SPACE BUCKETS

This is my filter prototype! I used Corsair SP120 static pressure fans. There's quite a bit of info on what stacking fans does and doesn't do. The simple summary is stacking fans doesn't increase airflow (CFM) but does increase ability to overcome any resistance in air flow (Static Pressure). Static Pressure fans are designed specifically with this in mind and have tighter clearances around the blades and most obvious, the blades are wider and overlap each other. This gives air less a chance to leak back or not move as the blades pass by. I fully wouldn't expect this to work with regular PC fans. They just don't have enough ability to overcome static pressure created by a filter.