Wifi, ZigBee and Z-Wave: Which Is Best for your Smart Home?
11 October 2020
For many of you I’m sure this comes as more confusing technical mumbo jumbo. But in planning smart home technology and integrations it’s crucial to understand the differences between Wifi, ZigBee and Z-Wave and their strengths and weaknesses. I’m going through this process currently in regards to our smart home build so I thought it might be a good idea to get my thoughts on paper as it may also help others.
For quite a while, the predominant smart home protocol choices were either Z-wave or ZigBee. You’d pick a protocol and try to stick with it though it’s not as strict as that. As most smart home systems — cameras, sensors, lighting, etc. — are supported by smart hubs you could use both in your home. Wifi services didn’t have much support or centralized hubs to tie all the gadgets together until recently. But now, Wifi is a strong contender as more Wifi smart technologies are developed.
Wifi Takes It’s Place At The Smart Home Table
Lately it seems that every smart home manufacturer has promoted Google and Alexa integration and focused on Wifi radios instead of Z-Wave or ZigBee. Now, for every Z-Wave door lock on the market there’s a Wifi alternative, often from the same manufacturer. But not all things are equal between the protocols.
Z-Wave and ZigBee Focus On Local Processing
When building your smart home, you need to ask yourself how dependent you want to be on the cloud. All Wifi smart home devices depend on the cloud to work. You also need dedicated apps and the closest you can get to a centralized experience is syncing your devices with Alexa or Google. This doesn’t make the Wifi option bad but if your ISP isn’t dependable, like ours isn’t now at our rent house (thanks SuddenLink) then you could be in trouble.
But with hubs like Hubitat, Homeseer, or OpenHab, you can create a smart home that doesn’t rely on the cloud. This means that even when the internet is down, you can still control your smart home. And when you control your smart home locally, it also works faster. You’ll notice a dramatic difference between the time you send a command and it happens, like turning on the lights.
Z-Wave Takes The Road Less Traveled
Z-Wave devices in the US are also less prone to interference issues than either Wifi or ZigBee. The reason is that Z-Wave runs on a different radio frequency (908.42 MHz) than both ZigBee and Wifi smart home devices (2.4 GHz). 2.4 GHz spectrum tends to get very crowded with everything from your smart TV to your smart wearables. Z-Wave avoids this problem entirely as it only has to contend with itself, even if you add a multitude of Z-wave devices.
Z-Wave and ZigBee Do Have Limitations
Even when you use a cloud-dependent hub, like Wink or SmartThings, Z-Wave and ZigBee products benefit from company clouds involved in the process. Your hub does all the work locally, so if the company that manufactures your Z-Wave lightbulbs or ZigBee smart locks quits, your devices will keep working. As I’ve been a big SmartThings fan for some time this has been good for our smart home.
Wifi devices on the other hand, depend on multiple clouds. The manufacturer of the technology provides a cloud and a dedicated app. And if you control your smart home with Alexa or Google, their cloud is involved, too. But unlike a smart home hub, Alexa and Google Assistant don’t control Wifi devices directly as the various clouds communicate with each other.
This means if either side goes offline, your device does too. When Best Buy chose to leave the smart home business recently Insignia branded plugs, lightbulbs, and even a smart freezer all lost their smart home capabilities. With Wifi, anything in your smart home can break which can lead to everything in your smart home breaking.
But ZigBee and Z-Wave also have a giant and singular point of failure: the hub you use to control them. If that fails, either because the company quits or it just breaks, your whole smart home goes with it.
Wifi Devices Are Easier To Work With
Smart hubs can be a challenge to learn how to use though they’re getting better for the smart home novice. But they’re incredibly powerful and capable of advanced automation. That’s not necessarily the case with Wifi devices. You can pair them with Alexa or Google Assistant which are designed to be as user-friendly as possible.
While Google Assistant and Alexa routines aren’t as powerful as some smart hubs, they’re good enough for the average smart home. When you do need something more complicated, IFTTT and Yonomi work well with Alexa (but not Google, unfortunately). This is another reason I’m an Alexa fan as I use IFTTT to integrate some services.
Wifi Devices Are Generally Less Expensive
Wifi devices often cost less than their Z-Wave and ZigBee counterparts. When you compare Wifi plugs with Z-wave Plugs, Wifi Bulbs with ZigBee Bulbs or Wifi light switches with Z-Wave light switches, you’ll see a noticeable difference in price.
But building a smart home doesn’t have to be expensive. Regardless of which protocol you decide to build around, smart home expense can add up. But choosing Wifi due to the lower cost makes sense if it satisfies your smart home goals
Z-Wave and ZigBee Devices Don’t Work with Every Hub
Oddly, if you buy a Z-Wave or ZigBee device and own a smart hub that works with both that doesn’t guarantee they’ll work together. That’s why hubs continually release updates for new device compatibility. But if your hub doesn’t add new devices or is just slow to release updates, you might be out of luck. You can try to program the device generically, but that won’t always work.
With Wifi devices, you don’t have to wait or check to see if it works with your favorite voice assistant. Instead, the effort of compatibility moves from the your Alexa or Google Assistant to the device manufacturer. Manufacturers of Wifi devices can rely on APIs provided by Google and Amazon to make everything compatible. That’s less work overall because they only have to account for two scenarios. Z-Wave and ZigBee hubs are often significantly different and the amount of work necessary to sync everything together changes from hub to hub.
And The One to Pick Is …
If you want to ensure the devices you own will always work in your smart home, Wifi has a clear advantage, thanks to Google and Alexa. Whether you should go with Z-wave and ZigBee or Wifi depends on what’s more important to you when it comes to your smart home experience. If you want everything to work with Google or Alexa and don’t want to add smart hub complications, then Wifi devices are your best option.
But if you want local, cloudless control and a smart home you can fine-tune to the most advanced specifications then ZigBee and Z-Wave are for you.
Understanding your smart home goals is key to pointing you in the right direction, then the choice becomes obvious. I’m still going through that process but leaning heavily toward ZigBee and Z-Wave for the local compute power and speed. As Debbie and I will be getting our initial floor plans from our architect soon, we’ll start making a lot of these decisions soon. So stay tuned as things will really be ramping up in the next few weeks.
