UNC Chapel Hill: Open Systems Temperature-Control
Affinity Energy worked with local university to provide an “open systems” alternative for critical temperature-controlled research rooms.
The University of North Carolina at Chapel Hill
The University of North Carolina at Chapel Hill ranks #8 in research activity among both public and private universities in the United States, and spends nearly 1 billion dollars in annual research expenditures.
A large part of that research is done in 1,000 scientific chambers, cold rooms, warm rooms, and freezers scattered throughout campus. Some store critical products in the millions of dollars and others provide the base for performing critical research to life science. The room temperature must be very accurate, within half a degree, due to the controlled experiments conducted in these rooms.
Not only is the HMI Affinity Energy designed for us a lot easier to navigate, having the capability to plug into the controller to conduct maintenance and troubleshooting is a real home run for our techs.
Mark Obenshain, Assistant Director – HVAC Operations, UNC Chapel Hill
Because many of the rooms are more than 20 years old, it became increasingly difficult to find controller parts. Eventually, the university couldn’t find a supplier to repair a malfunctioning temperature controller in one of their environmental chambers. Because all the rooms were installed in a similar timeframe, it was only a matter of time before maintainability became a campus-wide issue.
In addition, researchers utilizing the rooms needed to be able to view the temperature real time, and required tighter humidity and temperature controls…both impossible in the old system.
After contacting their original controls provider, they learned the price to upgrade the proprietary system was out of reach on a public university budget.
UNC Chapel Hill sought a more affordable, flexible, downward compatible solution.
After speaking with many integrators who heavily guarded their proprietary programming technology, UNC Chapel Hill decided to work with Affinity Energy after hearing of the company’s reputation with open-system PLC integration in critical systems.
Affinity Energy designed a customizable, universal panel prototype that would work to regulate temperature in any and all of UNC Chapel Hill’s rooms, no matter which controller they were currently using.
After extensive hardware and controller research, UNC Chapel Hill specified Automation Direct, a manufacturer of non-proprietary control solutions, as the basis of design for the majority of the control components. Because Automation Direct software is open, the university wouldn’t have to be held hostage to proprietary software or a particular systems integrator if they wanted to make adjustments or completely overhaul the system in the future.
New Visibility & Control Capabilities
Previously, researchers had only rudimentary indication of a room’s temperature and in case of failure, no indication, until opening a cold room door and feeling a warm blast of air. The old controller may not be consistent with the temperature fluctuating between thresholds.
Affinity Energy engineered a temperature control system integrating Automation Direct’s Do-more PLC that enhanced researchers’ ability to have smoother, more accurate control. The installation of a color and touch screen C-more HMI offered new and detailed data points like temperature, humidity, liquid line and hot gas valve status, and defrost cycle activity.
To alert researchers and maintenance personnel of out-of-tolerance temperature values, Affinity Energy included alarming functionality. In addition to an alarm message displayed on the HMI, an audible alarm sounds as soon as a temperature rises or falls outside a specific set of parameters.
Due to the nature of research conducted in the chambers, a chart recorder was still a required part of the system. Affinity Energy replaced the outdated chart recorder with a new circular chart recorder by Future Design Controls. It saves on cost, without compromising accuracy.
Even with researchers going in and out of the room throughout the day, the prototype control solution has held the temperature steady within a half a degree Celsius.
With their new universal controller, and the code supplied by Affinity Energy, UNC Chapel Hill has the freedom to introduce future enhancements into their system with their own personnel. As the university integrates this new control solution into the rest of their environmental chambers, all they have to do is copy it, with a few minor calibration tweaks for each room’s specifications.
UNC Chapel Hill’s future plans include full access to room temperature and alarm history via remote access, which will provide critical data to researchers regulated by the FDA, Joint Commission, and other organizations that require historical data.
Keeping temperatures within a half a degree Celsius, with researchers going in and out all day long is not an easy thing. But Affinity Energy’s integrated solution has been running flawlessly.
Steve Hargett, Facilities Maintenance Supervisor, UNC Chapel Hill