HVAC & BMS

The DVM is the primary instrument for in-duct deployments. It installs via a Devlabs-designed sampling spear that passes through a small access hole in the ductwork and draws a representative sample directly from the airstream. Power comes from the 9–24 V DC supply already available at the BMS controller panel — no additional power supply required. The DVM exposes a comprehensive sensor suite via RS-485 Modbus RTU (slave address 107, 9600 baud, 8N1): PM1/PM2.5/PM4/PM10, particle number concentration, CO₂, eVOC index, NOₓ index, and temperature and humidity. Two derived composite indices — CAI (Clean Air Index) and VG (Ventilation Degree) — are also available on the register map and can be read directly by a BMS controller for demand-controlled ventilation logic without custom calculation.

The DVM simultaneously transmits the same data via LoRaWAN to the Devlabs platform. This independent data path is fully isolated from the building's OT/IT network — useful in OT environments where network segregation policies prevent cloud routing of BMS data, and valuable during commissioning when platform visibility is needed before BMS integration is complete.

For environments requiring broader air quality monitoring — plant rooms, server halls, ambient office or laboratory spaces — DGEM units provide complementary outdoor or ambient PM, gas, and weather data from the same platform interface as the DVM units.

For facilities with areas outside BMS scope — remote plant rooms, cold stores, server racks, or energy sub-metering points — Devlabs LoRaWAN Systems provides a pre-provisioned wireless sensing layer that integrates into the same Devlabs platform dashboard.

Deployment scenario

A facilities management team responsible for a portfolio of commercial office buildings deployed DVM in-duct monitors across twenty air handling units serving five buildings. Each DVM was wired to the existing BMS Modbus RTU bus using standard 2-core screened cable; CO₂, temperature, humidity, and the VG index were mapped to the BMS controller and used to control fresh air damper positions for demand-controlled ventilation. The DVM's independent LoRaWAN data feed gave the facilities team real-time visibility into air quality conditions from the Devlabs dashboard — without requiring access to the BMS SCADA system.