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[Aaron McQueen]

I need to replace the amp rack at my church.  The current one is mounted to the wall, with a glass front.  It provides little ventilation.  What do you use? I don't really need doors as the amps are in a secured room, so nothing fancy, just a rack.

[Mark Mattocks]

Mr. McQueen,

We typically use Middle Atlantic DWR or EWR series racks.  The racks that pivot away from the wall at the back are far better than some of the cheaper ones that are fixed at the wall.  The pivoting racks allow you to access the connections without un-racking gear (Please, route your wires accordingly.  All wires are fastened from entry to the hinged side of the back door to the inner section of rack to the connection point.  Wire tie and label.  Neatness counts.).

Also the Raxxess SWR series - NOT the WMK racks - the Atlas Sound 300 series - NOT WMA or 600 series - and Lowell Mfg L250 and L253 series - NOT the L55 series.  Many of these can be ordered without front doors or with vented front doors.  If there will be a solid front door that will remain closed, most of these racks have provisions to add fans in the top of the rack for cooling.

My opinion only -
Mark

[Adam Kane]

+1 on the Middle Atlantic stuff.  Whenever air flow is a concern, we usually order them with the perforated front doors.  That way we can keep them locked, but still breathing.

If you plan on going to a floor-standing rack, I suggest getting something with a caster kit because it's usually a huge pain to spin the thing around to access the rear if you have to drag it across the floor when it's full of amps.

[Michael Hoddy]

+2 on the Middle Atlantic lines already mentioned, I have used both for wall mounts for years. For floor-standing racks, I use the Middle Atlantic ERK series. Most of their racks come with a back door (if applicable), but no front door, so make sure you order one separately. You can choose from solid metal front, perforated, or plexi. The fan kit option is nice if you have a solid front door and need to keep internal temperatures down.

[Don Boone]

Why not simply remove the front door?

Don

[Aaron McQueen]

Mark Mattocks wrote on Wed, 03 June 2009 23:21

Mr. McQueen, We typically use Middle Atlantic DWR or EWR series racks.  The racks that pivot away from the wall at the back are far better than some of the cheaper ones that are fixed at the wall.  The pivoting racks allow you to access the connections without un-racking gear (Please, route your wires accordingly.  All wires are fastened from entry to the hinged side of the back door to the inner section of rack to the connection point.  Wire tie and label.  Neatness counts.). Also the Raxxess SWR series - NOT the WMK racks - the Atlas Sound 300 series - NOT WMA or 600 series - and Lowell Mfg L250 and L253 series - NOT the L55 series.  Many of these can be ordered without front doors or with vented front doors.  If there will be a solid front door that will remain closed, most of these racks have provisions to add fans in the top of the rack for cooling. My opinion only - Mark

Hi Mark,

Please don't call me Mr. McQueen, that makes me feel old.  Anyway, I think we have a Mid-Atlantic EWR rack now.  At least it looks very similar.  It swivels off the wall and and has a solid glass door.  It's a 16 space rack that houses 2 CE2000's, 2 CE1000's, 1 XLS402, and a JBL processor.  The rack is tight packed, no space between the amps.  We recently had one of the CE1000's fail, see my other thread here:

http://srforums.prosoundweb.com/index.php/mv/msg/42203/40315 5/12639/

I'm concerned that heat may have contributed to the failure of this amp.  Is there any airflow with this type of setup?  Or should I look at replacing it with the floor stading rack?  Or should I just replace the front door?

[Aaron McQueen]

Don Boone wrote on Thu, 04 June 2009 13:11

Why not simply remove the front door? Don

I could do that.  Do you think it would help? Or is that a dumb question?

[Hal Bissinger/COMSYSTEC]

I'm concerned that heat may have contributed to the failure of this amp

I'll bet money on it given the loaded rack and the door. I would get myself a digital thermometer with a remote probe and place it in the rack at various places in free air. This with the door closed under normal operating conditions. 85 deg F is max for me. Even a little higher and at the least you shorten the equipment's life.

I have one installation with a 21U floor standing rack and just one Crown CT-810 amp and some processing. It is sitting in a 3'x3' closet. With the closet door closed (as it has to be) the temperature in the closet easily reached 100 degrees in less than hour. Inside the rack it got even hotter in some hotspots. Some front panels were hot to the touch.

I replaced the solid closet door with a louver door, blocked the top part of the louver off and installed a furnace filter on the bottom half. I then installed a 200CFM blower in the top of the closet venting to the outside hallway. So now air is drawn in at the bottom, up through the rack and out the top. Temperature stays at whatever the ambient is outside the closet and everything stays nice and clean because of the filter- as long as you clean or change it regularly.

-Hal

[Mark Mattocks]

Aaron,

If the rack is in a secure area - lose the front door.  Unfortunately, the EWR racks do not have a top knockout for a fan panel.  I suggest reading http://repnet.middleatlantic.com/COMPANY/MarketingFiles/Temp InsideRacks/Thermal%20Management%203-04.pdf - Middle Atlantic's white paper on managing heat in racks - highly informative and lots of pictures!

-Mark

[Craig Hauber]

You need a bigger rack if it's tight-packed like that.  Upgrade to a 21-space DWR series -I find they have a bit more room and better ventilation.  We usually put spaces between the amps and use vented blank panels.  We also have been installing QSC amps because they suck from the back and blow out the front -Crowns tend to be the other direction -resulting in a pocket of really hot air behind all the gear and alot of dust.  With the DWR, just removing all the knock-outs top and bottom provides enough ventilation for incoming air -not to mention all your low-power processing gear isn't living in that pocket of warm air.

Definitely pull the door off.  If handling of amp-gains is an issue set your system up with security covers over all the processing and/or lock out the DSP and set it so all the amp gain controls are at max -so one quick glance can tell you if something has been tampered with.  If it has, the only thing someone can do is turn something down anyways which may not be ideal but at least no damage usually will occur to any loudspeakers.  (Another reason to use contractor type amps -no exposed front controls!)

You amps may not have failed entirely due to heat, check for clogging with dust too!  -I find that is more of problem that just doesn't seem to be addressed by the manufacturers in amps designed to be run 24/7.

[Mark Mattocks]

Craig -

If you are using equipment that has forced air front or rear intakes you should NOT use vented blanks between them.  Most amplifier manufacturers recommend stacking amplifiers tightly to keep air flow moving in the desired direction without creating 'eddies' in the spaces between - that is true for QSC as well.  With the QSC amps - having a vent panel between them will allow the hot air blowing out the front to be recirculated through the vent to the back of the amps above.  

http://repnet.middleatlantic.com/COMPANY/MarketingFiles/Temp InsideRacks/Thermal%20Management%203-04.pdf

Good reading about cooling racks.

Mark

[Rain Jaudon]

Snatch the front door off and see if its any cooler in there.

Thats free!

[Brian Bolly]

Back in my systems contracting days, we were using Middle Atlantic MRK-4431 racks with up to 14 amps in them, no blanks in between.  For large systems, amps were grouped together in 24's (14 in a rack, 10 in a rack, and so on).  Again, no space between amps is necessary, IF:

• You have proper HVAC within the roomAND
• You have proper pressure in the rack.

That said, there was usually a good 12+" behind the amps (31" deep rack), and even if it was "full" with 14 amps, there was 10-16 spaces at the top for air to move.  Also, rarely were there front doors on the rack, but almost always there was a solid back door.  If there was a front door, it was a vented/mesh door.

With so few amps, I doubt you have a thermal issue in the room (unless there's some other BTU-belching device), so simply removing the front door of the rack should get you some relief.  However, if you've got an EWR wall rack (16U?), there's probably very little way for air to flow through the rack.  If removing your front door doesn't buy you a few degrees, it might be time for a larger, better vented rack.

[Craig Hauber]

Mark Mattocks wrote on Thu, 04 June 2009 19:36

Craig - If you are using equipment that has forced air front or rear intakes you should NOT use vented blanks between them.  Most amplifier manufacturers recommend stacking amplifiers tightly to keep air flow moving in the desired direction without creating 'eddies' in the spaces between - that is true for QSC as well.  With the QSC amps - having a vent panel between them will allow the hot air blowing out the front to be recirculated through the vent to the back of the amps above.    http://repnet.middleatlantic.com/COMPANY/MarketingFiles/Temp InsideRacks/Thermal%20Management%203-04.pdf Good reading about cooling racks. Mark

I understand with large banks of amplifiers that run hard you have to adhere to the "rules" alot more but I have always found that everything seems to run cooler with spaces and vent panels in the cramped confines of a DWR rack.  Actual chassis and sheet-metal temps -and I've wondered about the circular suction thing but never actually noticed it happening when feeling around in the space between the amps.
Keeping the fans running at a minimum or not-at-all (if the amp has that feature at idle) really keeps the dust clogging down.  I've found that tight-packing the amps they would run on high fan-speed constantly.  (dust seems to be the worse problem in my club installations)
I also consider other rack occupants as well, such as the DSP and other non-amp gear (wall-warts, RDL modules etc) too.