Hello, everyone.

I hope that this design reaches many people, so please like, comment, share, and donate to help better it!

Please also see the original posting on Thingiverse: https://www.thingiverse.com/thing:4510665

This device is known as a Powered Air Purifying Respirator, PAPR for short. Its function is to supply filtered low-pressure air to a mask fitted to the face to assist breathing, remove moisture, and reduce the effects of a poorly fitting or sealing mask while protecting the user from airborne particles ranging from mold, dust, pollen, or even bacteria and viruses.

The reason for this device being made was originally from a college class group project in which the goal was to rapid design and prototype a new design that could be used to fight COVID-19. With this said, I would like to thank my teammates Jacob, Chan, and Bradley for their time and assistance with the papers and presentations leading to this point.

When used properly and with the appropriate filter material, this device is capable of providing filtered air for over 12 hours at an upfront cost of around 30 dollars total excluding the battery, filter material, or mask. It uses no special filters or fasteners and can be adapted to a wide range of DC power solutions and existing masks through the use of a universal CPAP tube.

To make this PAPR, you will need :

Two 5015 Blower Fans:https://www.amazon.com/SoundOriginal-0-10A-0-15A-Humidifier-Aromatherapy-Replacement/dp/B071WMHNG5/ref=sr_1_3?dchild=1&keywords=12v+5015+blower&qid=1593470320&sr=8-3

One DC-DC Step-Down Buck Converter:https://www.amazon.com/Converter-Module-LM2596-3-2v-35v-1-25V-30V/dp/B07SSTTRHJ/ref=sr_1_21?crid=2AKJULSG5HA3A&dchild=1&keywords=buck+converter&qid=1593470212&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sprefix=buck+conver%2Caps%2C226&sr=8-21

Two Male Spade Connectors: These usually come cheaply in terminal sets. Use either #16-14 AWG or #22-16 AWG
https://www.amazon.com/Haisstronica-Connectors-Electrical-Connectors-Quick-Disconnect-Electronics/dp/B07RT4RSGJ/ref=sr_1_4?crid=1ITOE4TVUUS8U&dchild=1&keywords=male+spade+connectors+22-16+awg&qid=1594746242&sprefix=male+spade+conne%2Caps%2C167&sr=8-4

5.25" x 5.25" of Filter Media: NOTE. The filter media is critical for this device to function properly. In order to remove COVID particles from the airstream, a filter with a MERV-13 or higher rating is recommended. This device currently uses a MERV filter and filters the air twice for maximum particulate removal efficiency while still retaining an effective pressure.This MERV-13 media may be cheaply obtained by utilizing a MERV-13 rated furnace/AC filter and cutting out the material you need from it. If this is used, ensure that the media does not used glass fibers because they may become dislodged when cut which could cause injury to the user if inhaled or rubbed against the skin.
https://www.amazon.com/Accumulair-Diamond-12x24x1-11-75x23-75-Furnace/dp/B008O56KJS/ref=sr_1_5?crid=200RRAHOMH2FW&dchild=1&keywords=merv+13+air+filter&qid=1593471481&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sprefix=MARV-13+%2Caps%2C167&sr=8-5

One Black and Decker 20V Max Lithium Battery and Charger: Currently, this design only has an adapter for this battery, but if it is well accepted and supported with likes, comments, and donations, more adapters can and will be made to allow greater connectivity.
https://www.amazon.com/Replace-Battery-Lithium-Ion-LBXR2020-OPE-Cordless/dp/B072191NQJ/ref=sr_1_7?crid=8GNZN1YZ5NE7&dchild=1&keywords=black+and+decker+20v+lithium+battery&qid=1593471680&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sprefix=black+and+%2Caps%2C180&sr=8-7
https://www.amazon.com/Replcaement-Battery-Charger-Lithium-WA3512-1/dp/B07VPNDXRF/ref=sr_1_2?crid=1KSTDZP9ZOOCG&dchild=1&keywords=black+and+decker+20v+lithium+battery+charger&qid=1593471852&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sprefix=black+and+decker+20v+lithium+battery+%2Caps%2C186&sr=8-2

3-4" of Wire: For this device, solid core copper wire was used, but generally, any wire can be used as long as it is above 20 AWG and can be effectively crimped in the terminal connectors used.https://www.amazon.com/s?k=solid+core+copper+wire+20+gauge&crid=2CFZQN2L6V24C&sprefix=solid+core+copper+wire%2Caps%2C175&ref=nb_sb_ss_i_3_22

Sealant/Solder: For this device, hot glue was used to affix the fans, buck converter, and seal the battery adapter in place, while solder connected the wires to the terminals and buck converter, but pretty much any adhesive can be used. Just don't use a sealant/adhesive which drastically degrades over time or offgasses.

How to make this PAPR:

1. Review all posted GIFs, photos, and attached files.
2. Obtain all necessary materials listed previously above.
3. Print all STL files posted above (Housing, Larger Gasket, Smaller Gasket, Lid, Locking Key, and Battery Mount). NOTE: The Lid will require support material.
4. Roughly assemble all the pieces and test fit, deburring as necessary for a smooth but tight fitment, and then disassemble.
   1. Slide the Battery Mount onto the Housing
   2. Slide the Lid down onto the Housing through the grooves
   3. Slide the Locking Key into the housing
5. Mock up the location of the 5015 blowers and buck converter in the housing and measure and cut the wires to the appropriate lengths for fitment. NOTE: Be mindful of the positive and negative wires and the in and out of the buck converter. Out goes to the fans and in goes towards the battery pack.
6. Measure the length of wire needed to go to the battery pack and cut. NOTE: The wires will need to be separated and go to positive and negative respectively, so test fitting with the battery, terminal connectors, and the Battery adapter on the Housing may be necessary
7. Solder/ adhere all wires and terminals. Starting with the wire terminals, work towards the fans last. Crimp the terminals onto the wires and feed the wires through the Battery Adapter on and into the Housing. From there, then solder/adhere the positive and negative "in" wires from the terminal connectors to the "in" on the buck converter. Next, solder/adhere the wires from the fans to the positive and negative "out" on the buck converter respectively. Finally, adhere the fans to the housing after firmly inserting them through the wall of the housing, followed up by the buck converter. NOTE: Once done, make sure all gaps in the walls of the housing are sealed up to prevent any leaks.
8. Test with the battery slid down on the adapter to ensure proper function. NOTE: Obtain a voltmeter and make sure that the buck converter is running at a measured "out" voltage of 12v or the rating of the blower fan used. This is critical as it affects the noise and life of the fans.
9. Once running properly, use the Lid as a stencil placed onto the filter media and cut around it with scissors or a knife to form the filter patch. NOTE: Leave a little extra on the bottom (maybe .25" or more) for gasket clearance.
10. Place the filter patch over the Housing and use the Smaller and Larger Gaskets to press the patch into the grooves of the Housing, leaving them in place.
11. Applying firm pressure, slide the lid back onto the housing and secure it by inserting the Locking Key into the Housing.
    12: To use the completed PAPR, slide a fully charged battery on the Battery Adapter
12. Attach to a CPAP tube and mask or request an adaptor to an existing 3Dprintable mask and enjoy the filtration.

Follow Up:

Please post comments and questions. They are vital to developing this design. Donations are greatly appreciated and will be used to further support this device.

Be safe, be conscious, and remember... This device has not been certified or professionally tested, so use at your own risk.

Thank you.