Fan size adapters

[Lithan]

Hey, I was wondering about these 80mm to 60mm and 120mm to 80mm fan adapters. Are they effective? Do they inhibit the fans airflow significantly? Id there any reason not to use one if you've got room?

 

[Jkasmann]

The impression i get from people is they are better used when trying to reduce noise, ie getting reasonable airflow from a nearly silent fan. Seems like for highest performance the 80mm high output are better than a high output adapted 120mm. Could be wrong about this though...

 

[markst1]

I use an 80mm-120mm adapter drilled to mate to a 70mm heatsink along with an 84CFM 120mm fan. The adapter seems to reduce the flow about a third. So multiply the stated CFM by 0.67 and that's about what you can expect in airflow rate. Lots quieter than the usual noisy 70mm screamers and slightly better cooling...Mark

 

[lazerin]

When using an adapter, try to get an adapter that is fairly tall. The reasoning behind this is that with a short adapter (eg the distance between the to fan is short), the sides will have a steeper gradient causing the air to bounce of the walls and create large amounts of turbulence that slow the airflow. With a tall adapter (bigger distance between the fans) the sides are more parallel and the air will not rebound off them irradically and cause turbulence. Instead, the air will be smoothly directed down to the bottom of the adapter with virtually no loss of pressure.

In fact, the air coming out the small opening of the adapter will be COOLER than when it entered at the top. This has to do with physics which I won't explain here. This point is often overlooked when asked about adapters.

 

[ziah]

i have a volcano 7 and my finger removed 2 blades OUCH!!!!

anyway im going to be watercooling in the future so i was thinking of mating a 120mm fan to the volcano and just use it as my radiator fan when the day comes. or upgrading to a TT smart fan II. any opinions?

quiet is always better for me.

~z

 

[Lithan]

Lazerin, is that cooling related to the pressure compressing the air? Im no physics major, but would that effect even be noticable. Also thanks for the tip. Hopefully now I can find a nice tall adapter or maybe try to make my own adapter as I can only find one cheapy, plastic, short as hell, one in 80 to 120mm.

 

[lazerin]

Lazerin, is that cooling related to the pressure compressing the air? Im no physics major, but would that effect even be noticable. Also thanks for the tip. Hopefully now I can find a nice tall adapter or maybe try to make my own adapter as I can only find one cheapy, plastic, short as hell, one in 80 to 120mm.

Yup, it sure is. If I remember correctly, its Boyle's law relating pressure to temperature.

No probs on the tip