In two previous articles on these communication protocols, we briefly updated you on what exactly Z-Wave and Zigbee are. If you are yet to read these you will find them here Z-Wave and ZigBee.
In short: ZigBee and Z-Wave are so-called communication protocols: just like Bluetooth and Wi-Fi, they ensure that devices communicate with each other. However, the difference between these is that ZigBee and Z-Wave have been specially developed for Smart Home purposes:
Both create a network of communication lines. Not only from the transmitter (also called Hub or Bridge) to the device, but also from one device to another - this is also called a mesh network.
This has the advantage that if the connection between the Hub and a device is lost or cannot be established, it is made by a signal from another device (if this is set as a signal amplifier or repeater). Allowing devices outside the range of the Hub to also be controlled.
Finally, ZigBee and Z-Wave devices use very little energy, so that they often will work on batteries for years and do not necessarily have to be connected to the mains. This is due to the fact that they only have to send small amounts of data. Only devices that act as repeaters are usually connected to the mains because they consume more energy. In an average household it is not usually necessary to use repeaters, because devices usually fall within the range of the Hub.
Comparison Z-Wave and ZigBee
We compare both protocols on a number of points, which we believe are relevant to the average consumer:
One of the most important factors in setting up or expanding your network of Smart Home products is mutual compatibility. In short: the extent to which devices can be mutually connected and can communicate with each other. Of course, if you buy a new motion sensor you will want to be able to link it to your existing alarm system and activate it.
ZigBee is an open source network meaning that manufacturers who integrate ZigBee into their products can make adjustments themselves in the software to match it to the product. As a result of this, not all Zigbee devices can communicate with each other effortlessly. If you want to expand your Zigbee network with a different brand, always check whether the product can cooperate with your current devices. Major brands that use Zigbee include Philips and Samsung.
Z-wave is developed by one company and all products that use Z-wave contain the same chipset. For that reason, almost all Z-Wave products can work together, and you can effortlessly expand your network with products from different manufacturers. In theory, you could link every brand of smart security camera to your indoor lighting and sound system, as long as they communicate via Z-wave.
In practice, however, these functionalities must also be implemented in the manufacturer's app and that is not always the case. So also check Z-wave devices to see if they meet your needs and are compatible with your current Smart Home products before purchasing them.
Range and stability
ZigBee and Z-Wave devices, use signals at a certain wavelength to communicate with each other. How far do these signals reach? That depends entirely on the level of noise in the environment and varies from a few meters to tens of meters.
Compare it to the following: you are in a disco where the music reverberates so loudly through the speakers that you cannot be understood by someone standing one meter away. Even though you scream the lungs out of your body. Why? The ambient noise (the noise) around you is so loud that your voice does not reach far.
The same principle is applicable to sending signals through devices. Due to electromagnetic noise from all devices that send signals to each other, they have a hard time making themselves understood. The more devices you have at home, the 'busier' and the less range the signals have. Walls, ceilings and other objects that are located between the transmitter and receiver also influence the range and stability.
Fortunately, ZigBee and Z-Wave work with devices that also serve as repeaters: they send signals to other devices that are outside the range of the Hub to ensure that they do what you ask them through the app. Think of them as an intermediary who tell a story to the recipient, without loss of information.
It is generally said that Z-Wave has less noise and is more stable, because it uses the 868 mHz frequency which usually has interference from fewer household appliances. Zigbee uses the 2.4 GHz frequency, which includes WiFi networks, Bluetooth, microwave ovens and many other devices.
You could say that the 'Z-Wave discotheque' is a bit quieter than the 'ZigBee nightclub', but for a normal household both networks have sufficient range to provide all devices with signals.
Earlier, we indicated that ZigBee and Z-Wave consume much less energy than Wi-Fi. This is since Wi-Fi has to transfer a lot more data, therefore requiring more capacity and computing power resulting in more energy expenditure. Products that communicate via Wi-Fi must therefore always be connected to the mains.
ZigBee and Z-Wave devices only need to send or receive a very limited amount of data: for example, the 'go on' command to the lamp in the corner of the TV. This is vastly different than using your Wi-Fi network to stream all seasons from Game of Thrones to your laptop. That is why Smart Home products work on batteries for such a long time.
If a ZigBee or Z-Wave device set up as a receiver because the next device is outside the range of the Hub; then it required to receive the signal, amplify it and forward it to the next device. This costs a bit more energy and therefore receivers must usually also be connected to the mains. Although it is not often necessary in practice to use receivers in an average household.
Which is better: Z-Wave or ZigBee?
Based on the factors we have discussed above, and our knowledge on the functionality of both protocols, the answer to the question is: neither of them, if you assume private use at home.
If you want to automate your home, it does not matter if you use a ZigBee or Z-wave device. Both have sufficient range, consume little power, are well secured and have plenty of products available that work with either protocols, or are even compatible with both.
You can also connect enough devices in both cases to make your home completely smart. With Z-Wave, the maximum is 232, whereas Zigbee can hold up to 65,000 devices in one network. As a business, we imagine that the 232 devices is quickly passed and resulting in an upgrade to a Zigbee products in order to set up a larger network.
If you are already a loyal consumer to other brands this should also come into consideration. For example, if you have already set up an expansive network through Philips Hue, you should consider buying ZigBee products as they work within the ZigBee protocol.
Important: if you are looking to expand your Smart Home network with a new device that can communicate with your current devices, then you must choose a device that supports the same communication protocol! ZigBee products cannot communicate with Z-Wave products and vice versa. This needs to be taken in to consideration as ZigBee and Z-Wave products do not always work well together, so always check brand compatibility before you make a purchase.