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Chip LevinsonFlag for United States of America

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XRackPro2 4U Noise Reduction Server Rack

Hi,

Does anyone have personal experience with the XRackPro2 4U Server Rack?  It is a enclosed rack designed to reduce noise.  I am thinking of buying one just for my noisy PowerEdge 2950 and putting it on top of my PowerEdge 24U rack.  All the other hardware (UPS, switches, modems, backup devices, etc.) would stay in the Dell Rack.

http://www.xrackpro.com/v/vspfiles/V4_Backup/xrackpro4U.htm

A retailer said that it reduces noise 80%.  If I understand decibels correctly, this would be a reduction of a little more than 6 decibels.  The 2950 is very noisy and I have tried many things to cool it to keep the fan speed down.  The server sits 5 feet from my desk in a closet - but the noise makes it through the closet doors.

One concern I have is heat.  They claim the one fan on the box can dissipate heat.  The problem is that if heat builds up just a little bit, the fans go from 5400 rpm to 7,000 rpm with a big jump in noise.  I can see a scenario where I will hear no difference because the 80% sound reduction would be offset by the server making more noise since it is running hotter.

I am open to other brands of noise reduction racks, if we keep this at $1,000 or less.

Thanks!
Chip
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hi dlethe,

Good to hear from you again.  20+ year ago I could have been that grad student making the calculations (have a bachelors degree in Chemical Engineering and have "fond" memories of thermodynamics).  Sadly, I would have no idea now where to begin with the calculations.

I have some of the numbers you are looking for:

1. Ambient temperature - 75F - 80F
2. Air displacement is 76 cfm.  They use a proprietary 119mm x 38mm fan (I suspect it is 120mm) and it uses a 2 pin plug.  Until I see it I won't know if I can replace it with a different fan if needed.  I have a bunch of 120mmx25mm b-Blasters that push 103CFM at 35 decibels.  I also have a bunch of 120mm Silenx that are silent at 18 decibels and claim to push 90 cfm but I think its closer to 75.

The unit's interior volume is 7.4 cubic feet empty.  With the 2950 installed this drops to rough 6 cubic feet.  So the one fan can in theory do 5 air changes every minute.
3. The 2950 will generate between 1,200 and 1,500 BTU/hr, depending on load factor.  They sau their unit can dissipate 700 BTU per rack height so the 4U unit can handle 2800 BTU.
4. It uses positive pressure - hot air is pushed out the back of the rack while the air intake is a filtered opening at the bottom of the rack in front.

I spoke to the manufacturer yesterday and am trying to arrange a live demo at their LA office.  If they agree, they will set up the unit with a noisy server and let me hear the before and after.  I will keep this thread open in case others have first hand experience.  I will also post the results of my visit.
UPDATE:  I ordered one today.  It should arrive on Friday.  I plan to pull the 2950 out of the rack and shoot a video of it running normally, at full fan speed and then repeat with it in the case.  I will post my review on YouTube and include a link in an update so others will know how well it works.  I will hopefully have that video up by early next week.
UPDATE 2: Unit arrived today - I will try to run the sound test in the next few days.
I finally had a chance to test the XRackPro2 and I can sum it up in one word - FANTASTIC!!

The unit did an amazing job of reducing noise.  I wish I knew about this before I spent countless hours and hundreds of dollars looking into rack fans and other cooling alternatives.

I shot some video of my testing that I will try and clean up and post as a review.  For now, let me share some sound numbers courtesy of a Radio Shack Digital Sound Level Meter.  

I pulled the PowerEdge 2950 out of the rack and set it up on a table.  When I started the server the sound level jumped to 95 decibels for 10 seconds or so and eventually settled down to 71 decibels.  After giving the server an hour to warm up the noise jumped from 71 decibels to 78 decibels (roughly 4x louder).  As a point of reference, according to one site a power lawn mower is 96 dB while a motorcycle at 25 ft is 90 dB, and a garbage disposal is 80 dB.

When I installed the 2950 in the XRackPro and gave it a minute to get over the start-up, here is what happens to the 71 dB noise:
- 52 db at the front glass door
- 62 dB at the back near the exhaust fan

So the noise was decreased between 9 and 19 decibels!

I then removed the top of the server, causing the fans to spin at near maximum speed.  The server was generating 90 dB of noise.  Once placed in the XRackPro, the 90DB dropped to:
- 65 db at the front glass door
- 75 dB at the back near the exhaust fan

In this much, much louder case noise was reduced between 15 and 25 decibels.

This product really works!!