Using a radiator or cooler is a good way to simulate actual use resistance. Adding a filter test as well on the front of fan is good too. But using tapered adapters to 80mm, cotton & steelwool will be way more resistance than actual use .. at least my normal use. For accurate repeatable results the best way for most of us to test fans is use a cooler or radiator and record CPU heat rather than CFM. Equipment to accurately monitor CFM and mm H2O is extremely expensive.
3/4/15 at 8:38am