I just bought a 120mm fan that does 24-72 CFM. It is mounted onto one of my 5.25 bays and is facing my heatsink. Reason I don't have it mounted directly on heatsink is because heatsink doesn't have a place to mount second fan.
Is this effective at all? I did some temp tests and it dropped from 30celsius to 29celsius on idle. This may be due to change in room temperature though. Is this fan strong enough to even push away through the heatsink at 6inches away?
Put it ON the heatsink, use wireties, tape etc. I don't understand your issues. Post a pic please.
I tried attaching it to the heatsink via zip ties, but I am unable to get a good hold on it since the heatsink itself wasn't made for two fans. The side Im trying to attach to doesn't have any place to attach the zip ties to.
What hs is it? I have an extra 80mm fan mounted on a card template on top of the stock cpu fan, Its superglued but if you hs has them mounted on the side or something, might not work as well.. post pics
As mentioned, the fan will only directly draw heat from the heat sink if it's right on it. However, case fans = reduced case heat = lower heat sink temps so I mean, it does help but only passively... and only if your case isn't already very well cooled. You should try posting a pic or give us the heat sink spec so we have a good idea what you're talking about, might be able to help.