Cooling Closet Rack Gear

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MySongRanHills

Limp Gawd
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May 27, 2011
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What kind of cooling do you guys use for closet racks? My closet is 6x3x8 with double doors and no vents in or out. Right now I have a 4U box w/ dual Xeons and 12 HDDs in there with a 1U switch and cable modem and the temps are pretty high when doors are closed so I've been leaving them open for now.

Soon I will be adding a new wall outlet (and breaker) to the closet so I'm thinking I'll wire in a switch and bathroom vent fan as well. Saw some 200-300cfm ones that would move a lot of air. Will this be enough? I live in Texas and keep the AC on 74-78 in the summer. My worry is there is little air flowing in. With the doors closed there is maybe a 1/4" gap between the bottom of the doors and the carpet.

If I can get temps under control I'd like to add another 2U server, a 2U UPS and about another 4U of switches/routers.

Interested to see what others have done.
 
I'd prefer not to cut holes in the door. Part of the reason everything is going in the closet is the insane fan noise. If I absolutely have to have air going in I'd rather route some AC into it.
 
Then that would be your best bet. Install a AC register and a air return in the closet.
 
You could always try cutting the door down slightly to get more airflow. A 1/2" gap isn't going to be noticeable, especially on carpet.

Then again with the cost to run an exhaust fan 24/7, you might be ahead just to plumb in A/C if that's easily doable.
 
Only concern I have is I'd hate to have the A/C coming in from the ceiling and then exhausting right into the attic cuz the exhaust vent is 4' away on the same ceiling. As a last resort I could run A/C ducting through the ceiling and just let the ducting hang to the floor to have the cold air coming out at floor level VS ceiling level.

How does everyone else deal with heat issues with a closet full of rack gear? Surely other people have same issues I'd think.

My initial thought was to use just an exhaust fan and then take other steps as necessary, but is it possible that just adding A/C alone to the closet could be enough?
 
People with a CLOSET FULL of rack gear most likely properly ventilate it... that means holes in and out ;)

Me, I'm planning to use digital thermometers I can set from outside the room that control fans and AC inside. My plan is to use outside air rotation depending on temp. differential, and then have AC kick on at a higher temp, and a smaller ventilation fan possibly on another sensor to vent the cold air back into house or hot air out.

Mine's a bit complex because I don't want to rely on 1 or 2 methods and would prefer to keep it as efficient as possible all the time, ie: AC off 90% of time.

Which brings me to my next thought... you could always move it to the basement or someplace that's naturally cooler and have an easier time maintaining temps.
 
ToddW2 said:
People with a CLOSET FULL of rack gear most likely properly ventilate it... that means holes in and out ;)

Me, I'm planning to use digital thermometers I can set from outside the room that control fans and AC inside. My plan is to use outside air rotation depending on temp. differential, and then have AC kick on at a higher temp, and a smaller ventilation fan possibly on another sensor to vent the cold air back into house or hot air out.

Mine's a bit complex because I don't want to rely on 1 or 2 methods and would prefer to keep it as efficient as possible all the time, ie: AC off 90% of time.

Which brings me to my next thought... you could always move it to the basement or someplace that's naturally cooler and have an easier time maintaining temps.
Click to expand...

In Houston there is no such thing as basements. Water level is too high.

Are you saying your going to use separate AC and thermostat just for your rack gear?
 
We've stuck our office wench, Samantha, in the closet with the gear. She's cold as ice so it's made a big difference. Another benefit is that we don't hear her BS anymore either. Give it a try and let me know how it works out for you.
 
MySongRanHills said:
In Houston there is no such thing as basements. Water level is too high.

Are you saying your going to use separate AC and thermostat just for your rack gear?
Click to expand...

That's exactly what I'm doing.

They make specific rack kits that mount the AC outlet to the front/rear of the rack. (That is if you can't make your own adapter)
 
air vent down low in a wall, couple quiet fans near the ceiling blowing out.
If you use thermostat controlled fans they are even quieter.
Since you should not use AC fans with a computer ups I use dc fans and a 12v power brick.
A ups rated for inductive loads can be hooked up to AC fans directly but since I have a ups anyway I use dc fans.
 
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A really cheap and easy thing to do would be to just have the air recirculate, and when it reaches 25C a damper and fan turns on to suck the hot air outside, and bring cool air in the front. It would do this till it drops 20C then continue to recirculate.

Of course you could go a bit more complex so that the heat is not wasted.

Just remember that if you remove air, it has to be replaced so your setup needs an exhaust and intake. Idealy exhaust from hot side and supply to cool side.
 
cut a hole at the top (so it enters the living space) and install a return-air register in it & be sure you have a half-inch space at the bottom of the door. pick one of the wide registers and be sure to install it at the highest point in the closet so the top of the register cutout is at ceiling height of the closet.

That alone will allow convection currents and cool the closet a lot. If that isn't enough then you can install some thermostatically controlled 115v ac fans blowing out the vent.

You'll be amazed how well it'll suck cool air through the crack under the door, even without the fans. If you can't get a crack under the door (or the double doors aren't louvered) you could install another small vent on each door.
 
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ToddW2 said:
That's exactly what I'm doing.

They make specific rack kits that mount the AC outlet to the front/rear of the rack. (That is if you can't make your own adapter)
Click to expand...

Can you elaborate or link to a product? I'm not sure if you have a shroud of some type that accepts AC duct on one end and then pumps air from your homes central AC or if you are speaking of an A/C unit that mounts to the rack itself.

Red Squirrel said:
A really cheap and easy thing to do would be to just have the air recirculate, and when it reaches 25C a damper and fan turns on to suck the hot air outside, and bring cool air in the front. It would do this till it drops 20C then continue to recirculate.

Of course you could go a bit more complex so that the heat is not wasted.

Just remember that if you remove air, it has to be replaced so your setup needs an exhaust and intake. Idealy exhaust from hot side and supply to cool side.
Click to expand...

waste heat lmao, if only. In Houston the heater gets turned on 10-20 days per year. In summer I keep the A/C around 74-76F( around 24C).

I haven't seen any fans that are thermostat controlled but to be fair I've been looking at bathroom fans. What kind are temp regulated?

bds1904 said:
cut a hole at the top (so it enters the living space) and install a return-air register in it & be sure you have a half-inch space at the bottom of the door. pick one of the wide registers and be sure to install it at the highest point in the closet so the top of the register cutout is at ceiling height of the closet.
Click to expand...
The only issue I have with this is that then I will be getting a lot of fan noise from the vent. Rather than do that I'd use a vent or fan in ceiling and just vent the hot air into the attic.
 
MySongRanHills said:
Can you elaborate or link to a product? I'm not sure if you have a shroud of some type that accepts AC duct on one end and then pumps air from your homes central AC or if you are speaking of an A/C unit that mounts to the rack itself.



waste heat lmao, if only. In Houston the heater gets turned on 10-20 days per year. In summer I keep the A/C around 74-76F( around 24C).

I haven't seen any fans that are thermostat controlled but to be fair I've been looking at bathroom fans. What kind are temp regulated?


The only issue I have with this is that then I will be getting a lot of fan noise from the vent. Rather than do that I'd use a vent or fan in ceiling and just vent the hot air into the attic.
Click to expand...

If you're looking for an all-in-one deal that you can pickup locally, you can probably find an attic fan with a built in temp sensor and electronic damper.
 
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