The 22PE-5XUDNH is a Belimo thermal energy meter (BTU meter) that measures water or water-glycol flow plus supply and return temperatures, then calculates and reports the actual thermal energy transferred by a heating or cooling circuit. Designed for plant submetering, tenant billing, central plant efficiency tracking, and ASHRAE 90.1 compliance reporting on chilled water, hot water, and glycol systems. This 5XU extended variant fits a DN20 (3/4") pipe with a nominal flow rate of 11.0 GPM (22.0 GPM peak, 0.11 GPM minimum) at 1.7 psi pressure drop. Measurement uses ultrasonic flow sensing (no moving parts, no wear) combined with two Pt1000 Class B temperature sensors (one integrated, one external T1 on a 3 m cable for the return-side measurement). The unit includes automatic temperature and glycol compensation, NIST/SI/BIPM-traceable calibration, and comprehensive BMS connectivity via BACnet/IP, BACnet MS/TP, Modbus TCP, Modbus RTU, and MP-Bus Ñ plus an integrated web server for browser-based configuration and Belimo Cloud connectivity for IoT remote metering and tenant billing workflows. Adds a humidistat-controlled 21 W heater for chilled-water installs in humid spaces.
Thermal energy submetering and billing in commercial buildings: central plant supply/return BTU measurement for efficiency tracking, individual tenant chilled-water and hot-water billing (recovery from base building), campus district heating/cooling plant monitoring, LEED EAc5 measurement and verification, ASHRAE 90.1 mandatory submetering for systems over 100 tons, and any installation where actual delivered thermal energy needs to be measured rather than estimated from flow alone. For the base 5U variant at the same flow rating without the heater option (lower price, for indoor mechanical rooms where condensation is not a concern), see the 22PE-5U family.
The 22PE-5XUDNH can connect to the Belimo Cloud for remote IoT metering and tenant billing Ñ read energy totals, flow rates, supply/return temperatures, and alarm states from anywhere via the cloud dashboard or API. For on-site configuration, an integrated web server lets you connect directly to the meter via Ethernet and configure all parameters from any browser Ñ no proprietary software, no commissioning laptop with vendor tools. NFC + Belimo Assistant 2 mobile app provides a third configuration path for field tech walkthroughs.
Calibration chain documented back to NIST, SI, and BIPM Ñ defensible for billing accuracy, regulatory compliance, and LEED/ASHRAE 90.1 submetering compliance. Meets EN 1434 Class 2 at 59-248¡F, carries IEC/EN 60730-1 and 60730-2-15 certification.
This variant includes an aluminum-profile heater with a humidistat sensor that activates the 21 W heating element when ambient humidity rises above the trip point. Designed for chilled-water installations in humid mechanical rooms where the cold meter electronics could see condensation on the housing or internal components. Normally-closed contact, max 2.5 A inrush current. Aluminum profile (anodized) housing with thermobimetal sensor element. Choose this variant when the install location is conditioned but humid (e.g., basement plant rooms, coastal climates).
Key Features
Bidirectional ultrasonic transit-time measurement across a 3/4" flow section Ñ no impeller, no turbine, no obstruction in the flow path. No bearing wear, no calibration drift from mechanical components, no pressure drop beyond the 1.7 psi geometry loss at nominal flow. Maintenance-free for the lifetime of the meter.
One Pt1000 sensor (T2) integrated into the flow body for the meter-side fluid temperature; one Pt1000 sensor (T1) on a 3 m cable for installation on the opposite side of the heating/cooling element. Inseparably connected to the logic module Ñ paired and calibrated together at the factory. Class B accuracy (±0.35¡C @ 10¡C); differential accuracy ±0.22 K @ 10K ÆT.
The meter automatically compensates BTU calculations for fluid temperature and for glycol concentration up to 60% by volume. Configure the glycol mix percentage in commissioning (via NFC, web server, or BMS) and the meter handles the density and specific-heat corrections internally Ñ no external math required for billing-grade accuracy.
Universal BMS connectivity over a single device: BACnet/IP and Modbus TCP over Ethernet; BACnet MS/TP and Modbus RTU over RS-485; Belimo MP-Bus for daisy-chain integration with Belimo actuators. M-Bus support via the G-22PEM-A01 converter accessory. Configurable device instance and MAC; full BACnet object list and Modbus register map in the included interface description PDFs.
Powered from a standard IEEE 802.3af/at Type 1 Class 3 PoE switch (DC 37-57V, 11W PD13W) Ñ single Cat 5e/6 cable carries power and BACnet/IP traffic. Eliminates the need for a 24V transformer at the meter, reduces wiring runs, and centralizes the power budget in the network closet where battery backup (UPS-fed PoE switch) is typically already in place.
Plug a laptop into the meter's RJ45 jack and open a browser Ñ the meter hosts a complete configuration interface natively. No proprietary commissioning software, no vendor-specific dongles, no driver installs. View live flow / temperature / energy values, change setpoints, update firmware, and export logs from any device with a browser. Critical for sites where IT restricts software installs.
Tap an NFC-capable phone with the free Belimo Assistant 2 app against the meter to read live values or push configuration changes Ñ no power required for the tap, useful for pre-commissioning before the meter is wired and energized.
Connect the meter to Belimo Cloud for remote energy/flow trending, alarm notification, multi-site rollups, and tenant billing data export. Cloud subscription separate; the cloud-ready hardware is included in the meter. Useful for portfolios managing dozens or hundreds of submeters from a central operations team.
Technical Specifications
| Specification | Detail |
|---|---|
| Type | Thermal Energy Meter (BTU meter) Ñ flow + dual temperature _ energy calculation |
| Pipe Size | DN20 (3/4") |
| Pipe Connection | External thread per ISO 228-1 |
| Pressure Rating | PN 25 (360 psi body pressure rating) |
| Nominal Flow (qp) | 11.0 GPM |
| Highest Flow (qs) | 22.0 GPM (auto-limit at 2.5 _ qp) |
| Lowest Flow (qi) | 0.11 GPM |
| Dynamic Range (qi:qp) | 1:100 |
| Pressure Drop at qp | 1.7 psi |
| Flow Measurement Principle | Ultrasonic transit-time (no moving parts) |
| Flow Accuracy | ±2% of 20-100% qp at 68¡F / 0% glycol (EN 1434 Class 2 at 59-248¡F) |
| Temperature Sensors | 2x Pt1000 EN 60751 Class B, 2-wire (T1 external 3 m cable, T2 integrated, inseparably connected) |
| Temperature Accuracy | ±0.35¡C @ 10¡C; ±0.6¡C @ 60¡C (absolute) |
| Differential Temperature Accuracy | ±0.22 K @ 10K ÆT; ±0.32 K @ 20K ÆT |
| Calibration Traceability | NIST, SI, and BIPM-traceable |
| Compatible Fluid | Chilled or hot water, water-glycol mixture up to 60% by volume (closed-loop only; open loop and steam not permitted) |
| Voltage Output | 1x 0-10V / 0.5-10V / 2-10V (selectable) |
| Communication | BACnet/IP, BACnet MS/TP, Modbus TCP, Modbus RTU, MP-Bus (M-Bus via G-22PEM-A01 converter accessory) |
| MP-Bus Capacity | Up to 8 (16) devices per bus segment |
| Configuration | NFC (Belimo Assistant 2 app), integrated web server (browser via Ethernet), BMS over BACnet/Modbus |
| Belimo Cloud | Compatible (subscription separate) |
| Nominal Voltage | AC/DC 24 V |
| Voltage Frequency | 50/60 Hz |
| Voltage Range | AC 19.2-28.8 V; DC 21.6-28.8 V |
| Power Consumption | 3 VA AC / 1.5 W DC / 2.2 W PoE |
| Power over Ethernet (PoE) | DC 37-57 V; IEEE 802.3af/at Type 1 Class 3; 11 W PD13W |
| Annual Energy Consumption | 13.2 kWh (external supply) |
| Supply Cable | 3 ft (1 m), 6x 0.75 mm_ |
| Ethernet Connection | RJ45 socket |
| Servicing | Maintenance-free |
| Inlet Length Required | ³0 _ DN per EN 1434-4:2022 (no straight-pipe requirement) |
| Protection Class | IEC/EN III, PELV (Protective Extra-Low Voltage) |
| Logic Module IP | IP54 (with A-22PEM-A04 grommet accessory) |
| Sensor Module IP | IP65 |
| NEMA Rating | NEMA 2 |
| Certification | IEC/EN 60730-1:11, IEC/EN 60730-2-15:10, NIST / SI / BIPM-traceable, ISO 9001 |
| Pressure Equipment Directive | CE per 2014/68/EU |
| EMC | CE per 2014/30/EU |
| Ambient Temperature | -22 to 122¡F (-30 to 50¡C) |
| Fluid Temperature | -4 to 250¡F (-20 to 120¡C); frost protection required below 36¡F (2¡C) |
| Storage Temperature | -40 to 176¡F (-40 to 80¡C) |
| Ambient Humidity | Max. 95% RH, non-condensing |
| Pollution Degree | 3 |
| Cable Material | PVC |
| Fluid-Wetted Parts | Brass nickel-plated, brass, stainless steel, PEEK, EPDM |
| Heater Type | Humidistat-controlled, 21 W (NC contact, 2.5 A inrush, aluminum anodized w/ thermobimetal sensor) |
| Manufacturer | Belimo |
| Manufacturer Part Number | 22PE-5XUDNH |
| Warranty | 5-year factory warranty |
What's In the Box
- 22PE-5XUDNH thermal energy meter assembly: logic module + flow sensor module (3/4" DN20)
- External temperature sensor T1 with 3 m (10 ft) factory-paired cable
- Integrated temperature sensor T2 (inside flow body, factory-installed)
- 3 ft (1 m) supply cable, 6x 0.75 mm_ (terminations on logic module)
- Internal humidistat heater (21 W, factory-installed)
- Mounting hardware and seals appropriate to the flow body
Sold separately: A-22PEM-A04 grommet (required for IP54), G-22PEM-A01 (M-Bus converter), Belimo Cloud subscription.
Documentation
Frequently Asked Questions
What does the 22PE-5XUDNH measure?
It measures three things and uses them to calculate a fourth: (1) volumetric flow via ultrasonic transit-time on a DN20 (3/4") flow body (11.0 GPM nominal, 0.11-22.0 GPM operating range), (2) supply temperature via an external Pt1000 sensor (T1) on a 3 m cable, (3) return temperature via an integrated Pt1000 sensor (T2). From these it calculates the thermal energy transferred by the circuit Ñ BTU on the imperial side, kWh on the metric side. All four values are available to the BMS via BACnet, Modbus, MP-Bus, the integrated web server, or Belimo Cloud.
What's the difference between the 5U and 5XU variants?
Both families share the same flow sensing, temperature sensing, accuracy, communication, and configuration capabilities. The 5XU adds optional condensation-prevention heaters (humidistat or thermostat-controlled, 21W) for installations where cold-water meter electronics could see condensation (humid mechanical rooms, unconditioned plant rooms, outdoor-adjacent installs). Choose the 5U for standard indoor conditioned mechanical rooms; choose the 5XU when condensation is a concern. The 5XU also explicitly supports two flow ratings at 2" (N = standard 66 GPM, K = high-flow 100 GPM) as separate SKUs.
How does the BTU calculation handle glycol mixtures?
Configure the glycol percentage (0-60% by volume) during commissioning via NFC, the web server, or your BMS. The meter applies the correct density and specific-heat corrections internally to the BTU calculation Ñ no external math, no constants to enter into the BMS, no calibration tables. The compensation is automatic across the full fluid temperature range. Open-loop systems and steam applications are not supported.
What's required for PoE operation?
An IEEE 802.3af/at Type 1 Class 3 PoE switch capable of delivering 11W (PD13W) at DC 37-57V. Standard Cat 5e or Cat 6 cable. Shielded cables are recommended for the PoE supply per Belimo guidance. With PoE, no 24V transformer is needed at the meter Ñ a single Cat 5e cable carries power and BACnet/IP traffic. Useful when the meter location is far from the nearest 24V control transformer or when you want to centralize the power budget in a UPS-backed network closet.
How accurate is it for billing applications?
Flow: ±2% of reading from 20-100% qp at standard conditions, EN 1434 Class 2 accuracy across 59-248¡F fluid temperature. Temperature: ±0.35¡C absolute at 10¡C; differential ±0.22 K at 10K ÆT (which is what matters for the BTU calculation). Calibration is NIST/SI/BIPM-traceable with documented traceability chain Ñ defensible for billing disputes, LEED EAc5 measurement and verification, and ASHRAE 90.1 mandatory submetering compliance.
- Sensor Type:
- Thermal Energy Meter (BTU Meter)
- Measurement Principle:
- Ultrasonic flow + dual Pt1000 temperature
- Pipe Size:
- DN20 (3/4)"
- Nominal Flow (qp):
- 11.0 GPM
- Highest Flow (qs):
- 22.0 GPM
- Lowest Flow (qi):
- 0.11 GPM
- Pressure Drop at qp:
- 1.7 psi
- Pressure Rating:
- PN 25 (360 psi)
- Pipe Connection:
- External thread per ISO 228-1
- Flow Accuracy:
- EN 1434 Class 2 (±2% of qp)
- Temperature Element:
- 2x Pt1000 EN 60751 Class B
- Temperature Accuracy:
- ±0.35 C at 10 C
- Differential Temp Accuracy:
- ±0.22 K at 10K dT
- Glycol Compensation:
- Automatic, 0-60% by volume
- Calibration Traceability:
- NIST / SI / BIPM-Traceable
- Communication:
- BACnet/IP + BACnet MS/TP + Modbus TCP + Modbus RTU + MP-Bus
- M-Bus Support:
- Via G-22PEM-A01 converter (separate)
- Analog Output:
- 1x 0-10V / 0.5-10V / 2-10V (selectable)
- Configuration:
- NFC + Web Server + BMS
- Belimo Cloud:
- Compatible (subscription separate)
- Power:
- 24 VAC/VDC or PoE (IEEE 802.3af/at Type 1 Class 3)
- PoE Power:
- 11 W PD13W
- Ethernet:
- RJ45
- Sub-Family:
- 5XU Extended
- Flow Variant:
- Standard
- Condensation Prevention:
- Humidistat heater (21W, NC contact, 2.5A inrush)
- Heater Activation:
- Humidity-sensing
- Logic Module Enclosure:
- IP54 (with A-22PEM-A04 grommet)
- Sensor Module Enclosure:
- IP65
- NEMA Rating:
- NEMA 2
- Fluid Temperature Range:
- -4 to 250 F (-20 to 120 C)
- Ambient Temperature Range:
- -22 to 122 F (-30 to 50 C)
- Compatible Fluid:
- Water / Water-Glycol (closed loop only)
- Maintenance:
- Maintenance-free (no moving parts)
- Inlet Length Required:
- 0 x DN (no straight pipe required)
