At my automation company, Stratus Designswe are often asked about the differences between wired vs wireless sensors, the reasons behind our choices, and how we use them.

Wired vs Wireless Sensors

We have developed some standard offerings and applications that utilise either sensor, explaining why we chose to do so. Not all sensors are created equal, and sometimes it’s not just a question of wired vs wireless sensors. We have standardised horticulture-based sensors for all our agricultural needs. Choosing the right option for your grow is essential; you must also select a high-quality, long-lasting sensor. At the beginning of my career, someone told me they were too poor to buy cheap tools. That saying also applies to buying sensors: spend the money on the right one, and you will not regret it.

Why Select a Wired Sensor?

Wired sensors are the standard and, in general, the most reliable sensors when it comes to maintaining a connection and preventing data loss or control issues in your building. In general, wired sensors pull data as often as your BMS (building management system) requests it, and the data is always available. For this reason, we choose to use at least one wired sensor in almost all our applications.

For example, in a grow room, we typically install at least five sensors for temperature and relative humidity. One of those sensors is always wired, just in case we ever experience a glitch in our wireless system. Wired sensors are typically quite accurate and have a reasonable price point.

We recommend Greystone horticulture sensors as they are Canadian-made and have replaceable “pods.” These pods contain the sensor elements and are changeable. The sensor provides temperature, relative humidity (RH), and CO2 level readings. The pods are cost-effective and a great way to use the same sensor for years.

Are there any drawbacks to wired sensors? Users must pull a wire through the building and then return it to a central location, where it will be terminated to a control panel. The more wired sensors you have, the more expensive your system becomes, as you need more controllers. This is one of the reasons we use minimal wired sensors. If money weren’t a concern, we would use more wired sensors than wireless ones.

Why Choose a Wireless Sensor?

I took a long time to warm up to wireless sensors, as my experience with them over the years had been poor. At this point, I recommend only one horticulture sensor brand: Aranet.  They are a Latvian company offering excellent customer support in Canada and the United States. The reason we have standardised these sensors is because the wireless system is top-notch.

The protocol used has been “borrowed” from their parent company, which designs advanced systems for the military. I have never experienced such good wireless range and access to sensors as on this platform. The beautiful thing about these sensors is that they are also all IP67 rated, which means they are waterproof. When working with the crops, we have effectively no risk of damaging the sensor. Battery life is also incredibly long, and you can adjust the sampling rate. Aranet is the baseline; I don’t recommend any other wireless sensors I have used because there are too many walls and barriers.

Wireless sensors often experience issues with dropping off your network, making it very difficult to control a grow room effectively. If you are averaging all five of your sensors in the room and two of them stop transmitting the correct values, then your room may not be maintained in the right conditions. For this reason, it is vital to have a system that allows you to detect if a sensor is not reading correctly and remove it from your averaging control of the space.

Wireless sensors are ideal for finding microclimates in your rooms and moving them around with ease. Implementing a wireless sensor array is also more straightforward and faster to install.

The Verdict on Wired vs Wireless Sensors

If it weren’t for the risk of going offline, I would use Aranet wireless sensors for all my growing needs. We have implemented them in outdoor, greenhouse and indoor growing environments. Wireless sensors can give you significantly more data points to manage and watch your grow without the need for a substantial install cost and implementation. Remember that every wireless system experiences network hiccups, so plan to include at least one wired sensor for added reliability.