Wired or wireless sensors? The advantages and disadvantages of wired and wireless systems

There’s such a strong argument for installing sensors and automating building controls that many organisations we talk to are already convinced it’s the way forward. But what people do want to know is whether they should opt for a wired or a wireless system.

Here we’ve taken the five main factors you should consider when choosing smart sensors and run through the advantages and disadvantages of wired and wireless sensor systems.

1. Installation

A quick, straightforward installation is one of the main benefits of wireless sensor systems. When you consider that the vast majority of those adopting the technology will be doing so in an existing building, it’s not hard to see why this easy retrofit solution has gained so much traction.

Wireless systems could be your only viable option where hard wiring is difficult or impractical, such as in heritage buildings, glass meeting rooms, and other situations where there are construction limitations. For example, while running wires between buildings could be prohibitive, you could easily connect a neighbouring building to the network with wireless devices.

Installing wireless sensor systems doesn’t require any drilling, wiring or structural building changes. That means reduced installation costs, minimal disruption to your workforce and interiors, and a system you can get up and running much sooner.

In contrast, a wired-in sensor system means you’ll need to hire an electrician and more than likely pay an hourly rate. It can be a lengthy process with some necessary downtime, and drilling holes means some areas will need replastering and painting.

But while wireless system installation is often just a case of clicking or sticking the sensors into place, you do need to make sure the system is as resilient and offers as much coverage as possible by carefully planning the placement of sensors and receivers.

2. Cost

There are two factors to consider here – the cost of the components and installation and ongoing maintenance costs. And, contrary to what many people expect, a wireless system isn’t necessarily the more expensive option. That even rings true if you’re constructing a new build rather than looking for a retrofit solution.

While initial costs can be slightly higher for a wireless system, any modifications you make in future will be much cheaper. If you’re planning to expand your network in the future or you need some degree of flexibility – for example, if you sometimes move office partitions to change the configuration of the space – a wireless system is far more accommodating.

3. Maintenance

There are two types of wireless devices – powered and self-powered. In powered wireless systems, the sensors and actuators will all be battery powered. Before deciding whether that’s feasible, think about the size of your building and the number of devices. If you have a smaller building it might be fine, but a large building could prove impractical. Not only do batteries need to be changed, they also need to be stocked up and stored ready for use, then safely disposed of when flat.

Self-powered wireless devices harvest the energy they need to function properly. Tiny changes in movement, pressure, light, temperature or vibration are all that’s needed to power each device, making them virtually maintenance free. While this technology may be a bit more expensive initially than battery-powered devices, in the long run the system will actually be far more economical, as well as a much more sustainable choice for our planet.

4. Connectivity and security

Unfortunately, there are still a few misconceptions around wireless technology – that it’s not secure, that it’s unreliable, that you’ll forever be plagued by interference and signal-reach problems. In fact, these beliefs stem from early experiences with home security, entertainment and control systems, when signal difficulties were common.

Today, it’s a different story. Wireless products are everywhere, from tablets and mobiles to security systems and surveillance cameras. Most of these applications are high-bandwidth and very sensitive to latency (delays in data transfer), but still perform reliably and consistently. Building automation is a low-bandwidth application that’s not particularly sensitive to delays and latency, meaning wireless technology is more than capable of meeting performance demands.

Far from being a hindrance, wireless technology lends itself perfectly to IoT applications, allowing direct connection over Wi-Fi, 3G or 4G mobile data networks or local wireless networks. Many wireless devices have built-in intelligence that enables them to identify and link to the wireless building network automatically—simply pushing a button adds the device to the network.

Furthermore, wireless systems can be incredibly secure. In fact, wireless devices can use commercial, government, and even military grade encryption with multilevel authentication.

5. Flexibility and scalability

As we’ve already touched on, one of the biggest benefits of having a wireless network is that they’re really easy to add to or modify. That means you can easily reposition sensors to get a stronger signal, or if the room function or layout changes. Perhaps you have a modular retail or office space, with partition walls that change depending on use. Or perhaps you want a temporary installation in a rented building, or you’re trialling the technology before deciding whether to roll it out.

It’s also easy to scale up a wireless system over time – either as your workforce or business grows or so that you can stagger the initial investment. Wireless technology lends itself really well to this, since new sensors and receivers can be easily added to an existing network. Some buildings begin by automating control in a single zone – as a proof of concept, to measure results before proceeding, or to fit within budget constraints – and then expand from there.

Wireless technology also makes it easy to take advantage of upgrades and new technologies as they become available, allowing buildings to become more efficient and save more energy over time. This can significantly enhance the lifetime value of a facility.

We hope you’ve found this post useful. If you’d like to talk about which type of system might be particularly suited to your building, feel free to get in touch.