How This University Improved Sustainability With Electromagnetic Meters

One Midwestern university sought flow measurement solutions as part of a larger Leadership in Energy and Environmental Design (LEED) project. The goal was two-fold: perform an energy audit and then identify how to decrease energy consumption and assure accurate cost allocation in campus buildings.

Resolving a steam challenge

This university is located on an urban campus spread across 365 hectares and home to nearly 10,500 students. To maintain comfort and operations within its facilities, the university has a central plant that produces resources which are then sold to each campus building for heating and cooling. Accurate cost allocation is critical to ensure buildings are paying for the resources they use, no more and no less.

Previously, the university produced steam and was using vortex and differential pressure meters to monitor consumption. While suitable for this application, these meters are often higher maintenance, more expensive and less accurate than other flow measurement tools. For example, it was difficult to achieve low flow measurement in the summertime when facilities were less populated due to the limited flow range of these meters.

Because of these challenges, facilities managers sought out a new solution to accurately account for consumption year-round, which included converting steam production into condensate return measurement. They selected this option because condensate values can be accounted for much more accurately as it’s returned to the central plant versus trying to capture steam with inadequate meters.

Implementing a suitable solution

To better manage campus energy usage, facilities managers specified ModMAG^® M2000 Electromagnetic flow meters because of their high accuracy and low pressure drop. At least one meter was installed in each building on campus, totaling more than 50 flow meters. This included multiple in the central plant to support accurate measurement for incoming and outgoing condensate loads. 

Facilities managers were eager to get the solution up and running to start accurately measuring energy usage. This project was completed during a roughly six-week period over summer break to avoid interruption to university classes.

Discovering more benefits of electromagnetic meters

An added point of concern in measuring condensate is water conductivity. If condensate has a low level of conductivity, it can cause incorrect meter reads.

Because this university uses heat exchanger-style humidification, it was critical that facilities managers monitor heat exchangers closely. In the event the heat exchanger fails and cracks, a surge of high conductivity tap water is drawn into the steam line and discharged through the electromagnetic meter as condensate.

Before the mag meters were installed, facilities managers had to physically inspect the heat exchanger in each building until they found a fault, which often took a week or more to discover. Now, the team can identify which building’s heat exchanger has failed almost instantly because they use the Empty Pipe Calibration value to correlate to the conductivity of the water. This information is pulled over Modbus—a serial communication protocol—to ensure conductivity rates stay at or around 25 micro siemens, which is the industry standard.

Having the ability to identify where the failed heat exchanger is located is a significant improvement considering leaks were previously found only when the leak was large enough to increase the conductivity of all steam condensate return lines coming into the main plant.

Improving visibility across the campus

As a result of this electromagnetic meter deployment, the campus now has near real-time visibility within every building, which is sourced on its website. Facilities managers can see energy usage within each building to monitor use, identify potential problems before they escalate and make conscious efforts to decrease consumption across campus.

The university has also been working to educate its students, teachers, faculty, etc., on the importance of energy-conscious actions to establish responsible behaviors.