I saw in another thread a mentionof high hub temps (relating to C4's but I guess it could be any model). How are people monitoring their hub temps?
Most I believe may be using:
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Thank you!!
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I had, 'til yesterday, a C-3, a C-4 and two C-7's acting as my Production system. The C-3 and the C-4 were the two that had the majority of my devices. (One of the C-7 is ultra slowly becoming the migration destination of the C-3 devices.)
The C-3 and C-4 are the same other than the C-3 has no Hubitat logo. 
Therefore their temperatures can easily be different from C-5 or C-7 due to measurement differences. The importance really is the stability of the temp. If it's X degrees hotter or colder than another isn't as
important UP TO THE CHIP's LIMIT. I never saw any of mine hit the limit. No crashes or shutdown of Zigbee, etc to indicate a temperature problem. The numbers were high, but they are always high and the hubs always worked.
Here's a snapshot of my 4 hubs temps a week or so ago after adding a fan, inches from the hub.
The top and bottom tiles are the C-7's while the middle two are the C-3 and C-4. The C-3's temp is 10 degrees lower due to the fan than it was the hour before adding the fan. I saw no benefit from adding the fan, the hub didn't work "better" but the temp was lower. If I put my hand on the individual hubs, there wasn't much temp difference. The C-3/4's temp sensor was probably in a different location and was closer to measuring junction temp than the C-7's.
Yesterday, for amusement mostly, and because I had two C-5's acting as my development hubs, I could swap the C-3 and C-4 out. I'd lose my development system for a while but it's not like I can't swap back.
Here's today's snapshot of temps:
I want to make sure it's clear... The C-3 and C-4 report higher, much higher temps than the C-5 and C-7 but it never affected the hubs. I didn't swap out for a temperature reason.
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I think that's a reasonable hypothesis.
I'm more just curious than concerned with performance issues. Right now I have 3 total hubs. A C4 with the radios disabled running the rules and apps. A C7 housing all the devices and limited apps, and a C7 that I haven't figured out what to do with it yet.
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You could send me that C-7 and I bet I could have it doing things in just a few hours. 
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Hahaha... I'm sure you could! I'm actually thinking of having it replace the C4.. Just not sure if I want to get into rebuilding everything again. The current setup seems to work fine, so it's really one of those if it's not broken why fix it scenarios.
Well, I really WASN'T concerned with my hub temps, Now maybe i'm wondering if I should be
The first is the C4 with just apps and rules on it, radios disabled.
the second is a C7 with just devices and limited apps.
and the one below is the extra C7 with nothing really on it except a few apps for future use or monitoring
No, you shouldn't be.
Just for giggles, and because I can't sleep I tried flipping the hubs to have the vents face out.
C4, C7, C7 only a very slight improvement. I'm not going to worry too much about it. everything seems to be working fine as is.
So, what is the chip's limit?
Bump on this. I'm at 172F and considering removing the "sponge" and heatsink, and using artic silver and a real heatsink. Although the hub seems to run fine, I worry about it shortening lifespan and coming home to a dead house
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Hear hear, ditto that.
I keep hoping someone(s) might get their head around a possible way to create a totally redundant self healing hot swap for this very instance. I've heard all the no-it's-not-possibles from the folks that ought to know.
But...maybe part of this is doable... and another part of it is worthy input to the next iteration of Zigbee & Z-wave standards.
I'd buy a second set of hubs in an eye blink for this very purpose. And just think about the Marketing edge Hubitat could tout saying it offered this capability. Go ahead and tell me nobody else worries about this as their meshes get more and more functionally complex.
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There was a thread about internal temperatures a few months ago, but I do not recall anything useful coming from it. Mind you that 172F is about 78C - not really a taxing range for modern semiconductors.
Hubitat is funny, in that it is a software company that happens to sell a hardware product as a vehicle for the software. There is zero guidance on operating conditions or de-rating. On the other hand, I don't see threads discussing premature failure either. Not sure what to make of it.
A little update.
My C4 was ROUTINELY hitting between 185 and 197.I have my hubs mounted to the wall with 3M Velcro command strips. I turned them around so the base was facing out. I placed a pair of USB Computer Fan 80mm Cabinet Fans below them blowing into them. with this i'm averaging about 140 -150 for the C4 (though i will occasionally get s readings in the 30's somehow (no way that is accurate). The C7 runs between 107 and 115 on average
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I've re-purposed all my hubs in order to retire the C-3/C-4s.
I now have 2 C-7s and 2 C-5's in Production. I also have a C-7 as my Development hub (the 8th hub purchased, but with 3 retired, I'm still at only 5 )
For the 4 Hubs in my Production "array", I have a dashboard specifically for these environmental values. Here's a snap of them:
The pair in the Middle are C-5's with Radio USB externals from the C-4's that used to be in those spots. One is ZWave only, the other is both ZWave and my only active Zigbee radio.
The C-7 at the bottom is ZWave only and it's my intent that it will get migrated devices from the other two.
C-7 -- 0 ZWave devices, 160 total.
C-5 -- 31 ZWave devices, 74 total.
C-5 -- 28 ZWave devices, 74 total.
C-7 -- 27 ZWave devices, 40 total.
That top C-7 is my HubConnect Server and so almost all of the devices on the other 3 hubs also exist on the Server Hub because it's where my connections to Dashboards, Apple HomeKit and Alexa - Google Home exist.
All the temps are in a narrow range and don't move around a lot. They are all a degree or two higher due to summer atmosphere temps. It's interesting that the C-5's physical placement of the sensor is just enough different from the C-7 to be noticeable, but nothing like the difference seen to those C-3/4's. I also like to use degrees C because that's more directly comparable worldwide. I think the other columns are more intriguing actually, and was hesitant to add to a temp discussion with JVM, DB size, etc.
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I've debated on and off retiring that C4 and using the spare C7 instead. The C4 currently houses all my rules, integrations, etc. There are no devices actually on that hub, and the radios are disabled. It is connected by hub mesh to one C7 which is where all the devices and a limited number of apps live.
So, please correct me if I am incorrect, but I have been thinking I should be able to back up the C4, Disconnect it, then restore that back up to the currently spare C7 to take its place. Am I correct in that theory?
At one time I had all three connected with hub connect, but when I changed my router it changed my IP addresses slightly (changed the third number to 50 and I could never get hub connect to work after that.
As I'm looking around, this looks like it may be a better solution, particularly because it has USB ports built into it, so it could help in cleaning up the equipment area, minimizing the number of cords and devices in the equipment closet. I'm thinking I could mount the hubs to this the (grid down) the same way they are currently mounted to the wall, and mount this to the wall. Plug the hubs into it's USB ports. With the pictured side air intakes, it should have a good constant flow of air.
