The Do's and Don'ts of Wireless Retrofits

Dec. 19, 2017

Building retrofits can be ideal applications for wireless devices but only when implemented effectively.

The Internet of Things (IoT) has opened a gateway to connectivity that facility managers are only beginning to harness. With the ability to add a wireless sensor or control to virtually every type of system, existing buildings are ripe for retrofits. The key is to start with a clearly defined strategy and then begin to deploy your mesh network.

BUILDINGS sat down with four industry experts to tease out the best ways to migrate to IoT. The panel consisted of Thomas Grimard, Associate Partner at Syska Hennessy Group; Troy Davis, Sales Director, EnOcean; Victor Berrios, Vice President of Technology, Zigbee Alliance; and Mark Quintana, Senior Associate of Information and Communication Technology at Syska Hennessy Group.

How can existing buildings benefit from wireless devices?

Grimard: Nothing needs to be siloed anymore. Everything is converged–systems know what the other systems are doing and can send bi-directional commands. This gives facility managers the ability to continuously retro-commission their systems.

Davis: Cable-bound systems are not suitable when maximizing sensors and switches because it is too difficult and inflexible to provide each device with its own line. Without the constraints of cable, sensors for smoke detection, occupancy, temperature, air quality and lights can be installed exactly where they are needed. This also provides the flexibility to retrofit a system with new products and additional sensors without having to break walls.

Berrios: The smart building market will not flourish if there is vendor lock-in. Facility owners need more choices for wireless, open standard products and services that are easy to buy, install and use. Wireless technology allows building operators to elevate their level of connectivity and efficiency with no infrastructure changes. The technology also supports tenant reconfiguration without compromises for the wireless network.

Where should building managers start?

Grimard: You need a roadmap–you don’t put technology in for technology’s sake. It needs to fit with your business plan. Keep in mind that IoT spans both wireless devices and cloud storage. When you start integrating these mesh networks, you are creating virtual data. Set up dashboards with a cloud-based service that provides the horsepower you need to manage the data. Software as a service (SaaS) also has the added benefit of automatically updating graphics and capabilities.

Quintana: You also need to have a vision of your end goal. Any system can have standalone wireless devices, but getting multiple systems to talk together is much more challenging. For example, you need to have a strategy on how to integrate 20-year old HVAC units with a new lighting system.  

Berrios: Another challenge lies in the need for network planning and deployment to ensure wireless coverage throughout the facility. With the proper upfront analysis and planning, deploying an effective number of routing nodes to cover the entire building is easily managed.  

Grimard: One aspect that is often overlooked is that these systems may not have standardized naming conventions for the data. For example, we had a client with a multiple-building campus where the naming conventions are different in each building, even though they all have the same control system installed by the same contractor. Because there wasn’t a data migration plan, integrating the legacy HVAC with analytical software and other low-voltage systems like lighting and shades has turned into a difficult process.

When systems share the same or standard naming conventions, they can communicate more effectively and building owners will be able to analyze, trend and derive value from the data better because the mapped data points will match the standard tagging in each building.

Follow the guidelines from Project Haystack, which is supported by CABA (Continental Automated Buildings Association) and ASHRAE Standard 205.

What security or bandwidth safeguards should be addressed?

Berrios: IT staff need to ensure that the network is planned for efficiency and expected usage so user effectiveness isn’t affected. Typical items found on IT department deployment checklists include network infrastructure planning, policies and control for new device commissioning, device health monitoring and management, user education and control of physical access to devices in the network.

Quintana: You also need to ramp up your network security. Investigate how adding wireless devices might make you more vulnerable to attacks. Ask manufacturers about their encryption standards–there should be encryption at the device level as well as on the server or cloud end so your information is protected. Network admins will need to be educated about new wireless devices, and how to securely manage all the data being communicated throughout the space.

Jennie Morton is a contributing editor for BUILDINGS.

IoT Applications by Building System


Everything from meters and temperature sensors to heating coil valves and actuators can benefit from wireless communication to save energy, reduce lifecycle costs and improve thermal comfort.
“Metering and high-performance systems need a mechanism in place that continuously monitors them,” says Grimard. “Say you have 100 AHUs across multiple buildings. A basic control system can’t tell you if any one of the units is degrading or deviating from the operational setting because of a software or hardware issue. Analytics can automatically find issues, patterns and faults and have the power to predict and diagnose problem areas before failure.”

“If you have a conference room with a smart scheduler, it can be synchronized with the A/V, lighting and shade systems,” Quintana explains. “It can recognize when a meeting is starting and adjust the systems to the number of expected people and usage of the room. This simplifies user access to all of the systems.”


Lighting has long been boosted by motion and occupancy sensors, but even greater efficiencies can be captured when those devices can talk to other systems.

“Daylight sensors can both adjust shades to take advantage of natural light and tell the lighting controls to modulate down. If there’s too much heat gain from the sunlight, a temperature sensor can also register that the VAV box is at 100% and simultaneously command the shades to lower and the lights to ramp up,” according to Grimard.

“In offices, laboratories and creative spaces, seat occupancy can be assessed with presence detectors and the use of devices can be determined with power meters,” Davis says. “Using room data such as temperature, brightness, CO2 and moisture, operators can create room usage profiles and correlations with the effectiveness of individual workplaces.”


Access control and surveillance systems are ideal opportunities to add analytics and open a window into trends beyond security.

“With contact, motion and exception condition sensors, wireless technology supports security needs ranging from the management of egress points in a building to the movement of assets within a given geography,” says Berrios.

“In hotels and dorms, the combination of window contacts and motion sensors is an ideal way to increase security and energy efficiency,” observes Davis. “A closed window protects the room against bad weather, avoids unnecessary heating and prevents false motion sensor alarms caused by the wind. Combining the sensors with available weather data on the internet is also useful. In senior living, motion sensors in mattresses, fall and presence detectors and flexibly positioned emergency call and control buttons supply urgently needed information.”

“On the camera side, analytics can be used for people tracking. They can cover a given space and count how many people are there and at what times. The extracted data can be used to design or balance those areas more efficiently,” explains Quintana. “If a conference room holds 10 people but the average meeting is only two, then it’s a waste of space. The data gives you a green light to break up or reconfigure the room so it’s in sync with actual usage.”

EnOcean vs. Zigbee

The Internet of Things is built on multiple communication protocols. In fact, you’ve already been exposed to several protocols if you use devices with Bluetooth, BACnet or Wi-Fi. However, building-specific devices commonly rely on one of two wireless protocols: EnOcean or Zigbee. Troy Davis of EnOcean and Victor Berrios of Zigbee describe features of their respective protocols.


While the overwhelming number of IoT sensors use wireless radio, many products still rely on batteries. This could result in expensive and time-consuming maintenance efforts. Imagine a hotel that has 1,000 devices that require a battery. The solution is to use energy harvesting wireless technology. EnOcean is an essential element to create a comprehensive network of self-powered wireless sensors.
Energy harvesting wireless modules convert kinetic, solar or thermal energy into electrical power. Together with ultra-low power electronics, self-powered IoT devices communicate on open radio standards. These flexible and maintenance-free sensor solutions help to make buildings more energy efficient and cost effective to operate. In retrofits, self-powered switches and sensors can be placed nearly anywhere without having to modify the existing layout.

— Troy Davis, Sales Director, EnOcean Inc


The Internet of Things is helping to connect devices to each other regardless of brand to bring new possibilities in linking various and formerly siloed objects to one another. The value Zigbee technology brings is that it’s an open, interoperable mesh IoT solution available to manufacturers. We want to work with wireless protocols and products that not only connect but interoperate with other wireless brands and products.

We promote the use of smarter, greener IoT standards for use all over the world. We have a feature called Zigbee PRO with Green Power, which eliminates battery usage and waste. It integrates battery-less or lifelong battery-operated devices into a Zigbee network so building maintenance and IT can add nodes and devices to the network that are virtually maintenance-free.

— Victor Berrios, Vice President of Technology, Zigbee Alliance

About the Author

Jennie Morton

A former BUILDINGS editor, Jennie Morton is a freelance writer specializing in commercial architecture, IoT and proptech.

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