Designing efficient office buildings with visual appeal: Automation and controls
- Jason Gerke, Mechanical & Plumbing Group Manager, GRAEF, Milwaukee
- James Hansen, PE, BEMP, LEED AP, Principal and Senior Mechanical Engineer, GHT Ltd., Arlington, Va.
- Tyler Jensen, PE, LEED AP, Senior Associate, Environmental Systems Design, Inc. Chicago
- John Yoon, PE, LEED AP, Lead Electrical Engineer, McGuire Engineers Inc., Chicago.
CSE: From your experience, what systems within a building are benefiting from automation that previously might not have been?
Gerke: One item that has provided a direct energy savings is automated controls for window systems. These include automatic tinting of the glass or shading systems, internal and external to the building envelope, that prevent direct sunlight from reaching the glass. These systems appear have simple controls with today’s technology; however, they have not been in mainstream use for long. The continued development of technologies such as these and others that affect occupant comfort and a reduction in energy use are important strategies that must continue as we constantly work to reduce the energy consumption in buildings.
Jensen: Recent office buildings have taken an integrated automation approach where many building subsystems come together, such as temperature controls, lighting control, security, destination dispatch elevators, and beyond. This provides a central location for operators to more efficiently operate, monitor, and maintain their buildings. It also facilitates intelligent office buildings, where end users can use their smartphones to share digital credentials for access control, adjust lighting and temperature in their space, reserve conference or amenity space, and otherwise interact with the office building.
Yoon: Most of the expanded functionality of automation systems is being driven by the requirements of energy-conservation codes, such as International Energy Conservation Code (IECC) and ASHRAE 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings. We’re seeing an increase in the application of demand-control ventilation, adaptive lighting control for daylight harvesting, etc. None of these requirements should be unfamiliar to engineers who design projects in jurisdictions with current energy codes.
CSE: What unique tools are these facility owners including in their automation and controls systems?
Gerke: Automation systems for HVAC-related equipment are the things my group touches every day. Owners, at least sophisticated ones, understand how to leverage the automation characteristics of HVAC control systems to benefit their facilities staff. Tools in control systems that recognize when filters should be replaced-not just by schedule, but by pressure drop-are efficient methods to change filters when necessary, and not just because a schedule says it’s time. This minimizes the occurrence of filters being replaced too often or not often enough. This predictive-type maintenance is a tool that needs adaptation across a wider range of the market to take advantage of the collection and diagnostic opportunities built into today’s HVAC control systems.
CSE: Cybersecurity and vulnerability is an increasing concern-are you encountering worry/resistance around wireless technology and the Internet of Things (IoT) as the prevalence of such features increases?
Yoon: The potential of Distributed Denial of Service (DDoS) botnet attacks using IoT devices still scare most of the information technology professionals we work with. The earlier generations of IoT malware, such as Mirai, propagated via weak security practices (i.e., not changing default root/admin passwords on IoT devices). However, the threat is evolving. Many prevalent IoT malware strains are now exploiting firmware-specific security vulnerabilities.
The problem with malware is that it often lurks in the background and quietly propagates to new devices with little indication to the end user that anything abnormal is happening. You don’t find out how bad things are until all of the infected IoT devices are activated remotely at the same time. Then you get something like the Dyn DDoS attack that disrupted a significant portion of the internet in October 2016. With the increasing level of IoT devices, things can only get more difficult. For high-value IoT products, the manufacturers have a vested interest in regularly pushing out new firmware updates to address security exploits. But what about commodity devices, where price is the No. 1 consideration and security is No. 2? Or what about discontinued products that are no longer supported with new firmware updates by the manufacturer?
CSE: What are some design features and techniques should you incorporate to increase protection against cyberattacks?
Yoon: The most common design is to isolate IoT devices on their own dedicated network and then set up a firewall. However, the very nature of IoT devices means that they need to be readily and directly accessible on the network. Anything less will usually impact the functionality of the IoT devices. As such, there will always be some level of exposure. To avoid limiting functionality, security techniques often become reactionary-looking for anomalous network traffic through the firewall, and upon detection, taking action to restrict that traffic as quickly as possible.
CSE: What types of system integration and/or interoperability issues have you overcome in office buildings, and how did you do so?
Yoon: One integration/interoperability issue that we’re encountering more frequently is not necessarily in specifying new systems, but rather migrating obsolete systems that are at the end of their useful service life onto new platforms. More often than not, these systems are proprietary without any clear upgrade paths. When you integrate multiple functions (life safety, security, HVAC controls, lighting controls, etc.) into a single converged system, their replacement can be incredibly disruptive and expensive.
As engineers, we need to also consider the lifecycles of these individual subsystems and determine if the value of integration outweighs the cost and disruption when they need to be replaced. Some systems experience relatively little change through their lifecycle, such as fire alarm systems. There are other systems, such as lighting controls, that are regularly modified throughout their service life to accommodate building renovations and comply with updated energy codes. With these types of considerations, when does it make sense to specify traditional stand-alone systems as opposed to converged systems?