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Building Energy Monitoring System

Chiller plant to tenant riser. Into the BMS you already have.

A building energy monitoring system measures electricity consumption circuit by circuit across a commercial building, covering chiller plant, AHUs, lifts, lighting risers and tenant supplies instead of a single utility reading. Tech OVN uses Titan Class 0.5S meters that feed an existing BMS natively over BACnet/IP or BACnet MS/TP with no gateway, at ₹8,500–₹18,300 per measurement point.

A commercial and business energy monitoring system for offices, malls, hotels, hospitals and campuses. Class 0.5S meters on the circuits that matter — chillers, AHUs, lifts, lighting risers, tenant supplies, car-park charging — feeding your existing BMS natively over BACnet, and a portfolio dashboard if you want one. Monitoring a factory or process plant instead? Use industrial energy monitoring, which is built around motor loads and production lines.

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Building energy monitoring dashboard showing live consumption across chiller plant, tenant supplies and common-area circuits

At a glance

What it is
Circuit-level Class 0.5S electricity metering across a commercial building, feeding a BMS, a dashboard, or both.
Built for
Offices, malls, hotels, hospitals, mixed-use and campuses — single building or a managed portfolio.
BMS integration
Native BACnet/IP and BACnet MS/TP, plus Modbus RTU/TCP and MQTT. No gateway, no translation module.
Cost per point
₹8,500–₹18,300 per meter. No catalogue MOQ — a pilot can be one meter. Regular orders ship from stock.
Per-site infrastructure
None. No energy-server PC, data concentrator or per-site software licence.
Reporting
On-device CO₂ from a configurable grid factor — Scope 2 data for BRSR, CSRD and GHG Protocol.

A Building Bill Is One Number for Fifty Decisions

A commercial building arrives with one utility reading a month. From that single number a property team is expected to apportion CAM charges, answer a tenant who thinks they are overpaying, judge whether the chiller retrofit worked, and fill in an ESG disclosure. None of those questions can be answered from a total.

The gap is widest where the load is largest. HVAC is usually the largest single load in a commercial building, and chiller efficiency degrades quietly — fouled tubes, refrigerant loss, a failing compressor, pumps running at a fixed speed against a changed load. A chiller consuming 10% more than its commissioned kW/TR does not announce itself. It simply appears in the bill as weather, or occupancy, or nothing in particular.

Metering the circuits individually makes each of those questions answerable with data rather than argument — and because the meters speak BACnet natively, it does so without displacing the building management system you already run.

What to Meter in a Commercial Building

Six circuit groups, in the order we usually suggest metering them.

Chiller plant and HVAC

Usually the largest single load in a commercial building. Metering the chillers, AHUs and pump sets separately is how you see kW/TR moving away from the commissioned figure.

Tenant and common-area supplies

Separating landlord load from tenant load turns CAM charges from an apportioned estimate into measured kWh. It also ends the annual argument, because a disputed bill can be answered with interval data.

Lifts, lighting and small power

The circuits nobody meters individually, which is exactly why nobody can explain the base load. One meter per riser makes overnight and weekend consumption legible.

Standby and critical power

DG sets and UPS feeders metered continuously, so generator cost per kWh and backed-up load are known numbers rather than assumptions discovered during an outage.

Car park and EV charging

EV charging is becoming a material building load and often sits on the landlord's supply. Separate metering is what makes recovery from drivers or tenants defensible.

Kitchens, laundry and amenities

In hotels and malls these are concentrated, schedule-driven loads that respond well to measurement — and they are frequently left running outside operating hours.

It Feeds the BMS You Already Have

In commercial buildings the building management system is usually already installed, already commissioned, and not going anywhere. Honeywell, Siemens Desigo, Johnson Metasys and Schneider EcoStruxure Building all speak BACnet as their native protocol, and many energy meters do not — which is why metering retrofits so often arrive with a BACnet gateway per riser, each one a licence cost, a configuration file and a thing that can fail.

Every Titan meter speaks BACnet/IP over Ethernet or WiFi and BACnet MS/TP over RS485 natively, with no gateway or translation module. Alongside that it runs Modbus RTU, Modbus TCP and MQTT. The RS485 port carries Modbus RTU slave, Modbus RTU master or BACnet MS/TP — one role at a time, selected at commissioning — while the Ethernet/WiFi side (Modbus TCP, MQTT, REST API, BACnet/IP) runs separately.

So the BMS keeps doing control and gains a metering-grade measurement layer underneath it. If you would rather the data went somewhere else — a tenant-billing system, a portfolio analytics platform, your own cloud — MQTT publishes to any broker you configure, and no data path requires a Tech OVN server. The EMS vs BMS vs SCADA comparison sets out where each system's job starts and stops.

Class 0.5S matters here for a commercial reason, not a technical one: it is a tighter accuracy class than the Class 1 typically used on LT utility meters, so a tenant invoice generated from it is hard to dispute. (The class a utility needs for its own billing is set by the CEA metering regulations for each connection type.)

Start With the Chiller Plant

If HVAC is the largest load in the building, the chiller plant is the first place to measure. Electrical metering on the chiller supply gives you consumption and demand. Adding thermal measurement on the chilled-water loop gives you the ratio that actually describes efficiency — kW/TR, and from it COP.

That ratio is the one number a plant room cannot fake. It moves when tubes foul, when refrigerant is low, when a compressor stage is failing, and when pumps and towers are sequenced badly. Measured continuously against the commissioned figure, it turns chiller maintenance from a calendar exercise into a condition-led one.

For electrical-only monitoring the Titan meter is enough. For measured kW/TR and COP on a single device, use Titan Plus BTU, which combines Class 0.5S electrical metering with thermal metering designed to EN 1434 Class 2. If cooling is being billed to tenants rather than just monitored, that belongs on HVAC and chilled-water billing. You can model the numbers first with the chiller COP calculator.

Specification

What a consultant or specifier needs to write this into a tender.

ParameterSpecification
Accuracy classClass 0.5S active energy per IEC 62053-22 — tighter than the Class 1 typical on LT utility meters, so tenant bills hold up when disputed
Voltage / current48 V to 500 V AC, 3-phase 4-wire or 3-wire; CTs 100 A–1000 A (5 A secondary, Class 0.5S CTs)
Parameters measuredV, I, P, PF, f, kWh, kVARh, kVAh (import and export), maximum demand (kW, kVA, A)
Tariff registersTime-of-use / ToD registers configurable on-device; kVAh registers for apparent-energy tariffs
Power qualityIndividual voltage and current harmonics to the 31st order per phase, plus THD-V and THD-I — enough to catch distortion from VFDs, LED drivers, UPS and lift drives
BMS protocolsBACnet/IP over Ethernet or WiFi, BACnet MS/TP over RS485 — native, no gateway
Other protocolsModbus RTU (RS485), Modbus TCP (port 502), MQTT to any broker (TLS), HTTP/HTTPS and TCP/IP push
Protocol selectionRS485 runs one role at a time — Modbus RTU slave, Modbus RTU master or BACnet MS/TP, selected at commissioning; the Ethernet/WiFi side (Modbus TCP, MQTT, REST API, BACnet/IP) runs separately
Per-site infrastructureNone. WiFi and Ethernet built in — no energy-server PC, no data concentrator, no per-site licence
SustainabilityOn-device CO₂ using a configurable grid emission factor — Scope 2 data for BRSR, CSRD and GHG Protocol
MountingDIN rail, 94 × 89 × 69 mm — fits an existing riser sub-board or landlord panel without rework
Environment−25 °C to +70 °C, UL94 V-0 self-extinguishing enclosure, IP51 front face, EMC per IEC 61000-4 series
CommissioningTitan smartphone app over WiFi — no laptop, serial cable or proprietary software
Commercial terms₹8,500–₹18,300 per meter. No catalogue MOQ. Regular orders ship from stock; 200+ units 4 weeks from confirmed PO. Made in India

Frequently Asked Questions

Eight questions property and facility teams ask before specifying a building energy monitoring system.

A building energy monitoring system measures electricity consumption circuit by circuit across a building — chiller plant, AHUs, lifts, lighting risers, tenant supplies, car park — rather than taking a single reading at the utility meter. Each circuit gets a smart meter; the readings feed a dashboard that shows where consumption goes, when it is wasted, and what it costs. It is the measurement layer a BMS was never designed to provide: a BMS controls equipment, while an energy monitoring system measures it to metering-grade accuracy and keeps the history.
Because they do different jobs. A BMS is built to control HVAC, lighting and access — its outputs are setpoints and schedules. It usually polls meters every 15 minutes, stores the result in its historian, and rarely has metering-grade accuracy or power-quality data. An energy monitoring system measures every cycle at Class 0.5S, keeps the interval history, and is built around energy reporting, tenant chargeback and ESG disclosure. Most buildings run both: the BMS keeps control, the meters add the measurement layer beneath it. Titan feeds your existing BMS natively over BACnet or Modbus, so this is an addition rather than a replacement.
EnPI stands for Energy Performance Indicator — the metric an ISO 50001 energy management system tracks to show whether performance is actually improving. In a commercial building it is usually normalised rather than absolute: kWh per square metre, kWh per occupied room-night, or chiller kW/TR, so that a mild winter is not mistaken for an efficiency gain. EnPIs only work if the underlying measurement is granular enough to isolate the system being judged, which is why circuit-level metering rather than a single utility reading is the prerequisite.
In an HVAC context EMS is used two ways, which causes genuine confusion. Older HVAC literature uses it for an Energy Management System in the control sense — effectively a BMS that schedules and sets back plant. In energy and sustainability work it means an Energy Management System in the measurement and analytics sense: the layer that meters consumption, tracks EnPIs and produces reporting. Tech OVN builds the second kind, and it feeds the first over BACnet rather than replacing it.
Yes. Every Titan meter speaks BACnet/IP over Ethernet or WiFi and BACnet MS/TP over RS485, alongside Modbus RTU, Modbus TCP and MQTT — with no gateway, protocol converter or translation module in the data path. The RS485 port runs one role at a time — Modbus RTU slave, Modbus RTU master or BACnet MS/TP, selected at commissioning — while the Ethernet/WiFi side (Modbus TCP, MQTT, REST API, BACnet/IP) runs separately. That matters in a building because BACnet is the default protocol for Honeywell, Siemens Desigo, Johnson Metasys and Schneider EcoStruxure Building, and a gateway per riser is both a licence cost and a failure point.
A Class 0.5S meter per tenant supply gives you defensible interval data — Class 0.5S (IEC 62053-22) is a tighter accuracy class than the Class 1 typically used on LT utility meters, so the figure holds up when challenged. Recovering electricity costs from tenants is a lease matter, but resale of electricity is regulated under the Electricity Act 2003 and your state commission's (SERC) rules, so check how your state treats landlord-to-tenant recovery before you invoice. Time-of-use registers are configurable on-device if your tariff is time-of-day, and kVAh registers are available where the tariff bills on apparent energy. For cooling billed separately, thermal metering is a different measurement and is covered on the HVAC billing page.
₹8,500 to ₹18,300 per meter depending on variant, which is the cost per measurement point rather than per site. There is no minimum order quantity on catalogue meters — a pilot on the chiller plant alone is a valid order — and regular orders ship from stock (large quantities of 200+ units take 4 weeks from confirmed PO). There is no per-site energy server, gateway or software licence to buy, because WiFi and Ethernet are built into the meter.
Yes, and for a landlord or operator this is usually the main reason to do it. Each meter reaches the platform over WiFi or Ethernet on its own, so there is nothing per-site to roll out. Buildings appear in one portfolio view, which is what makes cross-building benchmarking possible — the same chiller model consuming 15% more at one property is a finding you cannot reach from single-building dashboards.
Not to assess it. Titan Audit uses split-core CTs that clamp around a live conductor, so a baseline survey can be taken across an occupied, running building with no shutdown. Permanently wired meters need a planned isolation on the circuit being metered, which normally folds into an existing maintenance window — the meter is DIN rail and 94 × 89 × 69 mm, so it fits an existing sub-board without panel rework.
Yes, for the Scope 2 electricity side. CO₂ is calculated on-device using a configurable grid emission factor, so the emissions figure is derived from measured kWh per circuit rather than back-calculated from invoices in a spreadsheet. That gives you consumption attributable to a building, a tenant or a system, which is the granularity disclosure frameworks increasingly expect.

Related Solutions & Products

The industrial counterpart, the people who run this, and the meters behind it.

Industrial Energy Monitoring

The factory and process-plant counterpart to this page — motor loads, production lines, compressed air and DG sets.

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Facility Management

One measurement layer serving the energy budget and the maintenance budget together, across a building or a portfolio.

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Energy Management System (EMS)

The platform above the meters — portfolio dashboards, ISO 50001 EnPI tracking and automated reporting.

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Titan Smart Energy Meter

Class 0.5S 3-phase DIN rail meter with WiFi, Ethernet and RS485, and native BACnet. The meter behind the monitoring.

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HVAC / Chilled-Water Billing

Billing tenants for cooling on measured thermal energy rather than apportioned floor area.

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Electricity Sub-Metering

Tenant and departmental sub-metering, CAM reconciliation and defensible chargeback.

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See where your building's energy actually goes

Talk to our team about metering a building or a portfolio — including which circuits to meter first and how it lands in your BMS.

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