How to add a fan to a mask.

      How to add a fan to a mask.

      So I thought I'd share my experience of adding a small fan to my mask in case anyone else wants to try it.

      The main reason I did it, was because I'm using sunglasses lenses for eyes, and they fog up like mad unless you do something like this, but it also feels nice, and makes breathing, one of my favorite things, much easier.

      Here is the outside view of the mask:



      You can see I've added foam spacers to add an air gap between the mask and the wig, this is so the wig doesn't block the flow of air out of the mask (It's an exhaust fan).

      Post was edited 2 times, last by “gailblue” ().

      Here's a close up of the fan itself:

      (The mask was originally passively cooled, which is why I've taped over all those holes. You don't want the fan intaking air from the top where it will do no good.)

      An obvious concern is the noise. The fan itself only generates 18 decibels of noise, but the bigger concern is the noise of rushing air as it escapes from a hard plastic hole. While it is a pleasant white noise, it can make soft noises hard to hear (It's about like having an ac unit turned on about 10 feet away.)

      The blue fabric diffuses some of that air noise, but a better solution would be to cut a square hole and mount the fan flush with the top of the mask.

      If you are looking for quiet fans, I'd look at Noctua and Sunon for 5v fans, and SilenX and Noise blocker for 12v fans. The largest fan you can reasonably mount is probably 60mm, but 40mm is the most common size for 5v.

      Post was edited 1 time, last by “gailblue” ().

      Here's an inside view with the battery:


      (The battery gets held in place by velcro along the back of the mask. It weighs about 2oz)

      It's important to get everything running from a 5 volt source, because usb power banks are by far the best batteries for this. This 2300ma credit card power bank holds about 11 watt-hours of juice. The battery consumes about .25 watts, so it should last around 44 hours.

      I originally tried a 12v a23 battery, but that only lasted all of 35 minutes. You could get by on a standard 9v, but then you're probably not getting nearly the full cooling power of the fan (most 12v fans stop spinning at 7v)

      Another option is it get a 5v to 12v step-up (looks like a slightly larger than normal usb plug), which will let you run 12v fans off of a 5v line. This will greatly increase your choice of fans, as 90% of case fans are 12v. The downside is that you'll lose around 12% of the power to the volt conversion, but considering how little juice these fans consume, it's probably worth it.

      Post was edited 5 times, last by “gailblue” ().

      And here's a final shot of the inside of the mask:


      Overall, I'd say it works pretty well. On average, a human exhales about 2.5 cubic feet of air per minute, and this fan can move about 5. It's tiny and except for some white noise, it's pretty easy to forget about.

      I'm in the process of designing a new mask, and I'm going to mount a 60mm 12v fan in that one. That'll let me reach 10 cfm of airflow, which should be plenty, and will cut down the noise considerably. The issue with 60mm fans is that they are usually a lot thicker. My 40mm fan is only 10mm thick, while 60mm fans are almost always 25mm thick.

      60x25mm fans are however a whole lot quieter, silenx makes one that moves 10 cfm of air at a virtually inaudible 8 decibels. I'm going to try to fit that one in, but if I can't, sunon makes a 60x15mm fan that runs 11cfm at 14db, so that's almost as good(but it's not sold in stores so I'll need to order online).

      One final note is that if you want to do this, at some point you're going to have to solder the powerlines from a usb cable to a 3 pin fan connector. It's about the easiest soldering job there is, as I did it just fine with zero experience. But you will need to cut open a usb cable, find the red and black wires, (ignoring the green and white) and attach them to the red and black lines on the fan connector (again ignoring the white wire.)

      Post was edited 3 times, last by “gailblue” ().

      nice! one thing you could do about the noise would be add some electronics. A tiny microcontroller with a thermistor inside the mask and a MOSFET to control the fan wouldn't take much space at all, and you could regulate the fan speed based on temperature, so when it's not too hot (say inside) the fan would idle down to be quieter, and when there's a lot of heat (either you're outside in the sun, or heat is just building up) the fan would speed up to reduce the heat. You might lose a tiny bit of battery to this, but not enough to cause issue. While you're at it, you'd want to add a couple buttons to the setup to allow direct control (have a button that maxes the fan out for a minute to cool off for example).

      Another idea I can think about would be to swap the traditional fan in favor of a blower, and using some ducting to get the airflow exactly where you want it. This could allow you to increase the cooling capability perhaps, but at the cost of airflow and noise. Also IDK if a good size air duct would fit in there very well.

      Good work my friend, keep it up!
      Your signature here
      I like the microcontroller idea. How small can they get? I'd probably try and mount it next to, or inside, the battery. I've been checking out various switches as well, I plan to mount a fan off/on switch behind the ear(or a fan speed controller knob if I can find a small one).

      I was thinking of adding a switch under the chin to activate when I open my mouth widely, but I have no idea what it would control (laser eyes?).

      I did a little more work on my mask, improved the vision to a level where it doesn't feel impeded at all (the whole point of uses lenses). The best lenses I found for that are motorcycle goggles, because they are cheap, not very dark, and just the right size. Also looked into using hard hat suspension instead of padding, It feels too solid for my taste, but if you want to ratchet a mask to your head so it won't budge, and leave most of the inside of the mask open for "extras", that'd be the way to go.
      Having dead airspace inside a mask causes it's own problems.

      Exhaled air builds up in those areas, and eventually there's a CO ( Carbon Monoxide ) buildup as well. That means you need a stronger fan moving more CFM to exhaust the spent breath.

      In my masks I use the other method, where the fan sucks air in from outside and presents it to the nose and mouth for inhalation. Letting the airflow push spent air out along the mask edges. I can't really tell from these pics if your mask's mouth is open or closed. Can you drink through a straw?

      Given your situation with the eye lenses, I would consider building a little ducting inside the mask. Again, the size of a blower is problematical for insertion inside a mask, but a blower that ducts the airflow in and over the inside of the lenses would probably help the fogging problem greatly. (Also helps with condensation caused by outside temperatures fluctuating.) Otherwise you are left with the standard anti lens fogging solutions available. Personally, I find Cat Crap (tm) works, either the paste or liquid versions

      :P Of course the next level solution, would be to install working ducting inside the mask leading to a mouthpiece from a snorkel. As long as the duct is under 12" long, with a cross section equal to an inch diameter,and opens under the hair behind the ears, It will work just like a regular snorkel and provide you with fresh air as well as dumping spent air outside the mask.

      Turn elf ears into snorkels, and you could create a mermaid character.

      Kiki

      gailblue wrote:

      I like the microcontroller idea. How small can they get? I'd probably try and mount it next to, or inside, the battery. I've been checking out various switches as well, I plan to mount a fan off/on switch behind the ear(or a fan speed controller knob if I can find a small one).

      I was thinking of adding a switch under the chin to activate when I open my mouth widely, but I have no idea what it would control (laser eyes?).

      I did a little more work on my mask, improved the vision to a level where it doesn't feel impeded at all (the whole point of uses lenses). The best lenses I found for that are motorcycle goggles, because they are cheap, not very dark, and just the right size. Also looked into using hard hat suspension instead of padding, It feels too solid for my taste, but if you want to ratchet a mask to your head so it won't budge, and leave most of the inside of the mask open for "extras", that'd be the way to go.


      How small can you go? If you want an easy solution, then look no further than an Arduino Nano. They're fairly small (44x16x7mm from what I just measured), and have everything you need on one board - no external voltage regs, clock crystals or such needed. The best part is you can get generic ones (which work just fine) off ebay for $2-3 each, and better yet is you program them over USB so you don't have to buy anything else.
      If you want smaller, you can get the ATTiny85 (which is an AVR chip just like the micro in an Arduino board) which is the size of an 8-pin DIP - about 10x9x7mm. To program that, you'll need another Arduino board however. There are other options, most notably PIC micros, but those have a bit more barrier to entry than the AVR/Arduino world. You also need room for a MOSFET, about 10x25x5mm depending on how far you cut down the legs. Thermistors are pretty tiny (just a couple mm circular devices), and you'll put that wherever you want heat measured. Only other thing needed is a resistor for the thermistor circuit - again, of trivial size. If you need help with circuitry/programming, I'll be glad to.

      Also, instead of a hard hat, you could try a baseball cap with the bill removed for something softer.

      EDIT: You'll probably want to model and print a small panel to house the power switch + whatever control buttons you want to add. This shouldnt take too much space, you can get really small buttons/switches (although usability is a concern here).
      Your signature here

      Post was edited 1 time, last by “KineticIsEpic” ().

      Kinetic, you might be the right person to ask about this, so I'm trying to install a 12v fan and run it off of a 5v usb powerbank. I've got a little 5v to 12v step up, and I was thinking about adding a fan speed controller after that.

      But... I assume a fan speed controller is just an adjustable step down. I doesn't make much sense to put a step down directly after a step up, so I was trying to find an adjustable step up.

      I found a good one on alixpress that takes 5v in and has a range of 5v to 12v, so I wouldn't have to worry about frying my fan,(or more importantly my head!) But it uses a tiny little screw for adjusting. I'm looking for a step up module I could adjust with a knob if you happen to know of such a thing.
      Optimally, you find a battery with output at or near 12v - this will drive everything without the need of regulators (since the Arduino has one already) or boost converters. Otherwise, don't take this for granted as I'm no electronics engineer, but putting the boost converter before your mosfet should work just fine, especially since power efficiency isn't a huge concern here.

      Variable speed controllers like that won't work because they use a physical hardware speed control (the little potentiometer you turn with a screwdriver), and would take a lot of modding to make them controllable electronically. Just a simple mosfet (or even bipolar transistor, it's a low current situation) is probably a better choice than complicated circuitry.
      Your signature here
      Sounds like an potentially interesting idea for a robot/android cosplay.
      Said mask could have computer like vents and the whir of the fan could be a nice effect which adds to the general implication of mechanical parts inside.
      Regardless, it sounds like a brilliant way of keeping temperature regulated. Although i'm somewhat curious as to how much efficiency is lost due to a wig.