Fan control based on voltage consumption for furniture

[fwannmacher]

I'm building a custom furniture for my consoles and I want to put a glass door in front of each system to avoid dust. For heat dissipation i want to add fans for each compartment. The there is my problem:
I would like to have a way to auto turn on the fan of a specific compartment based on the console being on or not. So I was thinking about some way to do it based on the current used by the console. Something like a simple circuit between the energy socket and the plug.

I have no idea how to do that xD

Ideas? Suggestions? I appreciate any help

[Guspaz]

A good fan (like one from Noctua) is pretty much silent at lower RPMs, so one possibility is to just have all the fans going all the time.

Another possibility is to wire up a 5v fan up directly to the 5v power supply in the console. Some of Noctua 5v fans have quite lower power consumption, their 200mm fan draws only 0.85W.

Or, along the same lines, wire up a 5v relay to the console's 5v power supply and then use that to switch a 12v fan. You get a bit more control over the speed there since then you can use a potentiometer or low-noise adapters to control the speed (I'm not sure the 5v fans support controlling RPM by lowering voltage, though there's PWM versions). Though some of the 5v fans are so quiet that this may not be worth it.

[fwannmacher]

I don't like the idea of having the fans on all the time or all the fans on at the same time due to power consumption :-/

[Guspaz]

Is it a meaningful amount, though? The Xbox Series S/X use 10-13 watts in standby mode, the PS5 is 5-7 watts, though both consoles do have lower power standby modes (off by default). A Noctua NF-A14 ULN only draws 0.36 watts at full speed (800 RPM) while being essentially silent (11.9 dBA).

In any event, my other ideas only result in fans on when their respective consoles are turned on. It may require some soldering, however, and some older consoles don't draw much power, so adding load to their power supplies may not be ideal. 5V relays draw less power than fans.

Another idea is to reduce power consumption more by using the 5v power to feed a GPIO pin on a pi or arduino and have that control the fan(s). This opens up some non-soldering options, for example using the second controller port on a console to get 5V and having the arduino turn the fan on when that pin goes high. Or if not the controller port, you can get 5V from the AV port or the expansion port, depending on the consoles.

Another idea is to adhere to a rule of only turning on one console at a time and then using the headers on an auto-switching SCART switch to control the fans. For example, connect a pi or arduino to a gscartsw's EXT header and this will tell you which input is currently active, which means that console is on, and you can then turn on the appropriate fan. This may actually also require some soldering, as I believe superg stopped soldering actual pins to the EXT header at some point. It's still there, just unpopulated.

[fwannmacher]

I didn't know that the power consumption was so low. Maybe I'll have them always on

Thanks a lot for the tips

[Guspaz]

I would caution to look it up, as the power consumption depends on the type of fan and the RPM. Their IndustrialPPC fans can draw 4+ watts. In Noctua's case, the power consumption at max RPM can be found in the specifications.

Ultimately it might be simplest to just get some quiet ones and run them all the time, and/or have a power switch that you can use to turn all the fans on/off at the same time and just turn them on when the consoles are in use.

The 5V fans are convenient to power (since they can be powered by a USB adapter, which some include), but can only be controlled via PWM, which means you'd need a PWM controller. The 12V fans can be controlled just via a potentiometer that adjusts the voltage. If you don't want to control speeds, one of their ULN fans or a regular fan with included "low noise adapter" and "ultra low noise adapter" (which reduce the voltage by fixed amounts) might get you to the noise levels you want.

There are, of course, other fan vendors than Noctua, who are a rather premium brand (so they cost a lot). Arctic makes some good fans at really cheap prices if you buy a five-pack, so you could get some of those and run them through a pot to cut the RPM. They're like a third the cost of Noctua fans, though the performance isn't quite as good either.

[fwannmacher]

For sure I have a ton of stuff to dig into. Thanks mate!

[RottenToTheGore]

What about some kind of temperature sensor to kick on as needed?

[Guspaz]

You could do that with an arduino or pi, yeah, or companies like Coolerguys make kits meant for home theatre cabinets that have both the fans, grills, and thermal control units.

Also, as a random note, when you're putting holes in the cabinets for fans, remember that fans need both intake and exhaust to work. At a fixed RPM, the higher the static pressure (amount of force needed to move the air), the lower the airflow. If you cut a hole in a sealed box and put a fan in the hole, it will move no air, because the static pressure is infinite. So if you're going to cut a 120mm hole to put a fan in, be sure to cut another 120mm hole on the other side to let the air move.

[fwannmacher]

What do you think would be better: a fan or a blower? Something like this https://www.ebay.com/itm/174741798076?h ... SwsTxXkKkB

[fwannmacher]

Each compartment would look like this with the blower



The back side would have a 2cm opening in the bottom for the cables and the blower would have an air duct to the back. WDYT?

[Guspaz]

Blowers are usually much louder than fans for an equivalent amount of air moved, but can have much higher static pressure. I wouldn't use it for something like this if you care about noise. For performance you can compare them by looking at the static pressure and airflow, though the ability to compare directly is difficult without the actual pressure vs airflow graph.