This is fan assembly iteration 2. The first iteration can be seen in a prior post. I have been working on this assembly for months, trying to find a 120 mm fan that works (literally), is powerful enough to blow air through a HEPA filter, and has a connection for a power outlet. Most 120 mm fans have connections for computer interiors and require adapters for direct connection to power outlets. After ordering a few fans, I was finally able to connect a high speed pressure fan directly to an outlet using a 12V DC power supply with 4 pin Molex.