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A Micro-A/C for a Server Closet?
DiZNoG asks: "I work from home and run two businesses from there. Sick of server and switch noise in my home office, I've been thinking of taking an old hallway closet that used to house the furnace (since moved) and turning it into a literal server closet for my various servers and networking gear. I have 4 servers and various networking gear and even a system for getting everything in and accessible worked out. Bonus, the room already has power and is perfect placement for my access point (already secured, thank you!) However, I am running into problems finding a small air conditioner for the size of room. It's literally 15 sq. ft. and maybe 100-125 cubic feet total. By my estimates that's something on the order of 150-250 BTUs (or less) with the hardware. Does anyone on Slashdot know of micro A/C units to keep such a small area in server friendly temperature efficiently? I did see this homebrew action, but I'm looking for much less maintenance."
The square footage of the space has almost nothing to do with the size of the cooling unit you need. You need to base it on the wattage of the equipment you're going to put in there instead. Divide the wattage of your equipment by three to get an approximation of the BTUs per hour rating you'll need on your AC unit. Regardless, the laws of thermodynamics require that you will have to cut a vent hole for the heat to exit through even if you're using an air conditioner. As long as you're going to have a vent hole anyway, why not cut two? Put a big slow quiet fan in the top one blowing in, and an air filter in the bottom (or the other way around)?
If you insist on AC, you probably want something like this: APC NetworkAIR AP7003 or more likely, some other (cheaper, but similar) portable AC unit with an exhaust hose from your local Wal-Mart.
I'd recommend one of these. The twin fan design can be set to exchange, and the controls can be set to certain temperatures so that you're not wasting energy in the winter.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
If it was used for heating at one time perhaps you could use a fan to fee the air into the ducts in the winter months (assuming your winter months are like my winter months
Trolling is a art,
for a situation just a bit bigger than what you described: http://www.getcozy.com/fff.html. We like it. Here in Seattle we get quite a bit of condensation that needs to be emptied (or pumped if you want). This place also has other options you may wish to look at. Nice guys too.
Tear out your normal furnace altogether. Then install some ducting and fans, and use the room to heat your whole house.
I've always want to try a winter vs. summer solution.
In the winter, just vent the heat towards the room you spend the most time in.
In the summer, take in air in near ground level (if not prone to floods!) and venting it up and out by convection or just out the nearest wall if fan forced. A steady flow of air, even if it's humid and 90F will keep your servers pretty happy so long as the amount of air is sufficient. A muffin fan won't be enough, but a 6'' duct fan should do the trick.
A more "green" solution would be to switch to fewer, smaller, lower powered servers so that you generate less heat in the first place. A modest laptop running linux/bsd/solaris can actually be quite a powerful server and can handle several services at once.
then get an a/c unit sized that big.
Consider labyrinth ducts and a forced air fan. Put the fan in the server closet, build labyrinth ducts in and out of the closet. Labyrinth ducts have been used for years to sound isolate recording studios from each other.
"Eve of Destruction", it's not just for old hippies anymore...
I'm assuming that the through-the-window models won't help you, but one of the portable ones might. To pick one at random, consider this portable A/C unit. The advantage of something like this, as opposed to the window fans that some others have suggested, is that it should come with an exhaust hose that you can channel to either the furnace's exhaust pipes, or to some other appropriate outlet elsewhere in your home. Something like that ought do do exactly what you need here.
DO NOT LEAVE IT IS NOT REAL
If the closet is adjacent to a bathroom, you can do what a friend of mine did--cut a hole in the wall and pipe the exhaust heat from the closet server into the hollow area behind/beneath the shower/bathtub. Not only does his server stay nice and cool, but his wife never complains about a cold bathtub again!
Oh, wait! If you keep the intake side as it is above, but you have only one exhaust tube through the door, with the computer exhausts exiting into the room, you can attach to it a realtively ( compared to the computer fans ) powerful fan blowing out of the room. This will draw extra air through the computers, keeping them cooler and the extra volume of air will keep the room cool.
...
How about this A/C unit?
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http://www.hvacportablesystems.com/images/210airc
Check the RV market - there may be something small that won't leave you with a buttload of water to take care of as well. Of course, most of the RVers I know go the cheap route and use a small window shaker unit - under $100 at walmart, home depot, etc. Heck, I've got one to run with my generator for when the power goes out for a week like happened to me with the 'canes last year.
Of course, you could vent it instead. Use just enough fan power (blowing into attic or out or whatever) to create a very small negative pressure - you don't want to AC the world. If you should need heat elsewhere, block off the vent, reverse the fan, and leave the door open. My dual AMD rig provides a nice 5 F. boost in the room it lives in.
Don't blame me, I voted for Kodos
Conversion factor: 1 KWH = 3412 BTU
Multiplying the average (not peak) wattage by 3.4 will get the BTU's per hour of cooling capacity.
Use an RV air conditioner. They are frequently used for cooling small cubicles. You may have seen them on the booth that the gas attendant sits in at gas stations. Of course, you'll have to comply to local building codes
"I'm not impatient. I just hate waiting." - My Dad
Just put a fan on the ductwork that should still be there from the old furnace blowing the heat out through your house. Then you get the bonus that it helps heat your house in the winter, and it'll use your existing a/c to cool it all off in the summer (if it pulls in the air from under the door, and blows it out from the cieling). That way you don't have to wire in anything more complicated than a fan, and everything'll still stay nice and cool.
Search for it; it's what you need. Not cheap, but doing something the right way rarely is.
"As God is my witness, I thought turkeys could fly." A. Carlson
My results have been so-so.
First I tried one of the portable units. Two caveats with them:
1. Get one that has TWO ducts, these suck in air through one to cool the condenser ("outside") coil, then blow the hot air out the other. I got one that had just one, which means it uses some of the room air to cool the condenser. Problem is, in my closet, that meant enough air was being sucked into the closet from the rest of the house that the unit effectively never shut off. Not desirable.
2. Be careful where you vent the exhaust. Many models now have a pump that dumps the condensate over the condenser coil to help increase the cooling. This means the exhaust air can be VERY humid, and you probably don't want to just dump that into your attic. (Oops... I did that...) Especially if it's cool outside (thus the attic is cool) you may wind up with a lot of water collecting in the insulation. So vent it outside!
I decided I wasn't happy with the way the portable worked, so I actually installed a mini-split. WAAAY too big for the room (it's 9000 btu and the room's about 6ft square) but with the application of some extra controls (I work for an HVAC controls company) I managed to keep the runtime reasonable.
You may be able to find smaller units - some people have suggested RV units, that might work better. Just be sure to get "low ambient" options if you live where it gets below 60 degrees outside, and you expect to need it during the winter. Otherwise, you'll be replacing the compressor after the first winter. Basic low ambient items are some heat tape wrapped around the compressor and a pressure switch that cycles the outdoor fan.
If your heat levels aren't too bad you might get away with just a bathroom exhaust vent in the ceiling. I bought a combo light/exhaust fan and replaced the closet's light. Installed a line-voltage thermostat on the wall, and now the exhaust fan comes on if the closet gets too hot. Make sure the closet door has a decent gap at the bottom to allow air in. Unfortunately, my heat load was high enough that the fan pretty much ran all the time...
There needs to be a hole for the A/C to go in, but the heat goes out through the A/C.
It scares the hell out of me. I have nightmares of the A/C wearing out, allowing our 8 servers to heat up the small server room, starting a fire and taking out the building, which doesn't have ceiling sprinklers because of the other damage it'd cause if there was a false alarm. It's better than what the server room had before, nothing at all. Whoever designed the building manage to make the server room be the only room without air conditioning. It was only after months of complaining that they installed any sort of cooling in that room. They're lucky nothing died in the 90+ degree F heat.
If it's a small server room, with a small number of servers, maybe try TWO small household A/C's, not sharing the same power socket.
And maybe a remote. OK, cheapest known brand. My eighty dollar 10,000 BTU Panasonic AC would probably work well. The fact that it's overspecified should translate into reliability, and the thermostat means that you won't be running it all the time. Generally, larger units tend to be more efficient, so you should be saving money everywhere. If the noise troubles you, you might locate it remotely with ducting, which you'll need anyway (although since there was a furnace in there, you should have some ducting already in place. Again, if it's overspecified, you may be able to run it at a lower setting so that it's quieter than a smaller unit moving the same number of Calories around.
The remote wouldn't hurt if it wasn't in the most convenient place, either.
Window AC units can be very reliable. My grandparents had one that was older than me, and ran all summer, struggling to cool a space too large for it. At least it ran until it iced up on a humid day, & had to be turned off for awhile to defrost.
Assembly is the reverse of disassembly.
I live in Florida and have a hallway closet serving as a server closet. Currently it has one PC (333 MHz AMD minitower with 4 HDs), my DSL modem, a router, and an access point. In the past it also had a 500 MHz Compaq Deskpro EN SFF (85W PS, I think) and an ancient 120 MHz full-size Compaq Deskpro.
I keep the house at 75-80 degrees, the closet has louvered doors, and heat has almost never been a problem. I ran into an issue once when something was wrong on the AMD and it would go to 100% CPU long enough to set off the alarm on the ASUS motherboard, but other than that, all 1/2/3 machines (at various times) have been humming along for over 3 years.
As for you, you might want to tap into the house's main AC and run a little 2-4" pipe for a bit of cooling, but that's as far as I'd go. I've had to replace a fan or two along the way, and one HD died, but that was an old (at the time) 6.8 GB IDE drive that probably had no business being in a 24/7/365 machine in the first place, so heat probably wasn't even the cause of that anyway. I haven't seen any more failures in that closet than I have with any other machine anywhere else in the house.
Laws of thermodynamics dictate that you can't put a window unit in there or anything (assuming this closet is not against an exterior wall)--that would heat up the rest of the house. IF you need cooling, run a duct from your existing AC. If you don't have AC at all, then a couple 6"-8" fans should move enough air. Assuming you don't have an airtight closet (louvered doors highly recommended!) you could have one or two fans drawing air up through the closet and exhausting into the attic.
Basically, think of the whole closet as being one giant computer case and plumb accordingly. And of course it wouldn't hurt to hit Radio Shack for a $20 digital indoor/outdoor thermometer to keep an eye on things.
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why not just cram an old refrigerator in there, mod the interior to support rack gear? you could even put that overclocked celeron 300a you used to want so bad up in the freezer, running at a cool even G (1 Ghz).
Find your nearest garden supply store that carries hydroponic gear. Now find the scruffiest employee therein. He'd be a great source of info on setting up ventilation systems in small rooms.
Literalism isn't a form of humor, it's you being irritating.
If the furnace used to be in that closet then it probably had a louvered door for intake and there's probably output ductwork still run to that closet. Just tie that ductwork into the house's HVAC return and let it pull air through that closet with the bonus that the heat will get spread out evenly during winter and it'll probably be cheaper to let your heat pump work a little harder during summer than to operate an additional unit.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
> had to be turned off for awhile to defrost
:)
I have an AC like this in the office where I work. We're the desktop support group, so naturally we keep our door open so people will walk in and ask for help. This means we also air condition the hallway. For some reason, when run like this, the AC unit eventually fills up with water and starts spraying it all over our precious computers. Instead of choosing between water-free computers and a cool room, we got a fish tank pump, duct-taped some tubing on to it, and stuck the tubing into the AC unit. We turned it on and let it drain into a bucket. After a day or so, we got about 6 gallons of water out. We now run the pump whenever the AC is on and haven't had any problems with the AC spraying water or icing up. The true geek solution
My other car is first.
This is not a major problem in a typical computer room because opening and closing the door only lets a relatively small proportion of the cold air out. But with a closet, you are likely to lose a large proportion of the air ... especially if you
have to leave the door open to give yourself room to move in the closet full of
servers. Even building an "air lock" won't help much.
If humidity is an issue, you may be better off fitting an exhaust fan.
As long as you're going to have a vent hole anyway
Since the OP said that the closet used to house the furnace, there's probably already a chimney anyway. If it was an old furnace it actually lost some heat out the chimney, some of the fanciest new ones have cold exhaust, but either way, there's probably a duct ~5-6" in diameter that goes to the outside. It may have been plugged or blocked when the furnace was removed, but it's probably pretty easy to get to.
Since the servers probably don't produce all that much heat, either just let the heat exhaust itself passively by putting some louvers in the door to supply makeup air, or maybe add a fan to force air out the duct. Either way, it probably doesn't require an air conditioner, which would probably use several times as much power as the servers.
For some reason? Air Conditioners also do dehumidification, so you're just getting extra humidity from the hallway of course.
sounds pretty impossible.
Is that why they're in use in most of the new HP Proliants? http://www.linuxelectrons.com/article.php/20050427 19320516
Self contained, small, low maintaince, powerful (low end units are about 1800BTUs), includes a drain line, and air filter.
Down side is the price.
III.IIVIVIXIIVIVIIIVVIIIIXVIIIXIIIIIIIIVIIIIVVIII
Assuming a few things about your setup, this is the solution that I would use (and have in the past).
Get an extra ATX power supply. Doesn't need to be real powerful or anything. Then purchase a couple of computer case fans. I'd get the 5.25" kind, because they spin slower and will last longer while still putting out a decent CFM rating.
Cut a hole about 1' from the bottom of the closet door. Mount a fan so that it blows the air in here. This is your intake. Put a filter on it if it makes you happy.
Cut another hole about 1' above the higest piece of equipment in the closet. Mount a fan so that it exhausts the hot air from the closet.
Connect both of the fans to your power supply and then set the power supply on a nice wood shelf. Connect power supply to the UPS that your equipment is running on.
Given the small load that you discussed, I would think that this setup would have you totally covered. You _MAY_ need to go to two sets of intake fans, but you should never need more than one exhaust.
Don't just set an AC in the closet, as that will actually raise the temperature.
I knew someone would point this out :)
What I meant is that for some reason the AC unit doesn't drain like it's supposed to.
My other car is first.
Pick up an industrial electrical enclosure cooling unit. Check out Pfannenberg or Hoffman. You will have to go through an industrial supply distributer who will try to screw you on cost if you explain that you are not an industrial customer.
You are way off on your heat load calculations. You should look at the electrical service in the closet. For electronic equipment, very near 100% of the electrical power ends up as heat. If you have one outlet rated at 15 amps then figure your max heat load to be:
15AMP x 120V x 3.41 BTU/hr/W = 6,138 BTU or roughly 0.5 TR (tons of refrigeration)
If you are using much less that 15AMP (and you almost certainly are) then use a clamp-on amp meter to measure the actual current (add in a safety factor...say 30%). More realistically you should probably just ventilate the closet to an air conditioned area of your home.
Simple people talk of people, better people talk of events, great people talk of ideas.
Liebert has something like that, I saw one once. It was pretty confusing how it actually worked.
It fit in a 2' square suspended ceiling, in place of a ceiling tile. It had a little output, about a 4" hose, blowing cold air.
No unit outside the building, not a split system. Not much wiring, not much power. It was weird. Blowing cold air into a server closet I was in. It made little noise. All self contained. Low capacity. I wondered what they did with the heat. Nothing it seemed.
Weird.
Liebert is of course the company that makes those giant UPS and AC units for server rooms. The really big ones.
.
I have crappy AC in my office, so I had to get a rigged AC system.
Haier has one that is about 30" tall, foot deep, two feet wide, maybe $350. Best part is, it evaporates the condensate in the exhaust so you don't have a drip pan to empty (like some other portable AC units or a wall unit). You do have to vent any cooling unit, so that will always be a problem. You can't just cool a room using electricity, the work is going to generate heat somewhere and that has to be vented.
Stick them in a refridgerator.
Computers are useless. They can only give you answers.
-- Pablo Picasso
Unless you live in a modern construction home with a moisture barrier house wrap. Then any excessive interior wintertime moisture will just slowly migrate through your drywall, through your fiberglass bats, and condenses against the cool exterior sheathing where it will help foster rot and mold!
Modern constructions methods might be more energy efficient, but at a steep cost.
Generally, larger units tend to be more efficient, so you should be saving money everywhere
not true. you are confusing size with efficiency. you need a certain size in order to cool a certain amount of space effectively; too small and it never turns off, too large and it constantly turns on/off thereby shortening its life. you need a certain efficiency in order to save money.
it's just like buying a car and choosing the right engine for it. typically a smaller engine for better fuel efficiency, while a larger engine for more pulling power. and even then there are differences such as choosing diesel over gasoline if you are always pulling a load. reason? diesel engines generate MUCH more torque per energy unit than gas and the engines on the average last a lot longer than gas. but I digress.
you need to figure out how much heat/BTU's you will be generating, or could generate, tack on a reasonable safety factor above that, then select the appropriate unit. since I don't have the floorplans to your house, I can't advise on what to do. if you have a one-story, you could conceivable get away with no a/c unit at all and vent directly to the attic with enough airflow. this also depends on where you live and what your local climate is like. the above suggestion wouldn't work for me since I have a 2-story and live in Austin Texas where it got hot as hell this last summer and I had an old inefficient failing heat pump I couldn't afford to replace at the time so it ran constantly.
good luck.
I'm good with numbers -
The OP didn't say what the four servers are, but if they have 300 watt power supplies, then four of them is 1200 watts, which is getting up into the toaster and hair dryer area. 1200 watts is 4092 btus/hr, more if you have monitors, hubs, switches, or even a light bulb in there. And if the AC itself is in the closet, then you have to add in the heat it generates. most little A/C units are no better than a EER of 10, so a 4000 btu/h unit will add 400 btu/h for itself. Which means you need 5000 btu/h unit. There are lots in the 5000 to 6000 range. Water cooling can make the unit quieter, but will add $$
I have five machines (older workstation chassis repurposed as SOHO servers) a 24-port switch, DSL gear, a couple of laptops as NOC monitoring stations, and enough UPSes to run them all, in the former laundry closet of the house we remodeled into our office. We have a high-capacity centrifugal bathroom vent fan sucking air off the top of the room and ducting it down flexible metal vent hose, and out the old dryer vent outlet. The doorway to the room is weatherstripped around the edges and we cut a 30"x3" intake vent in the bottom panel of it. On the inside of this vent intake we use COTS furnace air filter media -- buy on a roll at Home Depot and cut to fit. Spray with a little aerosol oil (WD40 or actual air filter oil) to catch dust better. Change filters every few month or when they get grubby. The closet is located in the basement of an air-conditioned building, so the intake air through the bottom of the door is already the coldest in the building.
All the gear is on metal restaurant-style wire shelving (black of course, came from Target, $40 for a 4-shelf unit) for better airflow, and stylish looks. We installed a $15 indoor/outdoor thermometer, sitting on the bottom shelf with the exterior probe taped to the ceiling. It monitors and records temp extrema at those two locations, which usually differ by about 3F.
I have never seen happier and cleaner SOHO servers. We never visit the room anymore -- I went in to plug a new network drop into the switch the other day and had to fight my way through cobwebs it'd been undistrubed so long. As a plus, we had to do extensive drywall work during the remodel, and took the opportunity to pull 4 Cat6 network drops into every room (except the kitchen and baths). The conference room is rigged for 6 drops, for after-hours LAN parties. We have a network diagram posted on the wall of the server closet, making it easy to reconfigure the network to partition off part of it for games, so as not to disturb the rest. We'll soon be adding a real punch-down patch panel on a suspended 1/3rd rack and upgrading the switch to Gigabit and moving it to the rack, which will clean up the wiring quite a bit.
I'll see if I can find some photos of it to post.
-- There is no truth. There is only Perception. To Percieve is to Exist.