I replace my three Norco ss500 fans with the coolink quiet fans. My disk temperatures are now in the high 30's and sometimes reach 40 which I get an alert email sent to me for when it goes over 40. My server sits in the basement which stays cool year round. I have the fans in the Norco's pulling the air out away from the drives, maybe they are supposed to be blowing on the drives? I only have one fan in my case and it is in the back pulling out hot air. Wondering if I should install more fans and which way to face them. Thanks for any help

It sounds like your new fan is not moving enough air. The cfm is to low.

 

A problem with many silent fans is that they spin at a lower rpm to reduce noise. This results in less airflow or cfm.

 

To answer your question. The front drivebay fans should be sucking in fresh cool air across the drives into the server. You should then have fans exhausting (blowing out) the hot air from the server. Due to airflow patterns and natural convection, it is best if the exauated fans are on the back or the top of the server.

 

This next part is where some people might debate this. When you have high density drive bays (5in3's for example) you should have good exhausting equal to or better then your intake. This creates a negitive pressure inside the server. The reson I suggest this is it relieves stress on the intake fans and they become more efficient for cooling the drives. When you build a server with positive pressure the drivebay fans tend to spin slower (reducing drive cooling efectivness) as they work harder trying to build up the pressure. They are already stressed trying to move air through a confind space. I can not stress enough. Don't cheap out and buy a $3 fan to protect several hundred dollars worth of drives. Get something that can do the job effectively (not picking on the op, saying in general).

 

 

Ps the google datacenter guys think a 30-40c is best and 35c drive is the optimum temperature for a drive. That they run some production  drives at 45c and do not see any significant increase in failure  rates after 5 years.

 

+1 to the above.

 

I'll add this as well. Do you have all of the drive bays full? If not, you may consider taping over the empty bay. Otherwise, the air will take the path of least resistance through the empty slot.

My server (Azza 910) has 3 ss-550s and also sits in a cool basement. After I replaced the fans in the ss-500s with the coolink fans I also noticed an increase in drive temps very similar to what you report. You have them moving air in the correct direction. I think the issue is that the coolink fans move less air. When I compare the stock norco fans to the coolink fans there is a significant difference in air flow. The coolink fans are about 22 CFM I believe and the norcos are easily more than double that.

 

After the coolink fan mod I improved my drive temps (now in the low-mid 30s with ambient ~25c) by replacing the exhaust fans on the case with higher CFM fans. I use a fan controller to reduce the rpm of these fans to an acceptable noise level while maintaining enough air flow/negative pressure to move a little more air over the hard drives and let the coolink fans work more efficiently. I also closed off all other openings on the case so that the only intake is through the drive cages and only exhaust is through the case fans (and probably psu).

 

The only thing that I don't like is the use of the fan controller. I not sure if this introduces an additional possible point of failure for cooling. Maybe I'm just over worried but I don't want the fan controller to fail and  loose the two exhaust fans. I appreciate any comments on the use of a fan controller in a server as it relates to reliability etc..

 

Hope this helps.

Awesome thanks for replies. There is one of my norco's with 4 empty bays. I also only have one exhaust plus the psu. So from what I read maybe I should add another exhaust and only use the norco fans as the only intake. I don't want to use a fan controller though.

The only reason I use a fan controller was to reduce the noise from the higher-than-needed-output exhaust fans. So no real need for one. In fact, I'm probably going to replace the exhaust fans with some that have the noise/CFM specs that I want without the use of a fan controller and get rid of the controller.

I have used the Antec TriCool fans with success.  They are by no means the most quite but the move a decent amount of air and the built in 3-speed switch makes it easy to change without having to by a fan controller of some sort.