@@ -30,6 +30,16 @@ In order to scavenge hazardous vapors, fume hoods need laminar flow and adequate
Due to the inherent uncertainty in sealing around the perimeter of the box, it is likely that we will need to implement some kind of active blower control to maintain sufficient aerosol scavenging. Since the exhaust will pass through a safety-critical filter, we should also monitor filter performance online and alert caregivers when replacement is needed. In both cases, we will likely instrument the box with low-cost PCB-mounted differential pressure sensors such as [these models](https://www.amphenol-sensors.com/en/novasensor/pressure-sensors/3161-npa-series) from Amphenol (~$30 each single-lot from Digi-Key and in stock). Again, simulation results should point us to the needed pressure differential range we need to maintain to produce good flow conditions, eliminating the need for airflow sensors.
## BOM thoughts
Blower: [Sanyo San Ace 9BMB24S201](https://www.digikey.com/product-detail/en/sanyo-denki-america-inc/9BMB24S201/1688-1383-ND/6192099), $18.15 qty 1:
Filter: [Bosch HEPA cabin filter model 6055C](https://www.amazon.com/Bosch-6055C-HEPA-Cabin-Filter/dp/B01JYSX028), common (many Toyota/Lexus models 2006-present), unknown specs
Controls: 320 x 240 px TFT LCD, soft buttons, Teensy 4.0, H-bridge driver for fan, etc.
## other efforts
Harvard's GSD is working on a [similar concept](https://www.gsd.harvard.edu/2020/04/gsd-begins-patient-isolation-hood-pih-design-and-fabrication-alongside-ongoing-ppe-efforts/): a disposable folded box and a negative pressure system to reduce aerosol risk.
