Night_Gryphon's fursuit head fan quick HOWTO

This HOWTO is based on my experience and in most cases is IMHO. My heads are plastic masks so some advices are applicably mostly for this types of heads with hard base.

1. General idea

2. Choosing fan.

Key fan characteristics that can be interesting for our task is:

• type: radial or axial.
  Axial fan suck air from the front and blow outh through back. It is the most common type of fan.
  Radial fan suck air from the front and blow out from side. Mostly used as ear fans and such.
  
  Typically when installing fan in to fursuit head nose you'll need axial type of fan.
  
• size
  Try to use maximum size fan that fits well in to your head.
  Larger diameter = more airflow and less noise.
  More thickness = more airflow.
  
• voltage
  Typically for small fans it is 5v DC or 12v DC. Further description is for 12v fan but using 5v is quite similar.
• number of wires
  Typically can be 2 or 3. Both are usable. For 3 wire fan yellow wire is not used.
• bearing type: ball or sleeve
  Sleeve bearing is more quiet. Yes, sleeve bearing have less MTBF so it is less reliable in 24 x 7 x 365 usage. But fursuit is not the case of such intensive usage so most likely you'll not find any difference in reliability.
• power consumption, btu, rpm
  Usually the more rpm / power consumption the more airflow you get.
  More power means shorter battery life.
  More rpm = more airflow but also more noise. Choose something in the middle.

3. Installing fan in to the head

Plan an airflow in head:

• Find the way to suck enough fresh air in to your head. For my heads using nostrils is quite enough but you can need more.
• Remove unnecessary barriers in front of your face so fresh air can freely reach your face through head. For example you can cut unused pieces of plastic eye sphere that is not visible or such (this also will help against eye fogging).
• The best is to isolate fresh air side of fan from used hot air so fan will provide fresh air instead of just mixing air inside head.

I typically build foam "wall" that separate fresh and used air areas and also holds fan. When finished this wall look more like foam frame for fan.

Try to keep fan from direct contact with hard parts of head internals and from head base. Putting fan in to foam frame helps to reduce passing vibrations from fan to overall head and reduce noise.

To hold fan cut a hole in foam wall by shape of fan but a bit smaller than fan. Fan should sit tight enough to not fall out. Do not glue fan to foam so it will be removable. Removable fan allow to clean head, replace fan, enhance airflow when you don't need fan.

4. Cables, connectors etc

Plan cable trace. Fix fan cable.

• Fan cable should not move in random parts of head while you are suiting.
  
• Fan cable should not pass through points where suit head rest on your head as in this points it can squeeze.
  
• Fan cable should not dangle in front of your eyes
  
• It is good to still make fan cable removeable/renstallable easy enough so you can easily remove/insert fan.
  

Plan connectors position if you need them.

• Mechanical load on wires near the connector and connector itself must be as less as possible so it will not disconnect or break at random moments.
• Use connectors with enough fixation or with latch.
• If connector does not have flexible cable holder ending then make it with glue gun over attached wires. This will protect wires from broke near the connector as it is common point of failure.
• Try to plan connectors easy accessible so you can connect/disconnect them in your fur gloves. I'm too lazy to take suit off just bacause i forget to connect that connector ;)
• Use female side of connector for power supply side of cirquit and male side (with pins) for load. This will help to protect from accidentally short cirquit your power supply/battery.

Plan battery position.

• Find unused space in head or on body to put batteries.
• Try to find more-less dry place.
• Try to put batteries closer to the load to reduce wiring and eliminate unnecessary connectors.
• Keep in mind that you need to access batteries to replace them.

Choose switch type and switch position

4. Electronics

Choose battery.

• Use safe enough batteries that will not fire or explode just because of a bit of sweat happens.
• Choose battery set with voltage not less than load voltage. But don't make voltage too much higher as this will just waste power on voltage down conversion and produce heat.
• Use only same type of batteries in set.
• Try to minimise number of batteries in set.
• Try to find your balance between battery capacity and size. Keep in mind that you also may need battery holder for that battery. I prefer to use battery box instead of just connector to prevent battery from accidentantly disconnect.

My choice for 12v fan is 2 x 9v batteries. They are quite compact and lasts long enough for me.
For 12v fan you can also use only one 9v battery. 12v fan _typically_ works at 9v but produce less airflow but still strong enough to get good results. Also produce less noise at 9v.
For two batteries you'll get better airflow but it's a bit more complex to make.
I prefer two batteries system.

To power up 12v fan i connect 2 x 9v batteries in series that provide 18v for battery pack. Then i use 12v voltage regulator to convert 18v to 12v (LM7812). You can see it attached to the back side of battery box. Resulting schematics is

5. Enchancements

• use impulse DC-DC converter to increase effectivity.
• speed control and thermo speed control to reduce noise and increase battery life.
• airflow organizers/air channels
• other types of batteries
• more fans
• etc.

6. Credits

Regards
Night_Gryphon
gryphon@night-gryphon.ru