For your current chiller plant optimization project, what was an issue you noticed right away with the chiller’s existing operating system?
Two 1000 ton chillers had been added to an existing plant several years before we became involved with the client, and the plant had not operated well since then. The controls had never been commissioned, so everything was being operated manually, often in an inefficient mode. In addition to the energy implications, this negatively impacted the lifespan of the equipment at the facility, because the machinery was operating harder and for more hours than necessary.
What steps did you take to resolve the issues associated with the chiller plant?
Our tactic was to first spend time talking with the operators themselves. We found out their issues with the system’s operation, and the multiple complexities of the plant due to the layers of upgrades and projects that had been conducted over the years. It took a bit of sleuthing and some hands-on testing and data collection to determine why they were unable to operate certain chillers in certain configurations, or utilize their water-side free heat exchangers because of flow issues.
After the evaluation period we worked with the mechanical contractor and control vendors to develop a solution for optimizing the plant’s operation. This involved incorporating a third-party system optimization software into a new system sequence of operation, and coordinating among all different actors involved. Envinity brought everyone to the table to develop and implement a plan that now has produced significant energy savings. We are also commissioning the plant, to ensure that it operates smoothly under all conditions.
What is the benefit of having Envinity work on this system versus another engineering firm?
One of our benefits is that we are “system agnostic”; we only want what’s best for the clients in terms of operational reliability and energy savings. Originally, we were planning on implementing our optimized plant sequences through a standard control specification. However, the control vendor actually came back recommending a partner company that they thought could provide the level of optimization we were hoping to achieve. We helped the owner determine if that software would be the best option.
What are the non-energy related benefits of chiller plant optimization?
An optimized plant is far less labor intensive for the operator and easier on the equipment. The point at which the plant is operating at its most efficient is also easier on the equipment; noise is reduced when pumps, fans, and chillers are run at their most efficient operating points.
One of the greatest benefits is the added safety of automation and, critically, functional testing of all safety sequences. For example, before the project if a chiller went down on the weekend or when the operator wasn’t around, the off-hours staff had to deal with the failure. Now we have automated the backup chillers to be able to be brought online in the event of a failure. In many areas of a healthcare setting, but particularly operating rooms, having reliable and redundant chilled water is a critical health and safety issue.
Do you continue to monitor a project after you’ve implemented changes?
We stay involved after we have implemented a plan to ensure that it operates as intended. Our commissioning process continues for a year after the changes have been completed, to make sure that a system is performing as we expected through all the seasons and modes. In our experience, if that’s not done, then the chances of a system operating well over the long term is very low. We’ve seen systems of all types not work right because they were designed, built, and then walked away from. We are involved with our clients through our ongoing measurement and verification program after the project is complete.
What do you see as a general trend in the commercial building industry?
The industry is becoming more aware that even if you design the most efficient building, it isn’t going to perform correctly if it isn’t properly commissioned, and that performance is going to degrade unless it is monitored and maintained. Buildings systems are getting more complex which can result in better comfort and energy performance but these complex systems need to be periodically re-tuned and maintained.
Finally, what is your favorite part of your job?
One of the things I like about working at Envinity is that I’ve had the flexibility to do a lot of different things. It’s pretty unique that I was able to write the control sequence for the chiller optimization, help with the design documents, and was part of the construction administration on this project. This allowed me to be involved in every step of the process, and to really understand the system. I love the problem-solving aspect of my job, and the process of understanding complex systems. When we save energy, improve environmental quality, and allow the operator to do his job better, it’s really rewarding.