Chiller Plant Manager vs. BMS: What's the Most Efficient?

Many larger structures pair their HVAC systems with chiller plants to keep their indoor spaces cool. According to the US Department of Energy’s (DOE) Energy Star program, only 18% of commercial floor space in the United States uses chiller systems. But that number rises to nearly 40% when we look at commercial buildings over 100,000 square feet. Chiller systems are common in airports, shopping malls, factories, hotels, and hospitals.

Like other building systems, chiller plants can greatly benefit from being integrated with a building management system (BMS), particularly if you want to optimize energy efficiency.  Chiller plants can work within a BMS and don’t require separate industrial controls. Chiller plants perform at their best with centralized control and the kind of advanced automation only an intelligent BMS offers. By exploring the role of a chiller plant manager vs. BMS, you can gain the insight you need to make the best choice for your operation.

Chiller Plant Manager vs. BMS

There are no federal minimum standards for the efficiency of chiller plants, but efficiency should be a top priority in any facility using these systems. That means looking at both the chiller and the way it impacts other building systems.

Though computerized chiller plant managers have advanced considerably, their ability to reduce energy consumption and increase efficiency is limited. Installing a chiller plant manager with industrial controls will make a chiller’s operations more efficient, but it will not create efficiencies throughout the rest of the building. 

Chiller Plant Manager

A chiller plant manager with separate industrial controls can reduce energy consumption by up to 25%. Traditionally, these controls focus on:

• Measuring temperatures.
• Creating arrangements for operating chillers under maximum load.
• Adjusting water condenser setpoints to reduce the use of cooling tower fans.  
• Determining the maximum load for cooling towers.

Modern siloed chiller plant management systems use advanced logic techniques and adaptive computer controls. Some manufacturers of chiller equipment have even begun optimizing their controls. This may allow you to enact a variety of strategies to improve operations, such as:

• Resetting chilled water temperature.
• Resetting condenser water temperature.
• Relieving cooling tower temperatures.
• Varying condenser water flow.  

But when comparing a chiller plant manager vs. BMS, the former will only increase efficiency in the cooling plant, while the latter can increase efficiency throughout all the facility’s systems. 

BMS 

A smart BMS can do everything a chiller plant manager does but provides additional, more advanced capabilities. 

A BMS integrated with analytics and IoT technologies gathers and aggregates data from all connected systems. This building data is centralized and can be looked at holistically, uncovering trends and providing deep insight into complex relationships within your building. It also gives you the information you need to make better decisions and implement advanced automation. 

Automation is a key differentiator of a chiller plant manager vs. BMS controls. While a chiller plant manager can automate a limited number of functions, a BMS greatly increases automation opportunities and precision. 

Optimizing Your Chiller Plant

To compete with more advanced technology, some controls manufacturers are integrating chiller plant equipment in a way that mimics BMS processes. However, this typically applies only to specific equipment data that can be easily optimized, such as the number of chillers, cooling towers, and pumps. 

True optimization requires unifying building systems using cutting-edge integration tools. These work with both proprietary and open-source hardware and software to enable seamless integration with your BMS. Such integration opens up extraordinary possibilities and provides significant benefits, including:

A variety of strategies can be used to optimize a chilled water plant in an integrated system. For example, you can install a variable frequency drive (VFD) to control power frequency in AC motors used to control chilled water-cooling system compressors. Sensor inputs from an integrated smart building system can then utilize a VFD controller to cut fan speed, reducing horsepower by several times. The result is lower maintenance and utility costs.

When comparing a chiller plant manager vs BMS, an analytics-driven BMS is invariably the superior choice. From optimized operations to improved energy efficiency, an intelligent BMS is an excellent investment that provides great returns.   

Buildings IOT designs and installs intelligent building management and automation systems. Learn more on how our contracting services can help optimize your facility’s chiller plant and other building controls.