The State of Technology: Building Automation Systems

building automation systems
Frank Arena, ERS, for Zondits. April 20, 2016. Image credit: RichardLey

Building automation technology has come a long way over the years, thanks to advances in communication, which have helped to drive the development of electronic control technologies. These advances have made what was once a sketchy and maintenance-heavy control scheme into one that is powerful and easy to maintain.

Communications have gone from stand-alone local communications over a proprietary Ethernet RS-232 or RS-485 communications loop to open protocol (BACNet, Lonworks, and Modbus) web-based systems that include Wi-Fi options. It is commonplace for multiple buildings to be connected through one BAS. Example situations using this level of integration would be buildings belonging to municipalities and college campuses. Security remains an issue for a lot of commercial/industrial, federal, and state facilities because of the potential exposure to other sensitive areas on the associated network.

Eliminating pneumatic controls in favor of electronic versions provides many benefits:

  • Improved signal response time – This means less hunting at valves and damper actuators.
  • Reduced energy consumption – Removing pneumatics eliminates the need to feed inefficient air compression systems that are dedicated to the control system.
  • Cost savings – Electronic control systems are less expensive to install and maintain.
  • More-responsive feedback loops
  • Less maintenance – Electronic controls do not require the constant upkeep needed for leaky, hard-to-calibrate pneumatic systems.
The push toward more-efficient HVAC equipment has allows it to keep up with what a new BAS can do. Click To Tweet

Wireless thermostats and controls have been coming onto the market over the past few years. This is an important industry trend to cover because of the cost advantages – eliminate the wiring, and you reduce implementation costs. Wireless systems can work well under the right conditions, but interference, reliability, and security with the wireless signals can cause problems, so they’re not a good fit for every situation. The wireless option should be explored in detail before it is implemented. Some people will do a mock-up of, say, one rooftop unit (RTU) being controlled with wireless devices to see how it works before they implement a facility-wide system. Often, a hybrid combination of conventional wired and wireless controls is the answer for areas that are difficult to wire. Check out the website for some pros and cons of wireless technology.

Data acquisition components, such as CO2 and humidity sensors, have also become more accurate and have longer life cycles. Some CO2 sensors use non-dispersive infrared technology with an auto calibration feature to prevent measurement drift and to remove the need for recalibration. There are new all-in-one sensors that include CO2, relative humidity, and temperature; these are especially handy for demand-controlled ventilation strategies.

The push toward more efficient HVAC equipment, which itself has been driven by efficiency codes and pure capitalism and vendor competition, has allowed the equipment to keep up with what a new BAS can do. Some of the larger equipment manufacturers have purchased major control brands and include top-brand controller options as an integral part of their equipment. So, now you can purchase an RTU complete with an integrated programmable controller with all of the necessary temperature and pressure sensors. The damper actuators will come wired to the controller; the integrated controllers will even come programmed with the appropriate control strategies. The trend toward consolidation (equipment manufacturers buying BAS companies) is creating a world of fewer independent controls manufacturers and a glut of controls contractors. Many contractors are trying to become systems integrators, using off-the-shelf hardware with a Tridium Niagara framework to create a low-cost BAS solution. There is also a trend to build systems off the Tridium Niagara framework. Tridium was an independent OEM, but it is now owned by Honeywell and still operates as a separate company. Control companies and system integrators such as Alerton Controls, Huntington Controls, and Invensys use Tridium Niagara as their framework operating system. Check out Tridium’s website.

A trend right now is real-time diagnostics to provide monitoring-based commissioning solutions. Click To Tweet

While the advances in communication and controller technology have increased the effectiveness of BASs, at the end of the day the value of a BAS is in its design, implementation, and upkeep and the degree of user training. The newest and most efficient technology improperly applied is going to end up functioning like an old, arthritic dog. For a lot of purchasers, the design of their BAS is a direct function of its cost. So, in most cases, the low bidder wins. This leads to the purchaser getting a BAS that almost meets their needs. They may end up with a solid shell that has been hollowed out here and there to keep the price point within a certain range. Then there is the commissioning of the BAS; this should be overseen by a commissioning agent who is working for the purchaser, not the contractor. I’ve seen a lot of well-designed systems that were never commissioned properly, and poor commissioning can often result in comfort and energy consumption issues.

The most relevant trend right now is real-time diagnostics to provide monitoring-based commissioning solutions. One of the leaders for continuous/monitoring-based commissioning software is FacilityConneX. Their software solution is based on supervisory control and data acquisition system (SCADA) algorithms and technology. SCADA is a type of control system used in manufacturing and industrial facilities that is more powerful from a programming perspective than traditional BAS software. Continuous/monitoring-based commissioning software tends to be an overlay system that operates on top of the BAS, but I expect that the capability will eventually be built into the major BAS companies’ software and will be offered as an option. Check out the FacilityConneX website to see an example of continuous/monitoring-based commissioning software.