//JLI.space/IndexCooling - Valve Index Cooling Mod

hey, as the index can be used as a nice space heater when not in use and starts grilling your face after an hour of playing VR, I decided that this thing needs some cooling. I'm not a professional cad-modeler. I'm a electrical-engineering student and I just made this for fun.

Also, please excuse the messy print quality. Photos are from a bad Ender 3 print.

This mod uses parts of the Index Hardware CAD files: https://github.com/ValveSoftware/IndexHardware

The fan are fully software controllable so you can adjust the fan speed from within vr without having to search for a knob or having them blast at full speed all the time. I've added three lighting-modes, static color, rgb (of course) and a strobing effect which makes the fans look like they are spinning really slow which looks kinda cool. Not that this is important as you're - most of the time - not looking at it from the outside. :]The space oft he frunk is pretty limited so I decided to replace the whole frunk-panel. That way the fans are completely embedded into the headset and the cabeling is also concealed.I also managed to not obstruct any tracking sensor. The only drawback is that the visor doesn't fit anymore but adding it only makes it heat up faster. As you can see, I went with an fully closed front panel (excluding the fans) so all the air has to pass through the face-gasket area which actually causes a subtle stream of air, cooling your face while playing. It also helps the headset to stay cool as the index easily goes up to ~50°C while not(!) playing and can reach up to ~65°C+ while playing. Enabeling the fans drops the temperature to about 35°C max. (Measured @ 120Hz on the visible IC's on the PCB below the frunk)

The noise of the fans is also not too loud but I'd definitely stay with noctua as other brands seem to ignore the noise level of their fans. (Also, I used their cutout so other brands most likely won't fit.) But as I've said, using the settings, you can alwas find the best speed setting for any type of game. They don't look super nice and they're pretty expensive but quality goes first, I guess.

Stuff that I've used:

• the index cad files (thanks valve c: )
• 3D-Printer (Ender 3 Pro)
• 2x Noctua NF-A4x10 5V PWM
• 1x ESP8266 for controlling
• 2x WS2812B (one per fan) for strobing/lighting
• old USB cables/plugs
• Arduino for programming (+FastLED)
• html/css/js for handling the webinterface
• wallpaper I stole got from https://www.reddit.com/r/ValveIndex/comments/b88pmk/ladies_and_gentlemen_valve_index_wallpaper_4k/ for the settings page
• hot glue for fixing the cables to the print

Some pictures/videos: https://photos.google.com/share/AF1QipMPPgWjj8fU-xwhmOxJG4iGlKGGL2Db1FN-XWi6ey-G1Yt0iWypXncTnwYBVkiyUg?key=R3otU0o4ZFNWcWlXQTQwQ2NOTE9CeU1mYVFpeFJn

Since then, a lot of people have contacted me, wanting to build their own. Additionaly, a few other guys told me that this mod will most definitely kill my headset in the long run. As it keeps getting warmer, I decided that I would finally release it all.

Doesn't kill your headset
After using my headset for the last ~6 years, I'm happy to announce that it still works absolutely fine. Tracking is still spot-on and my lenses/screens also have zero defects.
So if done properly, the mod doesn't damage the hardware at all. I've even had to RMA my whole headset recently due to the camera failing while updating to the new firmware. I guess if you don't f*ck it up, your warrenty won't void. If you do, it will.

Does it even work?
Also, a lot of people asked about the effectiveness of this mod in general. As someone who plays beatsaber a lot, I can say that it does make a huge difference to the comfort while in VR. You can't expect a giant stream of air, but even at 50% it's enough to let you play a lot longer than without it. To some extent, it even stops your face from sweating at all in slower games, preventing your face gasket from getting all soaked up, which is kinda nice. Especially when using >110% brightness and 120-144Hz.

Performance
The two Noctua NF-A4x10 5V PWM which I've been using ever since, have more then enough power for this application. More then you could every expect from for example something so small like in the chilldex. I've tried both (chilldex only for ~2h), and the chilldex has no chance against the small intake provided by the frunk. To be fair, it's a good product for the price, but some diy-ing could result in much greater performance.
If you have a 3D-printer and an Index, it's a no brainer.

3D-File & Arduino-Code
(attached)
Any orientation is fine, but standing upright is easier on the support usage. Use a raft or at least a skirt. I've used cheap PLA, worked great on my Ender 3 Pro.

attached arduino code: valveindex_glow_by_jli_space_V8.ino
When used with a ESP8266 it allows changing the speed/rgb color and effect from within VR using a browser like Chrome. It's most likely not plug-and-play and you'll have to adapt it to your microcontroller/fan setup. I guess it could be a nice starting point.
Obiviously, you could also just use a potentiometer with non-PWM fans and dump the rgb :^)

I hope that this helps. I'd love to see some builds if anyone is still into cooling it.
Have a great day :)

Reddit post for this mod:
new: https://www.reddit.com/r/ValveIndex/comments/cs0z0s/jlispaceindexcooling_yet_another_index_cooling_mod/
old: https://www.reddit.com/r/ValveIndex/comments/hop9yb/diy_coolingmod_for_your_index/

Still works fine today on 11.12.2025