The two questions we hear most from people deciding on a home automation system is, “what technology is the best? What should I use?”
There are so many great technologies out there. First, let’s start with Z-Wave, chosen because of its recent gain in popularity and cost. Z-Wave has been a very effective low-cost technology to allow the masses to take advantage of all the benefits automation has in store for them. This technology features the most options available for products with over 250 manufacturers now making products with the Z-Wave chip inside. Z-Wave has gone mainstream in the US quickly with the help of these manufacturers and the Z-Wave Alliance. To understand Z-Wave, you need first to know the basics of Z-wave, and then we will go into the pros and cons of it.
It is considered a Mesh network, which has one controller and devices (nodes). The controller can be anything such as an alarm system, automation controllers, thumb drives, or even handheld controllers. The devices are anything that receives that Z-Wave commands and then retransmit it. Devices better known as nodes include switches, plug-ins, locks, thermostats, relay outputs, and contacts – the list goes on. The controller transmits the signal and the devices receive this and send it to the next device, and so on. Now let’s discuss the more detailed part, and we’ll tell you all of the pros and cons of this technology.
CONS of Z-Wave
The Range on Z-Wave and Interference
Z-Wave says it has a 100-foot line of site but rarely is this the case. Z-Wave utilizes a 908.42MHZ RF signal. This signal has a larger wavelength which helps it go through walls easier, but this significantly affects the range. A safe estimate is 10-20 feet between each device. It depends a lot on the material in your home. Additionally, being an RF signal, it is rare but possible for things to interfere if on a relative wavelength. This includes devices such as some baby monitors, remotes, or anything in the 900MHz range.
Limitation of Size with Z-Wave
Z-Wave is a great technology for most homes under 3,000 square feet. However, with larger Z-Wave projects there are a few issues that can come about. Z-Wave uses the mesh network to extend the range by a string of connected devices. When a device sends the signal to the next device that is called a hop. Z-Wave is limited to a max of four hops in a line. So if you have any devices further than four hops, it won’t receive the signal. There are solutions to this problem, but it can be more complex and require pairing multiple controllers.
Popcorn Effect with Lighting
These are small limitations that some people mind and others do not. Lighting is usually the key component in an automation system. When you set up a scene with automation, then that scene will control a set of devices. You could have a lighting scene that turns some lights off and others on at different percentages. Z-Wave has a popcorn effect with lighting. There will be small lags in-between the scene of the lights turning on. The lags depend on how your mesh network is configured. These can be a split second or even a couple seconds long.
Z-Wave does have a small amount more latency versus a hardwired system, powerline system, or another RF system. Radio frequencies are limited in speed versus a system that is hardwired. These minor delays are not significant but can effect using occupancy sensors to activate lights. With a mesh network, each device processes the signal and sends that signal to the next. Fractions of time are used to process the signal and transmit it, which causes the minor delays.
PROS of Z-Wave
Price and Variety
The biggest advantage that Z-Wave offers is price and variety of products. Z-Wave can be a low-cost solution to automation because it allows over 250 manufacturers to produce electronics with the Z-Wave chip in it. This mixture of manufacturers creates a competitive environment versus some proprietary automation technologies that only come from one manufacturer. There are also thousands of different products that you can choose from with Z-Wave. Products include light switches, locks, water sensors, motion detectors, garage door modules, I/O modules, shut off valves, and many others, with new ones coming out almost weekly.
Z-Wave is a wireless RF protocol which makes it easily installed in new construction and retro. Being wireless you do not have to run wires to the devices for communication. This wireless functionality also makes it convenient for battery powered devices such as locks, contacts, and motions.
Z-Wave has opened up automation for the do-it-yourself market and alarm installers. In the past, automation has been a complicated process that often requires a specialized programmer. There are over 50 different controllers you can choose from to control your Z-Wave products. Some of these controllers are alarm systems, stand alone, and interfaces for other controllers.
Now that you know some of the limitations and the benefits of Z-Wave you can decide if it is right for your system. Some people prefer a hybrid of different automation technologies when doing automation. Consider the size of the system, what are you trying to control, and if some of the minor limitations of Z-Wave will affect your system or preference.