If you spent time in the quieter corners of AHR Expo 2026, you likely heard the same three letters come up repeatedly: T1L.
Many of the conversations around 10BASE-T1L felt less like product announcements and more like early signals that the foundational layer of building controls is under renewed scrutiny.
At a basic level, T1L offers a two-wire, long-distance, Ethernet-based field network that may allow legacy cabling to be reused while supporting IP communication. That alone explains much of the interest. The attention, however, appears to be driven by several broader industry pressures:
- Growing interest in closer interaction between buildings and the electrical grid
- Ongoing skilled labor constraints that favor simpler installation models
- Increased demand for system-level visibility, particularly in retrofit scenarios
In that context, T1L is being discussed not just as a new option but as a potential enabler for broader modernization efforts.
Different Stakeholders, Different Perspectives
One theme that emerged in Las Vegas was not consensus, but contrast. Different parts of the industry appear to be evaluating T1L through very different lenses.
- Owners and facility managers tend to focus on return on investment, long-term flexibility, and minimizing future dependency on single vendors.
- System integrators often point to the promise of easier commissioning and longer network runs, while also noting concerns about supporting another emerging network type.
- Manufacturers are weighing how closely to align with open implementations versus differentiated ecosystems.
- Consulting engineers remain cautious, with many indicating that proven, multi-vendor deployments will be important before broader specification.
These perspectives reflect differing priorities rather than disagreement about the technology itself.
A Question of Direction, Not Capability
From a technical standpoint, the underlying Ethernet technology behind T1L is well understood.
The more open question is how it will be implemented and governed.
Will T1L evolve into a widely adopted, vendor-neutral device-level network that supports interoperability and long-term choice? Or will it fragment into partially compatible implementations that limit those benefits?
The answer is unlikely to come from standards documents alone. It will depend on market behavior, collaboration between vendors, and how strongly openness is prioritized by owners and specifiers.
Early Signals, Not Final Outcomes
What emerged at AHR 2026 felt less like a conclusion and more like an early checkpoint.
T1L reflects growing recognition that modernization at the device and field-network level deserves renewed attention. Its long-term impact will depend on how consistently it is implemented and how openly it is supported across the ecosystem.
We welcome your perspective.
Did you encounter T1L at the Expo?
Is an open, device-level Ethernet approach relevant to your current projects?
On the floor at AHR, I conducted a few quick interviews to try and capture how the industry is shifting quietly and quickly.
I had a quick chat with Steve Fey of iSMA CONTROLLI US about his conversations at hashtag#AHR2026
Imagine going beyond Ethernet’s 100-meter limit without needing extra routers or switches. T1L uses just two wires, reusing existing wiring in buildings and extending device distances without sacrificing speed.
For decades, our industry relied on protocols such as BACnet MSTP and Modbus RTU. They are great for miles of wiring, but slow and outdated for high-speed data needs. T1L offers 10 megabits per second over longer distances with fewer complications.
It’s a reminder that innovation often looks like a switch, not a revolution. Rethinking how we connect can unlock new possibilities.
