Helmet Fans, Ducting, & Padding

Elcorio

Active Member
Hello All,

First and foremost, I apologize if this is either the incorrect forum to post this in or has already been addressed. Admins & Moderators, please move or delete if this is the case.

I searched the forums and couldn't find any other threads that did what I did for my ODST helmet, so I thought I would create a thread documenting what I felt to be something uniquely done (maybe?)

While I know the use of fans inside of helmets has been around for quite some time, I didn't want to simply throw some fans inside the helmet and call it a day. I wanted to direct the airflow to or from specific areas within the helmet and this is what I came up with.

The idea was to create a duct system where the fans could either push cool air in from the outside OR exhaust it out from the inside.

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I opted for a push / pull set up using three 5V fans. The first up was a single 5V fan mounted in the chin area of the helmet. A box was made around the fan using 5mm foam and cut at an angle to allow the air to blow just above my chin. Using the sculpted lines on the exterior of the ODST helmet, I cut through the little chin "bubble" area just wide enough to allow the fan to "pull" air from the outside.

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Using computer fan filter mesh, I created a "grill" and contact cemented that on the inside of the helmet. A little bit of paint to clean up the cutting wheel marks and the chin grill is almost unnoticeable from the outside. Velcro hook sides were then applied on the inside of the chin area and smaller loop strips were cut and placed on the fan housing. All velcro was secured using contact cement as an adhesive.

With the push fan installed, it was now time to work through the ducting work for the pull phase. The fans used for this were 5V blower type fans and those had a hugely significant CFM (Cubic Feet / Minute) rating. Several locations within the ODST helmet were looked at, but I found that the lower rear of the helmet provided the most room when wearing it to mount the fans.

The first duct built was done using a single fan and I used 5mm foam for the whole thing. A spacer was needed between the fans side intake and this was initially done using foam. However, several issues became apparent with this design. First, the width and height of the duct's intake was too small and the fan had to really work to pull the air through the duct. Secondly, the foam spacer tended to want to collapse in trying to "bend" the duct into the curved shape of the helmet. Lastly, with the width and square nature of the duct, any bending of it caused it to collapse inward, thus blocking air flow.

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The collapsing issue was easily solved by adding interior "ribs" to duct, but it also further restricted the airflow. The sidewall height of the ducting was then increased using 3/8" foam and this seemed to be the perfect size for allow enough space for airflow without sacrificing the rigidity to prevent interior collapsing.

Next came the fan's side intake spacer. 2" PVC tubing had an identical O.D. (outer diameter) as the fan's housing and was measured at the same height (3/8") and cut. A piece of it was then cut out to create the intake channel and solved the crushing issues associated with bending the ducting and putting undue pressure on the actual housing. Finally, a top cover was made thus sealing the whole thing together.

With the addition of the internal rib supports, the single duct could now be shaped into any curve desired and at certain lengths, could even wrap around on itself without any collapsing issues.

Not really favoring the single duct set up, I decided on pairing the fans side by side and created a dual duct system using the lessons I had learned from trial and error.

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The ducting was built larger than needed in length and width to allow me the option to cut it down as needed once I was ready to mount it inside the helmet.

All three fans were then connected to a USB cable which then ran to a 10,000 Mah Dual USB solar portable external battery pack. A stress test was done to test how long the battery bank would push all three fans. 8.5 hours of non-stop use was recorded! The fans were connected to the battery bank (at full charge) and left to run all day sitting next to me at work.

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So how did it compare when wearing the helmet? The airflow was INCREDIBLE! The chin mounted fan was just enough air to keep the visor from fogging up without pushing a ton of air into my face. The rear exhausting fans effectively pulled any warm air out and dispersed out the back of the helmet. To be honest, the cool air hitting my neck and traveling down my back felt good as well. On top of all this, I had a balaclava on as well and had no issues with heat or fogging.

Now came the helmet padding issue. Again, I searched far and wide for ideas and even tried a few, but none seemed to fit the bill for what I wanted. Using a hard hat suspension system as a guide, I designed a head band using 1/2" foam and incorporated velcro into it to make it adjustable. A 4 point system was then designed with the center sitting on top of my head and the four "arms" connecting to the headband. A top piece was added with bevels cut in to it to serve two purposes. The first was to allow it to contour to the curve of the helmet and the second was to create channels for added airflow. Velcro was added to all connecting points, thus allowing a truly modular system for customization.

Then aluminum strips were added to give the "arms" a bit if rigidity without being overly heavy or in the way. Everything was put together using contact cement except for the fan to PVC adapter ring. I used Loctitte epoxy compound for the plastic to plastic connections.

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I certainly apologize for the lengthy post, but in the end, I also hope it may have ignited more creative thoughts or given someone another possibility into people's fan set up when wearing their helmets.
 
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he4thbar

Well-Known Member
This is amazing! I've looked on the forums, and while I see a lot posted about the creation of helmets, usually the smaller parts like fans and padding are left out. Looks great though! I was thinking of getting those same fans for my build so i'm glad to hear they work well. Those duct vents look awesome though! The grills were a nice touch too, reminds me of ventilation for paintball masks (just less)
 

he4thbar

Well-Known Member
This is a paper helmet correct? Did you adjust the scale at all to accommodate for the mount/fans, or did it just work with the space on the seams to what your original plan was?
 

Elcorio

Active Member
This is a paper helmet correct? Did you adjust the scale at all to accommodate for the mount/fans, or did it just work with the space on the seams to what your original plan was?
I did adjust the scale of the pep file for the size I needed. However, my method is a bit off from what the accepted practice is. I used the "measure distance" option and measured the width of the two closest interior points across from each other (basically, ear to ear). I then measured the circumference of my head and divided it by Pi (3.14). I then scaled the helmet until the measured interior point was the same as my divided number. From there, I simply added an inch. In theory, this would give me a 1/2" of space on either side of my head. It worked out for me as I have enough room to get the helmet on and off without looking like a bobble head and at the same time, there is a bit more room for accessories.

On the side grill / cheek pieces, there is plenty of room to incorporate another set of ducted fans pulling air from outside and pushing it up into the helmet, but I figured five fans was a bit overkill if the current set up works fine. This was actually my plan when I cut out the cheek pieces and put the grills in. I also wanted to keep the helmet suspension system as least intrusive as possible. The first pic in my thread shows that it is starting to get a bit crowded, but the helmet wears just fine without feeling claustrophobic.
 

he4thbar

Well-Known Member
I did adjust the scale of the pep file for the size I needed. However, my method is a bit off from what the accepted practice is. I used the "measure distance" option and measured the width of the two closest interior points across from each other (basically, ear to ear). I then measured the circumference of my head and divided it by Pi (3.14). I then scaled the helmet until the measured interior point was the same as my divided number. From there, I simply added an inch. In theory, this would give me a 1/2" of space on either side of my head. It worked out for me as I have enough room to get the helmet on and off without looking like a bobble head and at the same time, there is a bit more room for accessories.

On the side grill / cheek pieces, there is plenty of room to incorporate another set of ducted fans pulling air from outside and pushing it up into the helmet, but I figured five fans was a bit overkill if the current set up works fine. This was actually my plan when I cut out the cheek pieces and put the grills in. I also wanted to keep the helmet suspension system as least intrusive as possible. The first pic in my thread shows that it is starting to get a bit crowded, but the helmet wears just fine without feeling claustrophobic.
This is all great information thank you, I gotta wonder how loud those fans would be that close to your head, but i'll learn that once I have them. thanks for the info, and thanks Sean Anwalt for the standard helmet building info. very happy with how responsive everyone is on here.
 

Elcorio

Active Member
I gotta wonder how loud those fans would be that close to your head,
Its not quiet by a long shot, but by keeping the higher CFM fans at the rear bottom of the helmet and the slower spinning one at the chin, they are as far from my ears as possible. There is just a steady hum to them, but I believe that the foam acts like a vibration damper. I can hear just fine without the whining noises from the fans not being right near my ears and there is absolutely no vibration whatsoever due to the foam mounting solution. At least that's my theory and I'm sticking to it! LOL.

Next time I fire them up, I'll throw my cell phone in there with a decibel meter running to see what the decibel level equates to.
 

Elcorio

Active Member
Wanted to toss out a little update on how effective the fans & ducting are. I purchased a voice amplifier and mounted the mic into the helmet as well and wanted to take the whole set up out for a test run before the con this weekend. Last night, I connected the power source, threw it in my pocket and proceeded to take care of the kids and dishes while rocking the ODST helmet. The kids thought it was just the funniest thing hearing dad sound like Darth Vader and naturally, the "Ethan, I am your father" had to be done!

In between the fans and the power supply, I threw in a rocker switch and ran it with enough wire length to mount on the inside of the chest piece. Each individual component can be replaced if needed due to JST connectors being used throughout the wiring harness. I turned the fans off and really let the visor fog up inside. Like, could barely see where I was walking fogged up. Hit the switch, and within a minute or so, it was clear as day again. The chin mounted fan angled upwards pushed the warmer air up and back where the ducted higher cfm blower fans were able to "grab" the air and evacuate it out of the helmet. Even spoke with the wife on the phone (speakerphone) while the fans were running and had no trouble hearing her.

Definitely pleased with this set up and will update more after the con this weekend and under longer usage.
 

Elcorio

Active Member
Hello all. Wanted to do a little follow up to this thread in regards to how the system worked in actual use. With the current configuration (intake / exhaust), I was able to keep the helmet on for about 45 minutes at a time continuously without any worries. Once the crowd started to get a bit more dense, the inside of the helmet started to warm up and I could feel the beads of sweat starting to form. Power supply was not an issue and even with the fans on, I was able to hear fairly well, but had to slightly lean in towards the persone as they were talking. With that being said, I did cut out the small square-ish area at the back of the visor about where my ears were and placed computer mesh filter over it.

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Fogging issues were non-existent as well.

IMO, I don't believe the exhausting fans w/ ducting were able to "grab" as much warm air inside the helmet as I would have preferred. So I believe I will revisit the dual blower fan set up and redesign the ducting to be an intake set up versus an exhausting one. Figuring that more cool air pulled in and going towards the top of the helmet will force warm air out through the neck opening.

I'll keep this thread updated as I get to that point, but right now I have two other builds that I am working on and want to get those finished before jumping back to my ODST armor and making learned / discovered improvements.
 

TurboCharizard

Division PR, RMO and BCO
Division Staff
405th Regiment Officer
Community Staff
IMO, I don't believe the exhausting fans w/ ducting were able to "grab" as much warm air inside the helmet as I would have preferred. So I believe I will revisit the dual blower fan set up and redesign the ducting to be an intake set up versus an exhausting one. Figuring that more cool air pulled in and going towards the top of the helmet will force warm air out through the neck opening.
This is pretty much what I've found in practice as well. Unless there's an outlet fan directly at your nose and mouth there's not too noticeable a change in temperature and humidity overall. Having two fans pointed at your face keeping air moving will usually be more comfortable in the long run.
 

RandomRanger

Armory Assistant
Community Staff
So is the lesson here to point the fans directly at my face/visor, and pull cold air in rather than push hot air out? Heat hasn't bothered me too much yet, what concerns me more is not being able to see out of my visor, and condensation building up on my various circuitboards and such on the inside.
 
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