How to Measure Thermal Energy

As energy costs and environmental concerns continue to rise, we count on our facility managers to take control of building/factory energy consumption. To reduce their companies’ carbon footprints, facility managers have begun implementing energy management programs to control their systems, optimize efficiency, and manage expenses.

But how are they doing it?

Let’s say you are trying to cool your facility. There are two steps to determining how much energy is consumed in the process.

First, you need to know how your building is cooled.

In this scenario, your facility is cooled by pumping chilled water throughout the building on a loop.  To determine energy consumption, we can compare the flow and temperature of the water when it first enters the building, to the flow and temperature of the water when it returns.

This should give you some insight on how much energy you are consuming and what exactly it is costing you.

But, let’s say you have multiple office spaces in your building. How do you know how much energy each office is consuming? This is where sub-metering comes into play.

Sub-metering can help you pinpoint which offices consume the most energy, so you can allocate utility charges according to their consumption. To do so, you would need to place a flowmeter and temperature sensor in every office and take the same measurements as mentioned above.

Once you know the specific offices’ thermal energy measurements, you can use the data to control the distribution of chilled and hot water to reduce the overall energy consumption of the building.

In this scenario, either a magnetic or clamp-on flowmeter would be appropriate, as they are both ideal for chilled water (CHW) and heated water (HW) applications.

Clamp-on flow measurement technology offers a solution for flow measurement that is both highly accurate and cost efficient.

The Siemens SITRANS FUS clamp-on ultrasonic flowmeters, unlike conventional flowmeters, are non-intrusive, meaning the sensors are mounted externally. This design avoids having to shut down the process to cut into the pipe — simplifying installation and eliminating downtime.

Learn more about Siemens SITRANS FUS clamp-on ultrasonic flowmeters


Lesman Instrument Company is the authorized Siemens representative in Illinois, Indiana, Missouri, Paducah KY, Wisconsin, and Michigan’s Upper Peninsula. If you are located outside that area, you can find your local sales office or get technical assistance by calling 800-365-8766.


, , , , , , , , , , , , , ,

  1. Leave a comment

Care to Comment?

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: