Network Closet Fans- Ideas? Suggestions? Advice?

I am nearing completion of revamping my network closet that houses all my devices.
WiFi Router, Cable Modem, Cable TV Box, Switch, Smarthings Hub, Weather Station Transmitter/Receiver, UPS, Headless Intel NUC , etc.

I have all the components placed on individual shelves (4 total).
As part of the process I figured I would install some 5 inch 12 volt PWM Computer fans that could be mounted with spacers on the underside of each shelf and point downward towards the individual components.

That way I could use a sensor to monitor temperature and have the fan speeds modulated / controlled to increase or decrease based on the amount of heat from the components or in the closet itself.

Since the fans will be 12 volts I need to find an elegant solution to control the rate at which they spin.

Need suggestions as to

  1. Which sensor to monitor temperature of overall closet and / or the components thenselves
  2. How to control standard 12 Volt 5 inch or larger computer fans
  3. Use some other fan like device that will serve the same purpose

Not alot of room at the top of the closet so I cant install a big box fan and mount it to the ceiling. So thats out.

I can leverage the PC (Intel NUC) that has USB power plugs and also my WiFi Router has a USB plug on its face as well.

It would also be great to have this type of integration with Smarthings so I could also set high and low alerts / notifications . Like " Network Closet Temperature has reached 90 Degree’s" or Network Closet has reach High Temp Limit . Or Fan1 running at 80 Percent Temp is 82 Degrees.
Stuff like that would be kinda nice so I dont need to access the closet or open the doors all the time. The ability to feed the temperature to an LED display would be nifty as well , but not a top priority.


The rotating fan blades are likely to cause dispersion interference with your radio transmitter devices. Especially the low power ones like zwave and zigbee. Just something to be aware of.

I would move the smartthings hub out of the server closet all together into the center of the house and open air and then vent the closet rather than add fans to it.

Here’s a good example:

Even something like this with a fan attached on the inside of the vent blowing air out of the closet will typically work better than fans blowing air around inside the closet.

Fans don’t cool nonevaporative surfaces. What do you want is to increase the exchange of air with the parts of the house which aren’t as hot.

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This is a great idea! I already have a vent at the top of the network closet behind a rectangular grate. I also have a register in the floor that is just open to the cool air of the crawlspace under the home. So if I understand the idea . I would install the air circulation fan on the vent stack that is installed and runs up into the attic. Then the blades of the fan would pull air from inside the closet and from the cool air in the crawl space through the closet and reduce temperatures?

I guess I could also hardwire one of those ceiling fan switches to be able to control the rotation of the fan blades .???

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I don’t see the rotating fan blades as being a big deal. I would worry more about the proximity of the hub to the other RF devices such as your WiFi Router and Weather Station Transmitter/Receiver. You want to get at least a meter between them, further if you can.

For cooling, all you need to achieve is a change of air in the cupboard regular enough to keep the components from overheating. How hot do they get now?

Looking at your picture you already have a vent at the top. Hot air rises so you want to help that by allowing cool air in at the bottom (maybe with another vent) and using fans (blowing upwards) to help the air flow up past all your components to the exit at the top. Air is lazy and will take the easiest path so some ducting might be needed to force the cool air where you need it to go.

Unless noise is an issue I would not worry about modulating the fans.

The picture above is not of my actual setup , but one that was posted as an example of how one can place a vent at the top of the doors to allow air to circulate and escape.

I have my Hub on the top shelf and my WiFI router on the third shelf below it. There has not been noticeable issues that I can discern with them conflicting related to interference. So Im good there.

I have a vent at the top in the ceiling and a register in the floor that is just open to the crawl space below the house so cool air could be blown upwards from the area in the crawl space. I am going to investigate one of those duct blowers and some insulated HVAC flexible ducting . I think having it blow more air or less air with some type of regulation / control would be nice so that if the fan is not needed and the components are staying cool I can have it automated to turn off and if the components heat up then a little air circulation could be added.

I just need a Z Wave device that can control one of those duct fans that run off of standard 120 Volts AC 60 Hz. They have manual ones that one can turn like a rheostat , but I want a device that can handle that for me. As the fan will be in an area that is not easily accessible.

I have media cabinet for all components in our home theater. I installed two of these to pull air out of the top of a media cabinet, with open vents at the bottom.

Each is plugged into a z-wave outlet. While the speed is adjustable on the fan, it isn’t controlled via ST.

Repurposed a ZOOZ sensor to monitor temp/humidity.

I get various alerts based on conditions with auto-on based on harmony state and temperature.

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