Data centers are designed around reliability. Cooling systems must continue operating as servers, networking equipment, and computing workloads generate heat around the clock. This makes modifications to existing cooling infrastructure more challenging than they may appear.

Adding a traditional inline flowmeter to an existing cooling-water line may require the system to be shut down, drained, cut, and modified. For facilities where cooling interruption is undesirable, clamp-on ultrasonic flow measurement can provide a practical alternative.

Smart Measurement’s ALSONIC-FX2 is a fixed clamp-on ultrasonic flowmeter designed for permanent non-intrusive measurement in appropriate liquid applications. The application note specifically identifies existing data-center chilled-water piping and cooling-system retrofit projects as potential applications.

Why Data Center Cooling Retrofits Are Challenging

New data centers can incorporate flow instrumentation during initial construction. Existing facilities are different.

A retrofit project may involve:

• Operating chilled-water systems
• Existing pipework
• Limited shutdown windows
• Critical cooling loads
• Difficult access
• Multiple cooling zones
• Large pipe sizes

Cutting into a cooling pipe can introduce additional engineering work and potentially disrupt operations.

For this reason, facility engineers may look for non-invasive flow measurement technologies.

What Is a Clamp-On Ultrasonic Flow Meter?

A clamp-on ultrasonic flowmeter uses transducers mounted externally on the outside of the pipe.

The transducers transmit and receive ultrasonic signals through the moving liquid. Transit-time measurement evaluates the difference between upstream and downstream signal travel times to determine fluid velocity and calculate flow.

Because the transducers are mounted externally, the measurement equipment does not require the same type of pipe penetration as an inline meter.

Smart Measurement’s ALSONIC-FX2 documentation describes this transit-time principle and its clamp-on configuration.

ALSONIC-FX2 for Existing Cooling-Water Piping

The ALSONIC-FX2 fixed clamp-on ultrasonic flowmeter is positioned in the Smart Measurement application note as a permanent non-intrusive retrofit solution.

It can be considered for:

• Existing data-center chilled-water piping
• Cooling-system retrofit projects
• Chiller monitoring
• Heat-exchanger monitoring
• Existing CRAH/AHU circuits
• Permanent monitoring where shutdown is undesirable

The application notes state that installation can be performed without cutting into the cooling-water pipe or interrupting process flow.

This characteristic can be particularly valuable in operating data centers.

Advantages of Non-Intrusive Flow Measurement

A clamp-on ultrasonic flowmeter can offer several practical advantages for retrofit projects.

No Pipe Cutting

The external transducer arrangement means engineers do not need to install the measurement device by cutting a section of the existing pipe for an inline sensor.

Reduced Process Disruption

Because measurement can be performed externally, a suitable clamp-on installation can avoid interruption of cooling-water circulation.

Retrofit Flexibility

Existing pipes can be monitored without redesigning the entire cooling-water system.

Smart Measurement also describes non-intrusive ultrasonic flow measurement as a cost-effective retrofit approach in its broader applications information.

Where Can Clamp-On Ultrasonic Flowmeters Be Used?

In a data center, flow measurement may be required at multiple points.

Potential locations include:

• Chiller circuits
• CRAH cooling branches
• AHU cooling circuits
• Existing chilled-water piping
• Heat-exchanger circuits
• Cooling zones
• Data-hall distribution
• Other suitable liquid-cooling circuits

The correct installation depends on pipe configuration and application conditions.

Clamp-On Measurement for Chiller Monitoring

Chillers are central components of many cooling infrastructures.

Monitoring water flow through chiller circuits can help engineers understand whether the hydraulic side of the system is operating as expected.

If flow changes unexpectedly, the measurement data can contribute to troubleshooting.

Potential causes may include pump issues, valve positions, restrictions, or hydraulic imbalance. The Smart Measurement application note identifies several of these conditions as potential causes of unexpected flow reductions.

Using Portable Ultrasonic Measurement Before Permanent Installation

A useful approach during a retrofit project can be to perform temporary measurements before deciding on permanent instrumentation.

The ALSONIC-PL portable ultrasonic flowmeter is designed for portable measurement and can be used for applications including commissioning, balancing, chiller performance testing, pump studies, troubleshooting, and energy audits.

This allows engineers to investigate an existing cooling system before committing to permanent measurement points.

The current Smart Measurement product page also identifies ALSONIC PL as a portable clamp-on ultrasonic solution for water, HVAC, and maintenance applications.

Clamp-On Ultrasonic Flow Measurement and Cooling Optimization

Installing a flowmeter is not an end in itself. The objective is to obtain useful information.

Flow measurements can support:

• Cooling-system balancing
• Pump evaluation
• Chiller performance studies
• Cooling-zone comparison
• Troubleshooting
• Energy analysis
• Permanent monitoring

For example, engineers may compare flow between cooling zones to identify differences in hydraulic distribution.

The application note specifically identifies comparing cooling zones and verifying permanently installed flowmeters as applications for portable measurement.

Flow Measurement Without Cooling Shutdown

One of the most important considerations in an operational data center is maintaining cooling availability.

A shutdown may not always be practical simply to install an additional measurement device.

This is where non-intrusive ultrasonic flowmeters can be valuable.

The ALSONIC-FX2 uses externally mounted transducers, allowing permanent flow measurement without cutting into the pipe or interrupting flow.

For data center operators, this can simplify the process of adding measurement capability to an existing cooling infrastructure.

Data center cooling retrofits require careful consideration because cooling systems support critical computing infrastructure. Traditional inline installation may require pipe modifications and service interruptions that are undesirable in an operating facility.

Clamp-on ultrasonic flowmeters provide an alternative approach for suitable cooling-water applications.

Smart Measurement’s ALSONIC-FX2 provides permanent non-intrusive measurement, while ALSONIC-PL can support portable testing, commissioning, balancing, troubleshooting, and energy studies.

For facility engineers looking to improve data center cooling monitoring without extensive pipe modifications, non-intrusive ultrasonic technology can be an effective measurement approach.