Modern building automation systems (BAS)
face a widening gap between increasing intelligence and aging physical infrastructures.
While modern HVAC and fire-safety sensors demand high-frequency data streaming and
millisecond-level response times, the legacy serial networks used to transport this data
are struggling with bandwidth bottlenecks, high latency, and complex multi-conductor
wiring. This whitepaper identifies the critical risks associated with these legacy
architectures and proposes a scalable answer: single-pair Ethernet (T1L and T1S). By
analyzing the technical advantages of T1L for long-reach HVAC control and T1S for
deterministic fire-safety loops, this document demonstrates how engineers can
potentially reduce cabling costs by up to 50% while providing a native IP-based
foundation. The result is a unified, secure, and potentially future-proofed building
architecture that improves energy performance and life-safety compliance through the
power of Ethernet.