HEPA Positive Pressure Hood 5v blower for bag or mask

thingiverse

https://www.thingiverse.com/thing:4235572 github https://github.com/PhilMo6/HEPA-Positive-Pressure-Hood This is a HEPA filter made with a 5 or 12-volt blower fan and an 86889 HEPA vacuum filter. It is designed to be used with either a 3M half-face respirator, a gas mask with 40mm threading, or any large clear plastic bag to be used as a full-head positive pressure hood. I designed this for myself and anyone else who works in healthcare and may not have access to enough equipment to protect themselves. With a 2-mil or 3-mil optically clear bag, you should have full-face protection that allows you unrestricted breathing and movement. The bags can be easily and cleanly removed and disposed of with basic precautions. The whole unit can be disassembled and sanitized as needed, or an alcohol solution can be used to sanitize without damaging the motor of the fan. Because it uses a standard CPAP hose, a CPAP ozone-based sanitizing unit could also be used to sanitize if available, though this may cause additional wear on the motor from the ozone. The idea came from an article on one of Wuhan doctors who used a car HEPA filter in a similar fashion. I have not been able to find the article again unfortunately. Airflow for use with a bag is more than enough for what the average human breathes. It does work with masks or respirators as well, but not as effectively and still requires some lung force to draw air through the filter. Parts list: - HEPA filter https://www.amazon.com/gp/product/B07DMCKPGJ - Prefilter https://www.amazon.com/gp/product/B000U204W2 - 5V blower fan https://www.amazon.com/gp/product/B012CL2V3I - 8 M5x10 computer fan screws https://www.amazon.com/gp/product/B07MPB94JG - 6ft CPAP hose https://www.amazon.com/dp/B01N4RGZ80/ref=psdc_8627104011_t3_B07Q87VZ62 - Silicon or glue for sealant I used extra-large clear 2-mil bags. These have shown to be strong and clear enough to read text without much problem. https://www.amazon.com/gp/product/B073W23GDF You can find thicker bags or buy 2-mil in bulk from many suppliers. https://www.uline.com/Grp_3/Poly-Bags-Flat-Open CPAP hose can be cut to length and the cut end sealed into the outlet adapter. If doing this way, wait for sealant to set before continuing. Add sealant around the edge of the fan and put the fan into place. Add sealant around the groove for the outlet adapter and set it in place. Seal around the edge of the fan cover and screw it into place. Add additional sealant to the fan's cord coming out of the case. Let it set for 12 hours, then run the fan for an additional 12 to 24 hours to fully cure the sealant and remove any residual gases or smells from the sealant. You can now set the filter into place and cut and fit a prefilter. Then screw the fan cover into place. For use with a bag, screw the adapter into the bag with the hole for the hose facing outward. Once half-way screwed in, cut around the inner edge, then finish screwing it in. Fit the rubber end of the hose into the adapter. Turn on the fan before putting the bag over your head, then tuck it into the collar of your shirt. The 3M mask adapter consists of two parts: the 3MCoupler and the 3MAngle, which should be glued or siliconed together.