Dwyer Instruments TUF-250-MD | Tenant ultrasonic BTU flowmeter | DN25 pipe size and 3.5 m3/h permanent flow rate with Modbus® communication

The Dwyer TUF-250-MD is a tenant ultrasonic BTU flowmeter designed for DN25 piping and a 3.5 m³/h permanent flow rate. It combines ultrasonic flow measurement, temperature sensing and energy calculation in one compact unit, with Modbus® RTU communication for building management and utility billing systems.

Part Number: TUF-250-MD

Genuine Dwyer stock at General Tech Services LLC, UAE, with free UAE-wide shipping. Request a quote in under a minute — call +971 6 5436933.

Product Overview

The Dwyer Series TUF Ultrasonic Energy Meter provides accurate and stable measurement of heating and cooling energy consumption in clean, compatible liquids. The TUF-250-MD is the DN25 version, rated for a 3.5 m³/h permanent flow rate, and combines a flowmeter, temperature sensors and energy calculator in a single compact device.

This integrated design makes the TUF-250-MD suitable for tenant-level heat metering, utility billing and energy monitoring in applications including chillers, boilers, radiators, fan coil units and individual apartment or tenant piping.

The ultrasonic measurement principle uses no moving parts, helping reduce maintenance requirements compared with mechanical BTU meters. An integrated 8-digit LCD provides a local readout of temperature, flow rate and energy consumption directly at the meter.

The TUF-250-MD provides Modbus® RTU serial communication for integration with compatible building management systems, energy monitoring platforms and utility billing systems. This allows measured flow, temperature and energy data to be transferred to connected systems.

The meter features a plastic housing with brass and 316L stainless steel wetted parts and an IP65 enclosure rating. It supports horizontal or vertical installation. On horizontal pipe runs, the installation position should be at least 45° from horizontal to help prevent debris accumulation.

The DN25 model uses a threaded G1B connection within the DN15–DN40 connection range. The unit operates from a 24 Vac/Vdc supply, with an optional user-installed 3.6V ER26500 lithium battery for backup during power interruptions.

For the same DN25 flowmeter configuration with a different communication protocol, the TUF-250-BN variant uses BACnet MSTP instead of Modbus® RTU.

Key Benefits

• Combines ultrasonic flow measurement, temperature sensing and energy calculation in one compact meter
• Designed for DN25 piping with a 3.5 m³/h permanent rated flow
• No moving parts, helping reduce mechanical wear and maintenance requirements
• Integrated 8-digit LCD for local temperature, flow and energy readings
• Modbus® RTU communication for BMS and utility billing integration
• IP65-rated plastic housing
• Brass and 316L stainless steel wetted components
• Optional lithium battery backup for the display and stored readings during power interruption
• Suitable for tenant-level heating and cooling energy metering
• Free UAE-wide shipping on genuine Dwyer stock
• Call +971 6 5436933 for pricing and stock availability

Who This Product Is Best For

• Landlords and property managers requiring tenant-level heating or cooling BTU billing
• Building owners monitoring chillers, boilers, radiators or fan coil units
• BMS integrators using Modbus for utility and energy sub-metering
• Facilities teams managing heating and cooling energy consumption
• Commercial and residential developments requiring individual tenant energy measurement

How to Specify & Commission It

1. Confirm that the TUF-250-MD's DN25 pipe size and 3.5 m³/h permanent rated flow are suitable for the piping system and application.
2. Install the meter using the threaded G1B connection, following the manufacturer's installation requirements. On horizontal pipe runs, maintain an installation position at least 45° from horizontal.
3. Connect the 24 Vac/Vdc power supply and install the optional 3.6V ER26500 lithium battery if power-loss backup is required.
4. Connect the Modbus® RTU output to the BMS or billing system and configure the required communication parameters.
5. Verify the flow, temperature and energy readings on the local 8-digit LCD before commissioning and handover.

Frequently Asked Questions

What pipe size and flow rate is the TUF-250-MD designed for?

The TUF-250-MD is designed for DN25 piping with a 3.5 m³/h permanent rated flow rate.

What communication protocol does the TUF-250-MD use?

This model uses Modbus® RTU serial communication for integration with compatible BMS, monitoring and utility billing systems.

What accuracy class does the Series TUF provide?

The Series TUF provides BTU accuracy Class 2 according to EN1434/CJ128. Flow accuracy is ±(2+(0.02 Qp/Q))%, while temperature accuracy is ±0.1°C (±0.18°F).

What is the maximum operating pressure?

The maximum operating pressure is 232 psi (16 bar).

What are the ambient and process temperature ranges?

The ambient temperature range is 41 to 131°F (5 to 55°C), while the process temperature range is 36 to 203°F (2 to 95°C).

Does the TUF-250-MD require external power?

The meter operates from a 24 Vac/Vdc supply. An optional user-supplied 3.6V ER26500 lithium battery can provide backup for the display and stored readings during a power interruption.

What is the difference between the TUF-250-MD and TUF-250-BN?

Both models use the same DN25 flowmeter configuration and rated flow specification. The main difference is the communication protocol: the TUF-250-MD uses Modbus® RTU, while the TUF-250-BN uses BACnet MSTP.

Can the TUF-250-MD be installed vertically?

Yes. The meter supports horizontal or vertical installation. For horizontal pipe runs, the installation should be at least 45° from horizontal according to the stated installation requirement.

Is genuine Dwyer stock available with UAE shipping?

Yes. Genuine Dwyer stock with free UAE-wide shipping is available from General Tech Services LLC. Call +971 6 5436933 for current pricing and availability.

Request a Quote Today

For pricing, availability or to place an order for the Dwyer TUF-250-MD, contact General Tech Services LLC.

Call +971 6 5436933 | www.generaltechshop.ae