Question 80mm fans for supper restrictive rads.

[Austin86]

I have a water cooled sleeper pc that has a modern 360mm rad and two old school 80mm rads. The 360mm is partway chocked of air flow so I kept the two 80mm rads to help with cooling. However the 80mm rads have a extremely high FPI and the fans I have on them lack the static pressure to push air through them.

Would anyone have advise on 80x25mm fans for the rads?. I was thinking of some delta aub fans. Any other less nosy options?

thanks

 

[Eximo]

Always Noctua. Usually the go to for high performance fans where silence/performance is the top priority.

 

[Austin86]

A noctua fan wouldn't be able to push much anything past rad I'm using. Give me a second and I'll post a photo of the reds in question so that you can get an idea of the FPI.

Edit
I couldn't find a image upload option, but I checked the roads, they are 20fpi with less then 1mm between the fins. So most fans likely won't work well with them

 

[rubix_1011]

80mm rads? I haven't seen those around since those really old Pentium 3 and 4 watercooling kits from Swiftech and others in the early 2000's. I know there are some out there you can get specifically for 80mm fans even today, but 120mm has been the smaller standards for quite a long time.

For high FPI fans, you can always run fans in pull config, rather than push.

 

[Eximo]

Most of the old watercooling companies still carry 80mm rads, but yes, usually lower FPI. Even your typical radiator is 16 fins per inch, so 20 isn't a huge leap. Thicker rads tend to drop down to 13 FPI.

Still, if you don't want it to be obnoxious I don't think there is anything better out there for 80mm. Using an industrial fan is just going to result in the noise you are wanting to avoid.

 

[Austin86]

80mm rads? I haven't seen those around since those really old Pentium 3 and 4 watercooling kits from Swiftech and others in the early 2000's. I know there are some out there you can get specifically for 80mm fans even today, but 120mm has been the smaller standards for quite a long time.

For high FPI fans, you can always run fans in pull config, rather than push.

I thought about push pull but id have to cut and resize the tubbing. That normally wouldn’t be a problem however the system in question has no res. And yes the rads are very old and have been in use since my athlon XP system was in the case.

 

[Austin86]

Most of the old watercooling companies still carry 80mm rads, but yes, usually lower FPI. Even your typical radiator is 16 fins per inch, so 20 isn't a huge leap. Thicker rads tend to drop down to 13 FPI.

Still, if you don't want it to be obnoxious I don't think there is anything better out there for 80mm. Using an industrial fan is just going to result in the noise you are wanting to avoid.

I don’t mind a little noise, the fans I have now are 30dba. The rads are only about 30mm thick so they aren’t too thick, but its a old school flat fin and round tube rad with two layers of offset tubes so there is very little room for air to pass though. Here a example of a similar rad

 

[rubix_1011]

Those are designed a bit more like automotive heat exchangers where most PC radiators now feature end tanks for I/O and passing coolant from one side to another.

Performance-PCs.com has quite a selection for those DIY projects where you need just about any radiator size, including some Alphacool ones down to 50mm fan diameter size.

 

[Austin86]

Those are designed a bit more like automotive heat exchangers where most PC radiators now feature end tanks for I/O and passing coolant from one side to another.

Performance-PCs.com has quite a selection for those DIY projects where you need just about any radiator size, including some Alphacool ones down to 50mm fan diameter size.

I had thought about changing the rads, I know there are newer 80mm rads. But once more Id have to drain and refill the loop and with no res its not a fun job. Sadly I don't have room for a res without putting it in a odd ball spot that would not work with the pump placement, atlest not without the extra work of priming the pump. So that becomes a lot of work compared to new fans.

At lest I have one good things going here, my system is not over heating... Yet. The CPU is on the hotter side witch will limit my max OC . If I ever get around to overclocking the system that is.
That is why I wanted to get better fan for the 80s. I know its not much but the little things add up.
I think I 'll try a delta AUB0812HH-PWM and hope it works better when slowed way down.
The nf-a8 seems to have a not too bad static pressure rating witch seems odd for a non industrial noctua fan. So that would be a second option.

If anyone has any other idea I'm all ears.

 

[Austin86]

OK I have not bought a fan yet, but after doing some more looking I think I found the right match, the arctic p8. Oddly every model in the line up have the same static presser rating despite having different RPMs. I'll report back once I get them.

 

[Eximo]

I've used some Arctic fans in the past, can't complain. They were 120mm though. Came with some Arctic AIO GPU coolers.

Oddly, I just recalled that I have used some cheap 120mm Cooler Master fans on an automotive radiator of a gen 2 Prius. But it looks to have similar fin density to PC components.

https://www.1aauto.com/2010-15-toyo...MIpsOu66Lg7AIVi4bACh3JCw_SEAQYAyABEgJ1RfD_BwE

Heck of a pump that Prius one though, so not exactly comparable. Since EK launched their aluminum line I have been sorely tempted to build around some of those things. Dirt cheap to get.

 

[Karadjgne]

I'd not advocate aluminium for anything other than an aio. Even the EK stuff is rather limited in application. Can't put anything nickle or copper with it, so changing out a block or stepping upto a gpu block is nigh impossible. Cheap yes, but you've just created a user fixable aio in all reality.

For a fan, you'll not do much better than the Noctua A8. It's extremely quiet, @ 18db(A) at max speeds, capable of almost 50cfm. That's equitable to many 120mm fans. It also is a higher static pressure fan. Just don't let the numbers tell the whole story, static pressure isn't standardized as such.

Better off in pull with those rads, rather than push, unless planning on running fans @ 2000rpm. Push, you get dead space under the motor housing, no airflow through the fin area, the 'dust donut' affect. With 80mm fans, that's important as the actual blade area of the fan as compared to the motor size, is rather small. That forces the need for more air in an even smaller area.

Pull creates a vacuum in front of the blades. That vacuum is filled by air pushing through the entirety of the rad face. No loss of area from the motor housing. So while you don't get the same 'breeze' from the fan face as you do from the fan exhaust, the overall affect is higher efficiency of the rad. On an 80mm rad, it's closer to double.

I'm using 2x Noctua A12x15 (15mm slim fans) on a 22fpi rad at @ 450-500rpm and 2x Noctua A12x25 on a 20fpi rad @ 450-500rpm. Both in pull. Raising the rpm of both sets to 1000rpm drops coolant temp 2°C, so there's no real need for more.

For many years, the 2 best rad fans available were the Noctua NF-F12 and the Scythe Gentle Typhoon. Strange thing about both those fans was the stats, both were very mediocre for cfm and static pressure, there were plenty of designs with higher. But it was the balance or ratio of sp to cfm that made them so effective. Only the Deltas got better, at the cost of noise. If you've ever been in a Server room, bring earplugs. 60+ decibels is far from quiet.

The issue with many of the better Delta designs is power draw, most motherboards cannot supply the 3A (ish) some fans require, so by necessity, they'll be uncontrolled, direct psu hookups.

 

[Austin86]

So I got the arctic P8s and I have to say they do rather well. I got the 3k RPM ones and they push a little more air thought the rads wile being much more quite then the old AC ryan fans.
I did try a nf-a8 fan that I was able to borrow from a friend, wile a nice fan it was only able to push air though the rad at max speed and that was hardly any air.
Thanks for the advice and help everyone!