKER_01: And depending on the control sequence, that one override can keep the unit, shared outdoor capacity, or interlocked fresh air plant running till the next scheduled event.
• 2:48
  SPEAKER_01: Your control system says the building's off, the space says otherwise.
• 2:52
  SPEAKER_01: That's the control authority gap.
• 2:54
  SPEAKER_01: There's a psychology piece too.
• 2:57
  SPEAKER_01: We treat anything we can't see or measure as basically unlimited, and HVAC's the perfect victim.
• 3:03
  SPEAKER_01: You feel comfort or you don't.
• 3:05
  SPEAKER_01: But the chillers, boilers, and compressors behind it?
• 3:09
  SPEAKER_01: Up on the roof, out of sight, out of mind, out of budget consciousness.
• 3:14
  SPEAKER_01: So does fixing accountability move the needle?
• 3:17
  SPEAKER_01: Here's a real-world example.
• 3:19
  SPEAKER_01: A premium office building in Auckland, New Zealand, 152 Fanshaw Street, around 6,500 square meters.
• 3:28
  SPEAKER_01: PMG funds bought it in 2021.
• 3:31
  SPEAKER_01: It had classic legacy buttons.
• 3:33
  SPEAKER_01: Press 1 and HVAC could run up to 12 hours, regardless of need.
• 3:39
  SPEAKER_01: No attribution, no time limits, no reporting.
• 3:42
  SPEAKER_01: So they ran a broader program, corrected metering, better control visibility, a new fresh air handler, LED lighting.
• 3:51
  SPEAKER_01: But the key move, they swapped the buttons for a cloud booking system, named user, default time limits, monthly reports by tenant and floor.
• 4:00
  SPEAKER_01: Now the result, and it's worth being precise, average monthly after hours HVAC electricity use intensity dropped 48% across a 34-month data set.
• 4:11
  SPEAKER_01: That 48% isolates after hours electricity specifically.
• 4:15
  SPEAKER_01: So it's the figure tied most directly to the switch from anonymous overrides to name bookings.
• 4:20
  SPEAKER_01: The broader program is a separate story.
• 4:22
  SPEAKER_01: It delivered a 5.5 star neighbors New Zealand rating and cut total site energy 11.8% in 2023 versus 2022.
• 4:32
  SPEAKER_01: Worth keeping those layers distinct.
• 4:35
  SPEAKER_01: One more fun fact.
• 4:37
  SPEAKER_01: A 2017 study found that moving an office from 22 to 25 degrees Celsius didn't significantly affect cognitive scores in a small sample of office workers.
• 4:48
  SPEAKER_01: And based on prior research cited in that paper, that three-degree lift could imply roughly 18% lower daily cooling energy, all else equal.
• 4:57
  SPEAKER_01: So a lot of our comfort norms might be convention, not physiology.
• 5:01
  SPEAKER_01: So what do you do?
• 5:03
  SPEAKER_01: Five steps.
• 5:04
  SPEAKER_01: One, separate the data.
• 5:06
  SPEAKER_01: If it's buried, you can't manage it.
• 5:08
  SPEAKER_01: Two, put named users behind every request, that signal can change behavior.
• 5:13
  SPEAKER_01: 3.
• 5:14
  SPEAKER_01: Set smart defaults, short durations, confirmation prompts, auto-expiry on empty rooms.
• 5:20
  SPEAKER_01: 4.
• 5:21
  SPEAKER_01: Report back monthly by tenant or department.
• 5:24
  SPEAKER_01: And five, connect it to your sustainability goals.
• 5:28
  SPEAKER_01: After hours runtime is operational carbon, treat it like one.
• 5:32
  SPEAKER_01: Whether the frameworks catch up or not, the buildings that get ahead now will have cleaner data, fairer cost allocation, and a stronger sustainability story.
• 5:42
  SPEAKER_01: That's it for today.
• 5:43
  SPEAKER_01: Until next time, keep an eye on what your building's doing after everyone's gone.