3 min read

PSA: Time to remove the overrides [Nexus Newsletter #76]

Plus digital readiness, defining the IDL, and the new Brick Consortium

Hey friends,

Let's start this week's newsletter with a public service announcement:

If you've overridden your building's ventilation control sequences to mitigate the risk of COVID-19, it's (probably) time to release those overrides.

You're (most likely) wasting energy, increasing operational costs, and having a negligible impact on occupant safety.

In April, at our monthly members-only Zoom gathering, indoor air quality (IAQ) expert Aaron Lapsley gave an excellent presentation on a data-driven approach to IAQ.

The highlight for me was some of the results coming out of studies by a company called SafeTraces. They've developed the technology to safely mimic how a pathogen travels through a building so it can be tested.

So what does the data say? As Aaron said on LinkedIn:

"Increased filtration and outside air levels are great for indoor air... BUT they are unlikely to make your building less risky for pathogen transmission, i.e. they are very unlikely to move the needle on people getting other people sick indoors.

Pathogen transmission risk is vastly more concentrated at the room level than via recirculation of air from central (or even fairly localized) air handlers."

That's because 99.99% of simulated pathogens don't make it back to the AHU from the human that sneezed or talked them into a room.

The CDC's and ASHRAE's guidance recommending building operators to throw their outside air dampers wide open was based on an understandably conservative assessment of the available science at the time.

But that time has passed, my friends.

It's time for all of you building operators out there to remove the overrides on the OA dampers and demand-controlled ventilation sequences.

What do you think?


PS: Tomorrow is our May member's gathering, where presenters from Brainbox AI, Clockworks Analytics, PassiveLogic, Mapped, and Facil.ai will showcase different types of AI and how they're being applied to real buildings today.

Join Nexus Pro now to get the invite immediately. You’ll also get access to the recording of Aaron's IAQ presentation (and the archive of all recordings).

At the Nexus

Here’s what we published this week:

🎙️ #051: Rachel Kennedy on digital device discovery (Dx³) and reflections on teaching smart buildings—We talked about what's new at Switch, including Rachel's new role as a Product Manager for the Dx³ offering and why Dx³ is valuable in the building digitization process.

Then we talked about what teaching the Nexus Foundations course has taught us about our industry and our hopes and goals for the course in the future. If you're wondering what the course is like, this is an inside look at where we're at as we gear up for Cohort 3.


Defining and exploring the Independent Data Layer—As a follow-up to recent newsletters Where are the API-first companies? (last week) and The API-first Data Layer, this members-only deep dive unpacks this concept further by defining the independent data layer, unpacking the nuances and unanswered questions, and updating the Nexus Vendor Landscape with this new category.

Signal vs. Noise

Only the best smart building resources we consumed this week…


The problems with smart buildings—Thought-provoking rant of an article out the UK. Seems to be specifically targeting the design & construction process and how it leads to poorly performing HVAC control systems.

“As has been said many times before, unmanageable complexity is the enemy of good performance. And nowhere is this more obvious than in air-conditioning control devices with so many features that they defeat everyone but the system provider.”


Brick Consortium Kicks Off—The creators of the Brick Schema have formed a non-profit governance/management organization and held a few events over the last few months to provide information. The slides are at the link above.

I must admit I don’t understand this. Perhaps someone can fill me in. I thought Project Haystack v4 was a response to Brick’s complaints about Haystack’s shortcomings. With Haystack v4 now released, I’m wondering why this other organization was needed?

That’s all for this week—thanks for reading the Nexus newsletter by Nexus Labs, a blog, podcast, membership community, and online school for smart people applying smart building technology—written by me, James Dice. If you’re new to Nexus, you might want to start here.