In Volume One of Planning Your Smart Home we talked about Wi-Fi and how planning your network implementation and choosing the right products and their layout was so important to the overall success of your network. Well, Wi-Fi is not the only network in play in the modern smart home so next up we will be talking about Z-Wave and how to properly design its mesh network and the effects it will have on your smart home.
First up let’s talk a little bit about Z-Wave and what it actually is. Z-Wave is a wireless, low-energy mesh communications protocol allowing for a node to node communications back to a central gateway. Z-Wave was first developed my Zensys based in Copenhagen in 2001 for use in a lighting control system. Z-Wave is a proprietary system on a chip protocol that runs in the 900 MHz range and is currently in its fifth generation (or series 500 which is also known as Z-Wave Plus). Since 2001 Z-wave has changed hands a couple of times, first in 2008 when it was purchased by Sigma Designs and then again in 2018 when Sigma sold Z-Wave to Silicon Labs. AS of 2018, there are over 2400 Z-Wave Products certified by the Z-Wave Alliance which consists of companies like Ingersoll-Rand, Samsung, Bosch, Jasco, Nortek, and Leviton.
Now you are probably asking yourself, What does all this mean to me? Well, not too much, what you really need to understand out of all of that is the Z-Wave is a mesh network the operates in the 900 MHz range. Now the only other thing to consider is that not all Z-Wave devices will act as signal repeaters. Only mains powered (connected to your homes electrical system) devices will send and receive signal so that is very important when planning out your network.
I recommend that all users start building their mesh networks with the mains powered devices. If you get these devices in place first it will save you headaches down the line. I also recommend that when pairing these devices that you bring your Z-Wave Gateway right up close to it so that it can pair directly to the gateway instead of going through another node. Now you might say that sounds great on paper but some of my mains powered devices are on the opposite side of the house as my Z-Wave Gateway and they will never work once I put the Gateway in its final resting place. To that I am going to tell you that is fine, Z-Wave gives us a wonderful tool call network rediscovery which will allow your Gateway to go back out and pole the nodes and find the best routes to all of them. Another tip I try to give everyone is to have at least one mains powered Z-Wave device in every room of your home. This can easily be done using dedicated Z-Wave repeaters, but I have never been a fan of a device that takes up an outlet only to repeat signal when you can get a device that can serve multiple functions. In my home, for example, ninety percent of my lighting is Lutron (not Z-Wave) and most of my sensors are Z-Wave. I had a problem however with sensors in three of my bedrooms making it back to my SmartThings Hub. Simply changing three light switches to GE Z-Wave Dimmers solved the problem.
Once all of your mains powered devices are connected to your Z-Wave Bridge move on to your battery powered devices. Remember these devices will not repeat Z-Wave signals from other devices so they will not strengthen your mesh network. That being said I strongly recommend enrolling them that same as your mains powered devices, with your bridge close to them so that they connect directly. Again do not worry about the final placement of your bridge yet and if those devices can reach it as when we are done adding devices we are going to use our helpful friend network rediscovery to properly build our final mesh. The other thing that I recommend looking out for is adding too many devices at one time. I have always been a strong believer in adding one device at a time. That means putting your Z-Wave bridge into enrolling mode, doing what needs to be done with your Z-Wave device to get into enroll mode and then when enrolled in exiting enroll mode on your bridge. I know a lot of Z-Wave bridges allow you to add multiple devices in one enrollment session but trust me this is not a good idea, you can quickly lose track of devices this way. To repeat enroll one device at a time allowing your bridge to fully exit enroll mode before repeating the process for your next device.
Now there are also some general tips that can be used with battery powered and mains powered devices that you should be aware of. The best example of this is what to do when you have a device that will not pair. See Z-Wave devices can only be paired to a single bridge but can be excluded from a bridge (essentially factory reset) by any Z-Wave bridge. So if you ever find yourself in a position where you can not get a device to enroll always try to unenroll it even if it was brand new in the package. I have seen more device pairing issues solved by doing this than any other method and it is something that can save you a lot of time. The other thing to keep in mind is our trusty friend network rediscovery. Chances are you are not going to build your entire system in on go, you will add and change things as time goes on. Do not forget about network rediscovery, run it after every session of adding devices and also give it time to do its job. I recommend starting a network rediscovery right before you go to sleep. This ensures that nothing in your system is messed with while it is doing its thing and will give it plenty of time to complete and build that strong mesh network that you need.
Keeping these tips in mind when planning and implementing your Z-Wave network should reduce or eliminate issues for the most part but things will come up, fortunately, we with a proper plan and knowing the tools at our disposal we should be able to overcome any issues.
What issues have you run into when designing a Z-Wave network? Let me know in the comments below and we will see if we can address them together.
I am passionate about the IoT and connected devices. Using connectivity to automate our lives will empower civilization to achieve greatness.