Zigbee and Z-Wave are so-called communication protocols that - like Bluetooth and WiFi - ensure that devices communicate with each other. The difference, however, is that Zigbee and Z-Wave are specifically designed 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 devices can also send signals to each other. This is also known as a mesh network.
This has the advantage that if the connection between the hub and a device is lost or cannot be established, this is still done by a signal from another device (if this is set as a signal amplifier or repeater). Devices outside the hub area can also be controlled.
After all, Zigbee and Z-Wave devices use very little energy. This means that sometimes you will run on batteries for years and not necessarily have to be plugged into the mains. This is because you only need to send a small amount of data. Only devices that act as repeaters are normally connected to the mains because they consume more energy. In the average household, there is usually no need to use repeaters as the devices usually fall within the range of the hub.
Comparison of Z-Wave and Zigbee
One of the most important factors when setting up or expanding your smart home network is mutual compatibility. In short: To what extent can devices be connected to one another and communicate? Of course, you want your new motion sensor to be able to connect to your existing alarm system and activate it.
Zigbee is an open source network and that means that manufacturers who integrate Zigbee into their products can make adjustments to the software themselves in order to adapt them to the product. This means that not all Zigbee devices can communicate with one another effortlessly. If you want to expand your Zigbee network with another brand, always check that the product is compatible with your current devices. The main brands that use Zigbee include Philips and Samsung.
Z-Wave is developed by a company and all products using Z-Wave contain the same chipset. For this reason, almost all Z-Wave products can work together and you can easily expand your network with products from different manufacturers. In theory, you could connect any smart surveillance camera from your brand to your indoor lighting and sound system, as long as you communicate via Z-Wave.
In practice, however, these functionalities must also be implemented in the manufacturer's app, which is not always the case. You should therefore also check whether Z-Wave devices meet your requirements and are compatible with your current smart home products before you buy them.
Range and stability
Zigbee and Z-Wave devices use signals at a specific wavelength to communicate with each other. How far do these signals go? That depends entirely on the noise level in your area and varies between a few and several meters.
Compare it to the following: You are in a disco where the music is echoing through the speakers so loud that it cannot be heard by someone standing a meter away. Even when you scream the lungs out of your body. Why? The noise around you is so loud that your voice cannot reach far.
The same principle applies to the sending of signals by devices. The electromagnetic noise from all devices sending signals makes it difficult for them to make 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 between the transmitter and receiver also affect the range and stability.
Fortunately, Zigbee and Z-Wave work with devices that also act as repeaters: they send signals to other devices that are out of range of the hub to ensure that they are doing what you want the app to do. Think of it as a facilitator telling the recipient a story without any loss of information
It is commonly said that Z-Wave has less noise and is more stable because it uses the frequency of 868 MHz and there are typically fewer household appliances on the same frequency. 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 enough range to give signals to all devices.
Zigbee and Z-Wave use much less energy than WiFi. How can this be done? Wifi has to transmit a lot more data, so it requires more capacity and computing power and therefore consumes more energy. Products that communicate via WLAN must therefore always be connected to the power supply.
Zigbee and Z-Wave devices only have to send or receive a very limited amount of data: for example, the command "continue" on the lamp in the corner of the TV. This is unlike using your wifi network to stream all seasons of Game of Thrones to your laptop. That is why smart home products work on batteries for a long time.
Has a Zigbee or Z-Wave device been set up as a receiver because the next device is out of range of the hub? Then it has to receive the signal, amplify it and forward it to the next device. This costs a little more energy and therefore the receivers usually also have to be connected to the mains. Although in practice it is not often necessary to use receivers in the average household.
Which is better: Z-Wave or Zigbee?
Based on the factors discussed above, supplemented by our knowledge that goes into the functionality of both protocols, the answer to this question is: Neither of them, assuming private use at home.
If you want to build a smart home in your house, it doesn't matter whether you use Zigbee devices or Z-Wave devices: both have a sufficient range, use little electricity, are well protected and there are many products that work with everyone Protocol or even compatible with both.
Then your choice also depends on whether you are firm with the brand. Are you a big Philips fan and don't want anything else? For example, Philips Hue will soon have lights that use Zigbee. If you want to add a motion detector to your smart home that can control the Philips Hue lights when you arrive, it has to be a Zigbee device too.
Important : Would you like to add a new device to your smart home network that can communicate with your current devices? Then choose a device that supports the same communication protocol! Zigbee products cannot communicate with Z-Wave products and vice versa. On the other hand, Zigbee or Z-Wave products don't always work well together either. Therefore, always check which brands or products are compatible with each other.