HEPA Positive Pressure Hood 12v blower

thingiverse

5v version https://www.thingiverse.com/thing:4213525 github https://github.com/PhilMo6/HEPA-Positive-Pressure-Hood This is a HEPA filter made with a 5 or 12 volt blower fan and a 86889 HEPA vacuum filter. It is designed to be used with ether 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 health care and may not have access to enough equipment to protect yourself. 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 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 drs 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 then enough for what the average human breathes. It does work with mask or respirators as well but not as effectively and still requires some lung force to draw air though the filter. Parts list -HEPA filter https://www.amazon.com/gp/product/B07DMCKPGJ -prefilter https://www.amazon.com/gp/product/B000U204W2 -12v blower fan https://www.amazon.com/gp/product/B07RMJC9NT -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 show 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 cut end sealed into the outlet adapter. If doing this way then wait for sealent to set before continuing. -Add sealent around edge of the fan and put fan into place. -Add sealant around groove for the outlet adapter and set in place. -Seal around the edge of fan cover and screw into place. -Add additional sealant to the fans cord coming out of case. -Let set for 12 hours then run fan for an additional 12 to 24 hours to fully cure sealant and remove any residual gasses or smells from sealant. -You can now set filter into place and cut and fit a prefilter. then screw fan cover into place. For use with a bag, screw the adapter into bag with hole for the hose facing outward. Once half was screwed in cut around inner edge then finish screwing in. Fit rubber end of hose into adapter. TURN ON FAN before putting bag over head, then tuck into collar of shirt. The 3m mask adapter consists of 2 parts. The 3mCoupler and the 3mAngle, these should be glued or siliconed together.