DIY Air Outlet Tests Monday July 15th, 2013Thursday October 6th, 2016 Thomas Talhelm Research, Tests Here’s Test 1: Is the air that’s coming out of the filter clean? Is the HEPA trustworthy? See the filter in action. This settles that the air is coming out clean. But is that enough to actually clean the room air? See the room test data and how it compares to the Ferrari filters.