I'm a long time Hubitat user and recently have replaced my C-5 with a C-7. I'm wondering if I should put that old C-5 back into use, knowing I can link it to the new one, but I'm not clear on why to do this, what's the design intent here?
My home is long on one axis, so maybe this is about having z-wave and zigbee hub radios on either end of this axis? Is that a good design?
My home has dense building materials, such as stone on the facade. Could a second hub help overcome signal loss from devices in boxes behind thick rocks?
Is it a terrible idea to mix generations of hubs, given that the devices are also a mix of 400, 500 and 700 series z-wave radios. And there's also Hue zigbee stuff and some Ikea zigbee stuff around.
Thanks for helping me think this out.
Not really. Each hub makes a new/independent mesh. So putting either hub at the end of the long house is the wrong placement, both would need to be in the center, with repeaters on the end, for proper coverage.
I use my old C-4 primarily for LAN-based integrations and serving up dashboards, while my C-7 handles my lighting. Repeaters may also be enough to link your devices up to one hub, allowing you to do what I have with splitting more CPU intensive apps / devices onto one, with those that need more rapid responses kept on the C-7.
Yup I use my C5 the same way
I use two hubs one on each end of house. There is no place in the middle to place the hubs. I originally had one and the locks at the other end of the house were a bit flaky. I tried repeaters and I have a pretty solid mesh. Powered Z-wave switches in almost every room. When I got my C7 I kept the C5 where is was and put the C7 on the other end, and basically split the house in half. My House, like the OPs, is on a long axis, so I have two hubs one on each end. Thing's have been solid since. For me personally, it was the best option.
Yes, having multiple zwave/zigbee networks in the same house - one on each side, for example - can definitely work.
That's different than what the OP asked, but you're right that is another option of how to use 2 hubs!
Have you noticed any issues with your devices that could be due to this?
Two hubs could be a solution to that problem. But additional repeating devices with just one hub could work as well.
I have used three generations of the hub, for the most part, only one at a time. Briefly, I did use two hubs, primarily to segregate some misbehaving zigbee bulbs onto their own mesh, but I don’t use those bulbs anymore.
It all depends what problem(s) you’re running into with just one hub that you need to solve.
As others note, while this is theoretically correct, a hub placed at one end of a building can create a perfectly acceptable mesh, especially with decent repeaters. Two of my three hubs sit at one end of the building where they are located (one hub per building), and work beautifully. They're there because there is no good place to site them in the center of those buildings, which is often the case for people. I don't think most people need to worry too much about centering their hubs, practically speaking.
I ran 2 hubs (2 C-4s) by location for a while - one in the basement and one on our 2nd floor. It worked very well and provided some nice isolation in the event that one hub went down the other was still working so my system would never completely go offline. Also splitting up the tasks reduced overhead on each - ran rules local to each hub/devices. Back then used HubConnect but the native HubMesh will work fine for any device sharing - for centralized dashboards and such.
My current system is 3 hubs - 2 C-5's and a C-7. The setup is by "type" - The C-7 is the Z-Wave hub, One of the C-5's is for Zigbee Only and the other is dedicated to Cloud and Network devices (Alexa, Flume, Lutron, Homebridge). Note: I left the Zigbee devices on the C-5 because it has the same ZB radio as the C-7. This works well too...
Edit: I should note that the reason I did this was because I had the hubs on hand NOT because I went out and got the extras just for this purpose. It would take a very special use-case for me to start with this setup.
A bit like my rpi thread, the question quickly moves from "Why should I get a second Hub X?" to "Why should I have N of Hub X?".
You can NEVER have enough Hub X (and Y, and Z...) of course.