Fan controllers - Way OT

I'm creating a somewhat "hardened" location for a NAS so I don't have to rely on off-site backups - sort of an Ethernet-connected cloud storage. There will be the NAS and a small UPS in some kind of (as yet undetermined) enclosure in a corner of a crawl space. Ventilation is not ideal so I expect I will need a fan or two. Temperature controlled computer case fans seem like a good solution but I'm obviously not going to be plugging them into motherboard fan headers. I'm going to need 12v power and some kind of fan controller with a temperature probe.

The power supply is probably not a problem. I've seen a number of small power supplies feeding a Molex connector. But I'm having trouble getting my head around the number and types of fan controllers. I could use some assistance.

A few key points:

1. The temperature setting needs to be either in non-volatile storage or be set by a knob or slider. This NAS setup is going to be fairly inaccessible. I don't want to have to re-enter the temperature setting if there is a power outage. (The UPS will help but we've had power outages that lasted days.)
2. My NAS claims to have a max operating temperature of 104°F / 40°C. I assume that means ambient temperature rather than the temperature of some internal component. The temperature in the crawl space is currently 67°F (with outside temperatures in the 90s) and never varies very much.
3. I think I want the fans to shut off when not needed rather than be running constantly a slow speed. (Unless the enclosure really traps heat I may not need the fans at all. No sense wearing out the fan bearings needlessly.)
4. I think I want the fan speed proportional to the cooling needed rather than a binary off / max.
5. I assume I will use 2 WPM-capable fans I've got lying around.

Anyone know of fan controllers that fit my needs?

CountMike said:

Which kind of case are you using ?

Yah, that's the next question ... and an important one. There are no cases or enclosures (that I know of) built for what I want. I want something with lots of ventilation and preferably with fan mounts. Both the NAS and UPS jus sit on feet - no provision for fastening them to the case.

There are a lot of small computer cases that would work as long as internal cages and partitions are removable (and I've heard the Cougar cases are good that way). But most computer cases don't allow for much passive ventilation. I would probably need fans running continuously.

Yesterday I saw an almost cubic case that had so many ventilation holes that it almost looked like mesh. But I cannot find it now (of course).

The size of the NAS is 6.5 x 4.2 5x 9.25 in (16.5 x 10.8 x 23.5 cm) + room for cables.
The size of the UPS is 3 x 6 x 10.5 in (7.75 x 15.25 x 26.75 cm) + room for cables (length) and plugs and wall-warts (height).
The fan power supply and controller will take room, too.

The Elite 130 might be a bit small even if I remove everything. (It might work if I set the UPS on its side but I don't know what that might do to the battery.) However, judging from the looks of that case, I'm pretty sure the one I thought might work was from CoolMaster.

There's really no reason the enclosure needs to be a computer case. I've been looking at those because I can find reasonably good descriptions of them ... and there's a chance someone on this forum has experience with whatever I pick. The enclosure just needs to provide a little physical protection when stuff is moved around in the crawl space and to make it easy to move all the equipment at once. A small wooden crate would work if it allowed for ventilation.

Now there's a high tech solution!

Actually, that is exactly what I need. Lots of ventilation holes. I'd have to rig up some fan mounts, drill some holes for cables, and figure out how to secure the components, but that certainly fits my requirements.

Now, back to the fan controller questions.

CountMike said:

WS16 DC 12V 4A PWM PC CPU Fan Temperature Control Regulator Thermostat Speed Controller Switch High Temp Alarm + Buzzer Sensor-in Temperature Instruments from Tools on Aliexpress.com | Alibaba Group

I had looked at that. PWM control ranging from idle to max over one of 4 preset ranges. It has 2 problems:

1. The lowest temperature range is 35° - 45°C (95° - 113°F) - doesn't kick in at a low enough temperature.
2. It does not shut the fan off - just leaves it on idle. (Pulse width for idle is selectable.

Coolerguys has a temperature controlled switch with a hard-coded range of 27° - 31°C (81° - 88°F) but is just on/off - turn on at the high temp; turn off at the low temp. I don't know if that is good or bad. The temperature range fits my needs but I would rather have variable speed - either PWM or voltage controlled - over the "On" range.