SPCR

Hello,
I'm looking to replace the 70mm fan ontop of my cpu heatsink.
However, as 70mm is a less common size, my choices are limited.
I've read only a little about fan size adapters, but I'm not sure if they are good or not.

Do they work?
Is there anything to watch out for or to expect when using one?
Do you recommend them?

All help is greatly appreciated.
Thanks,
-Daniel

I put a fan adapter on my parents CPU so it can use an 80mm fan. It doesn't seem to make any extra noise. The system is a Pentium III 1GHz and it's very cool and quiet. They may be old, but those are sweet processors. It's on a dually motherboard so I plan to add another CPU soon.

In my situation, it makes sense I think to use the adapter. In your case it seems perfectly fine as well. There may be a space issue, it's pretty close in my parents' case.

From my experience, blowing air through a fan adapter doesn't affect noise at all. I would guess you would get slightly less airflow. Sucking air through a fan adapter, on the other hand adds a lot of noise. As does anything blocking the intake side of a fan.

I voted sometimes.

In your case it will probably work. There won't be a problem with back pressure, since the small side off the adapter doesn't have a hub blocking flow (like a fan has). It is probably even beneficial for noise. Because the fan is slightly further removed from the heatsink there is less turbulence. But in a low airflow situation this is rather academic. You probably won't hear the difference.

If you try things like putting a 120mm fan on a 80mm opening, then you are creating so much back pressure and (probably) turbulence that it is not worth it.

I've used 70-80mm and 70-120mm adapters on ASUS CT-479's. In both cases, I could use quieter, undevolted fans with a substantial reduction in noise and somewhat improved cooling.