Currently I’ve built a pseudo air purifier by attaching five 20”x20”x1” air filters to a 20” box fan. This configuration is used as a cooling system for my rack. (Yes, my middle server is missing its backup power supply. Funding is limited but is on the list to purchase.)
What is everyone else using for cooling solutions?
You could just make a filtered front panel and ensure your airflow is all front to back as well.