Emergent Metering
Book a Demo

Collection

BTU Meters & Thermal Energy Metering

A BTU meter measures thermal energy — not volume. It pairs a flow meter with matched supply and return temperature sensors, and computes energy delivered from flow rate multiplied by the temperature differential. That is what you need to bill a tenant for chilled water, allocate central plant costs, or verify that a heat exchanger is performing.

We supply ultrasonic and insertion BTU meters for chilled water, hot water, condenser water and glycol systems, including the EES-301 ultrasonic BTU meter, pre-configured for your specific application — pipe size, fluid type, flow range and temperature range set before it ships, so it arrives ready to commission.

How to specify a BTU meter

You need five pieces of information, and getting any of them wrong means the meter reads inaccurately:

  • Pipe size and material — determines the meter body or clamp-on transducer spacing
  • Fluid — water, glycol mix (and what percentage), or another heat transfer fluid. Glycol changes the specific heat calculation.
  • Flow range — minimum and maximum, not just design flow. Meters lose accuracy at the bottom of their range.
  • Temperature range and expected delta-T — a small delta-T requires matched, higher-accuracy RTD pairs
  • Output — pulse, Modbus, BACnet or M-Bus, depending on where the data goes

Send us those five and we will configure it. See meter selection help for BTU metering.

Common applications

Tenant thermal billing. Multi-tenant buildings on a central chilled water plant need per-tenant BTU metering to allocate cost fairly. See meter requirements for tenant billing.

Central plant efficiency. Metering thermal output against electrical input gives you real plant efficiency (kW/ton), which is the only way to know whether a chiller is degrading.

Energy code compliance. IECC 2024 C405.13.7 extends submetering requirements to non-electrical end uses, including thermal. What C405.13.7 requires

LEED and measurement & verification. BTU metering is how you evidence thermal savings in an M&V plan.

Showing 1–2 of 2 products

EES-401 Ultrasonic Energy (BTU) Meter (High Precision)

Emergent Energy Solutions

EES-401 Ultrasonic Energy (BTU) Meter (High Precision)

From $3,450.00

In stock
EES-301 Ultrasonic Energy (BTU) Meter

Emergent Energy Solutions

EES-301 Ultrasonic Energy (BTU) Meter

From $2,195.00

In stock

BTU Meters & Thermal Energy Metering — FAQ

Common questions about this category.

What is a BTU meter?
A BTU meter measures thermal energy delivered by a hydronic system. It combines a flow meter with matched supply and return temperature sensors and calculates energy as flow rate multiplied by the temperature difference and the fluid's specific heat. It reports in BTU, ton-hours or kWh rather than gallons.
What is the difference between a BTU meter and a water meter?
A water meter measures volume, meaning how many gallons passed through the pipe. A BTU meter measures energy, meaning how much heating or cooling that water delivered. Two tenants can consume identical water volume and very different amounts of thermal energy depending on their temperature differential, which is why chilled water billing requires a BTU meter rather than a water meter.
How accurate are ultrasonic BTU meters?
Accuracy depends on the flow measurement, the temperature sensor pair and the installation. Matched RTD pairs are essential, because unmatched sensors introduce error directly into the energy calculation and that error grows as the temperature differential shrinks. Straight pipe runs upstream and downstream of the flow element also affect accuracy.
Can a BTU meter be installed without cutting the pipe?
Yes. Clamp-on ultrasonic transducers mount on the outside of the pipe and require no shutdown or pipe penetration for the flow element. Temperature sensors may still require thermowells depending on the installation.
Do I need a BTU meter for chilled water tenant billing?
Yes, if you are billing for cooling delivered rather than water consumed. Volume-only billing charges a tenant with a large temperature differential the same as one with a small differential, even though the first consumed far more plant energy.
What information is needed to configure a BTU meter?
Pipe size and material, fluid type including glycol percentage, minimum and maximum flow rate, operating temperature range and expected temperature differential, and the required output protocol such as pulse, Modbus, BACnet or M-Bus.

Related guidance

Selection guides, code-compliance reading, and field results for this product line.

Ready to put energy data to work?

Order sensors, bridges, and PowerRadar subscriptions from our store — or talk to a CEM-certified engineer about your project.

Shop SensorsTalk to an Engineer215-645-7141