For decades, traditional direct digital controllers (DDCs) were the only control option for building management systems. However, the emergence of application-specific integrated technology for zone-level control is driving contractors and integrators to investigate the advantages of a new approach.
"Our research shows that using today's integrated application-specific controllers instead of traditional DDCs can reduce installation time and labor costs by 75%," said Jason Estes, a business development manager for Schneider Electric.
Similar to DDCs, integrated controllers manage energy-related systems such as HVAC and lighting in a room or zone of a building. The key difference is that integrated controllers have the needed capabilities already built into the device, specific to the application for which it was designed, such as heating and cooling, occupancy sensing, and lighting, as well as HVAC equipment like RTUs and fan coils. An application-specific controller is as easy to install and connect as a thermostat because the sensor, programming logic, and wiring connectivity is integrated in a single device.
Pros and cons of room control technologies
HVAC technicians can program and custom-wire traditional DDCs to control any type of equipment; however, because each room controller must be individually programmed and connected, the time and resources required to install them creates a disadvantage. Installation can become even more complicated when considering that today’s controllers must manage numerous sensors. On the other hand, modern integrated controllers can simplify the installation process, making it possible to rely on an electrician for installation rather than requiring an HVAC specialist.
Today, many contractors and integrators are opting for application-specific integrated controllers and are saving on installation costs. In addition to savings, switching to application-specific controllers can open up new competitive opportunities.
Factors to consider when choosing controllers
Application-specific controllers provide other advantages such as higher profitability, faster commissioning, more flexible installation scheduling, and a less disruptive project for retrofit customers.
Other factors to consider before selecting an approach include:
1. Flexibility. DDCs can provide greater flexibility, but integrated controllers are much simpler and less expensive to install.
2. Time to commission. Shorter install times for integrated controllers offer the advantage of faster return on investment.
3. Risk factors. Integrated room controllers entail less risk of human error than DDCs, because they are tested and preconfigured to preclude programming mistakes. Also, simpler wiring (similar to installing a thermostat) minimizes input and output connection errors.
4. Retrofits or new construction. The easy and less disruptive installation of integrated controllers eliminates the need for ladders and enclosures and reduces the amount of work needed to be performed above a ceiling.
5. Networking. DDCs and integrated controllers can both provide networking capability to protocols such as BACnet®, LonWorks®, and Modbus®. However, integrated controllers may offer superior connectivity and integration to various control points and sensors.
6. Scalability. Scaling DDCs can be disruptive and expensive. Integrated controllers provide a plug-and-play environment, making it much easier to add or upgrade capabilities.
“Transitioning from DDCs to the newer technology requires some effort and a shift in habits,” said Estes. “But contractors and systems integrators can get up to speed with integrated application-specific controllers in a matter of days, because most major vendors offer educational materials such as online training and downloadable manuals.”
With the industry moving to a preference for such controllers over DDC technology, converting to integrated room controllers now can position contractors and integrators to compete.