I’m currently waiting to inject liquid culture in the jars I prepped last week and came up on some do-it-yourself flow hood videos. Taking inspiration, I’ve come up with a game plan of my own.
- Wooden box (got used)
- Filter
- Fan
- Hinges to hold in place
- Wood cutter
Formula Used for Fan
Basically, you want to ensure you have enough air to flow through filter, but not disrupt and so you have to look for a fan with the proper “CFM” (cubic feet per minute ) measurement, measuring airflow by the volume of cubic feet per minute the fan is able to move. For this, I found this formula used:
((width of filter x length of filter) / 144) x 100 = how many cfm’s your fan needs
example for my filter in picture above:
14 filter length x 10 filter width = 140
140 / 144 = .972
.972 x 100 = 97.2 minimum cfm
No more than 10%
97.2 x .10 = 9.72
97 + 9.72 = 106.7 max cfm
Final: Fan needs between 97 – 107 cfm
Filter Requirement
After some reading, I went with a HEPA filter that “effectively captures 99.97% of particles as small as 0.3 microns“, purchased on Amazon.