URGENT Can someone help me pick a fan for blowing cool air into a room

euser1984

At the moment I have this http://www.vortice-export.com/default.aspx?idPage=313&idProdotto=141009

This is intended for extracting cold air although I'm using it to pull air in from outside. It's not powerful enough though. Can somebody recommend something for me that will do the job. Maybe twice as powerful/ twice as much air.

Bruthal

What is it your trying to cool though, if its just a room with people in it, the air outside your taking in could well be warmer than the air inside on warm days, which would need air conditioning with cooling to cool the room.

If its a room with equipment that is heating the air in the room and just needs a high rate of air changes to keep equipment or plant from overheating, then a bigger fan might do alright.

euser1984

It's computer equipment, a few powerful machines with serious cooling required. I can't the power a conditioner uses- Nearly the same as all my machines combined 3.5kWh for a conditioner :O. Is that fan I linked to ok for blowing air in. It's actually designed for taking it out.

Bruthal

euser1984 wrote: »

It's computer equipment, a few powerful machines with serious cooling required. I can't the power a conditioner uses- Nearly the same as all my machines combined 3.5kWh for a conditioner :O. Is that fan I linked to ok for blowing air in. It's actually designed for taking it out.

Yea the fan should work either way, but when extracting with a powerful fan, there has to be adequate vents into the area to allow air to come in to replace the air at the rate the fan is capable of extracting it, and it would be the same for taking air into the space, there would need to be enough vents etc to allow the air out of the space to outside at the rate your fan can blow it in from outside, to get the maximum air change rate from the fan.

euser1984

robbie7730 wrote: »

Yea the fan should work either way, but when extracting with a powerful fan, there has to be adequate vents into the area to allow air to come in to replace the air at the rate the fan is capable of extracting it, and it would be the same for taking air into the space, there would need to be enough vents etc to allow the air out of the space to outside at the rate your fan can blow it in from outside, to get the maximum air change rate from the fan.

Thanks. What kind of vents would you normally use for taking the hot air and is it up high you place them? Would a fan of the same power blowing in work for extracting?

Thanks.

Bruthal

Id say myself that extracting the air would work better, as this will draw air into the space from everywhere it can through any vents etc, so you wont have this blast of air inside the room, but a more even airflow.

Is this setup in a room in the house or a shed?

euser1984

It's in a shed.

Bruthal

You can just put a couple of vents on the opposite side to where you put the fan extracting, and that should do it. Any sort of grille etc, or a couple of them to allow a good flow of air through.

antoinolachtnai

The rating on an air conditioner is the amount of energy it pumps, not the amount of energy it draws from the supply. You need to talk to an a/c company about this.

There are other advantages to a/c for machine rooms as well as the cooling. They give dry air, for instance. Also, the air is going to be reasonably clean, something that won't necessarily be the case with a fan. Having dry air should mean you avoid condensation. Still, air conditions are not the b-all and end-all of cooling comms rooms as they are sometimes made out to be.

The fan you have - is it in series (i.e, pointing in the same direction as) the fans on the computers in your rack? If it is fighting against them, this will reduce the effectiveness.

Personally, I would suggest extracting rather than blowing in air.

If you can 'segregate' hot air from cool air (i.e, the air on the hot side of the machines from the cool side of the machines) the cooling gurus reckon it will make a big difference to performance. The reason is simply that all the cold air you bring in is forced through the computers' fans and then immediately extracted, rather than mixing back with unheated air before being extracted.

You don't need to have a computer room super-cool. 22 degrees or even a bit hotter will be fine for computers. Cooler is better, but the latest research reports that a few degrees hotter doesn't make much difference.

If it is a shed, it really should lose heat pretty quickly in our climate especially if there is a bit of rain on it. I suspect there is a bit of solar gain going on. You could paint the roof silver and insulate it, it might make a difference.

Don't take my word for any of the above, there is an extensive literature on eco-friendly data centres. See for example http://www.youtube.com/watch?v=JZUX3n2yAzY

Bruthal

antoinolachtnai wrote: »

The rating on an air conditioner is the amount of energy it pumps, not the amount of energy it draws from the supply.

No one said much about air conditioner ratings though i dont think, thats a very simple concept anyway with heat pumps, as in its rating is its heat transfer capacity, all we are talking about here is air changes in a shed to prevent it getting too hot inside, not heat transfer evaporators and condensors etc. If air conditioning is needed, a simple split unit is all thats needed for this. But for 3 computers its unlikely to need that. Or a big chiller out behind the shed:D

Personally, I would suggest extracting rather than blowing in air.

Thats been mentioned as well. These machines will likely operate fine as they are. And air changes in shed will just keep it that bit cooler.

antoinolachtnai

For sure. The reason I mention the ratings is that the OP mentioned that the cost of running the AC would be more than running the equipment, and I am making the point that this is unlikely to be the case. Sometimes you just need AC, even with a relatively small number of machines. This should not be the case in a shed which should have plenty of free cooling.

You are right that these machines will probably be fine. Obviously we have limited information about the shed and how hot it actually is.

Bruthal

antoinolachtnai wrote: »

For sure. The reason I mention the ratings is that the OP mentioned that the cost of running the AC would be more than running the equipment, and I am making the point that this is unlikely to be the case. Sometimes you just need AC, even with a relatively small number of machines. This should not be the case in a shed which should have plenty of free cooling.

You are right that these machines will probably be fine. Obviously we have limited information about the shed and how hot it actually is.

Yes indeed your right, OP did mention about the AC running cost alright, im going blind:D, a split unit would use less than the 3 computers alright. Only about 1kw for one suitable for a living room size area probably.

paddy147

2 way comms cabinet fan system wil do this for you.

Thats what we use in Ebay and Intel.

Stoner

I think extracting the air from the source of the hottest air is a good idea aright.

If you extract the air from a low source to a high source the fan will assist the natural flow of heat, the heat will want to rise and leave at a high level.

so by using this fan as suggested by others in extraction mode and by creating a path that hot air can rise up and out of the shed the fan will be assisting the natural air flow of heat leaving the building at high level, but entering from low level, maybe from a vent in the shed on the shaded side.

That fan looks fine to me, have you much ducting on it? that will add resistance so you'd need to keep the extract point high and with a short length of flexi duct.

you'll end up with a fan assisted natural ventilation system, not the best solution for a server room though

euser1984

The idea now is to get someone in to setup an enclosed room and keep the ambient temp in the room at 25 celcius via 2 fans extracting and delivering. The fans will be temperature controlled.

The machines will then be able to cool themselves with case fans given this ambience.

antoinolachtnai

The problem is that if you use two fans like that, you may just create a draught between the two fans. It will cool the space in between, but the cool air won't really disperse. You'll end up with a cold spot, but the overall cooling may not be sufficient.

That is a massive amount of fans. So it might just work as you propose.

If you do this, be sure to put the extract on the hot side (behind the computers) and the intake on the cold side.

Why not set both fans to extract, and put them behind the rack (the hot side), in a high position?

For extra points, use plexiglass or similar to segregate the hot end from the cold end. This will force the cold air through the computers.

The temperature control needs to be based on the temperature in the hot area, not beside the fans.

Interested to hear how it works out and what the practical problems were, whatever way you do it.

Bruthal

euser1984 wrote: »

The idea now is to get someone in to setup an enclosed room and keep the ambient temp in the room at 25 celcius via 2 fans extracting and delivering. The fans will be temperature controlled.

The machines will then be able to cool themselves with case fans given this ambience.

I wouldnt put fans feeding as well as extracting i dont think, you will just have an air current straight through, and the air wont change as efficiently as just extracting, because with just extracting you are creating a lower pressure in the space which assists in changing most of the air volume every so often.

I would say the ideal setup would be air intake vents in front of the comuters with the computers own intake vents facing the space intake vents, and extract at the opposite end of the space.

A stat set to bring on the extract fan at 25 degrees might work, and adjust it to get the best cycling setup probably.

euser1984

antoinolachtnai wrote: »

The problem is that if you use two fans like that, you may just create a draught between the two fans. It will cool the space in between, but the cool air won't really disperse. You'll end up with a cold spot, but the overall cooling may not be sufficient.

That is a massive amount of fans. So it might just work as you propose.

If you do this, be sure to put the extract on the hot side (behind the computers) and the intake on the cold side.

Why not set both fans to extract, and put them behind the rack (the hot side), in a high position?

For extra points, use plexiglass or similar to segregate the hot end from the cold end. This will force the cold air through the computers.

The temperature control needs to be based on the temperature in the hot area, not beside the fans.

Interested to hear how it works out and what the practical problems were, whatever way you do it.

Yes the guy I have been dealing with has brought up the idea of path of least resistence so I'm sure he is taking that account when keeping the whole room at a certain temp. The cases for the equipment to house in are designed specifically for high air flow they pull cool air in from the front and side and blow it out the top.

Initially we spoke about ducting the intake right down to beside the machines but he was concerned that it may be better for the computers to do their cooling job by themselves.

I did send him a plan and size of the room. The hot air will blow directly out of the top of the machine. I'm not sure where he will put that extractor fan - probably beside the machines for max effiency I suppose?

Again, his idea is to keep the whole room at a consistent 25 degrees so the thermostat would be measuring this from somewhere??

I suppose I'd have concerns about reducing cost as much as possible so I'm not sure if it's required to keep the "whole" room at the same temp. However, maybe looking at the bigger picture even if it is working over a bigger area it just means the fans will be moving slower as opposed to faster if the area was contained.

euser1984

robbie7730 wrote: »

I wouldnt put fans feeding as well as extracting i dont think, you will just have an air current straight through, and the air wont change as efficiently as just extracting, because with just extracting you are creating a lower pressure in the space which assists in changing most of the air volume every so often.

I would say the ideal setup would be air intake vents in front of the comuters with the computers own intake vents facing the space intake vents, and extract at the opposite end of the space.

A stat set to bring on the extract fan at 25 degrees might work, and adjust it to get the best cycling setup probably.

I am adding options below that were presented to me. I am also attaching the pdf I sent as a plan of the room. I have added the bathroom location also as a possibility of pumping the heat here or the corridor to warm the house.

Option A:
The easiest thing to do in this case is to put one grille on the house to draw fresh air in through via a suitable filter.
And put a simple fan up high in the room to exhaust to the outside.
Any time the room temperature hits 23-24 degrees the fan would be switched on via a thermostat.

Option B:
As above only with 2 smaller fans, one delivering to the room and one extracting.

Option C:
As per option A above with a programmable controller to adjust the fan speed according to the internal and external temperatures. This would provide for an internal temperature at a steady 25 degrees.

antoinolachtnai

Your machines blow towards the back though? Right?

This means they are extracting backwards not upwards, even of fans are at tops of machines.

(by contrast, mainframes have vertical PCBs and as a result ventilate upwards,which requires different ventilation arrangements)

Have you tried this with one fan already? What was the result?

euser1984

antoinolachtnai wrote: »

Your machines blow towards the back though? Right?

This means they are extracting backwards not upwards, even of fans are at tops of machines.

(by contrast, mainframes have vertical PCBs and as a result ventilate upwards,which requires different ventilation arrangements)

Have you tried this with one fan already? What was the result?

I've decided to have another go at getting this to work myself.

My computers cases are designed to blow the air up through the top.

I haven't put any fans in yet. Initially I didn't have the correct computer cases but have now got high airflow ones. I am going to try extracting the hot air again using the Vortice fan I originally got and see if I can now keep the room at 25c or lower.

If that doesn't work I'm thinking maybe to put an intake down near the bottom of the room to let air in from outside.

If this doesn't work I suppose it's either a more powerful extractor or a fan to blow the cool air in? What would be your thoughts on this?

Stoner

well as discussed this is not a type of cooling system that is typically capable of cooling a comms room, but to make the best of the situation I think that it is advisable to concentrate the fans on dumping the hot air as quickly as possible, newer cooler air can find its own way in through vents you have/make it should not need help getting in, but I'd concentrate my fans on dumping the hot air, all IMHO that is.

antoinolachtnai

What sort of cases are these that blow upwards? Do you have a pic or a spec?

I agree, try using what you have got before you buy any more gear.

If you can't get it to cool, I would say to try leaving the door open, that should supply enough cool air. If you then decide to put a vent in the wall, you can do that.

Do you have temperature measurements for this room for when there are no computers running?

euser1984

antoinolachtnai wrote: »

What sort of cases are these that blow upwards? Do you have a pic or a spec?

I agree, try using what you have got before you buy any more gear.

If you can't get it to cool, I would say to try leaving the door open, that should supply enough cool air. If you then decide to put a vent in the wall, you can do that.

Do you have temperature measurements for this room for when there are no computers running?

http://www.coolermaster.com/product.php?product_id=6653

I don't know the temps in the room at the moment but it's very rarely warm - I'd say the majority of the time it's under 20c. The room is 5x4meters and the height is 2.1.

Attached is a plan of the room which shows where the 4 machines will be placed.

I included the bathroom and corridor as I may use the hot air extracted to heat the house.

antoinolachtnai

Is this a render farm? Those look sort of like workstation machines. You're not using them as workstations, are you?

If you blow out to the corridor, you need to provide some ventilation from the outside. (Otherwise you will just be pulling in the hot air you just blew out).

euser1984

Render farm yes. I'm actually going to be getting a pro in to do the job now. However the machines still need more air blown into the side so I was thinking of taking the side off and putting in a box fan.

What do you think of that idea? It's unfortunate that I have to do it. The fan on the side is just 110cfm - I think you can get up to 150 but I'm not sure if that's good enough.

antoinolachtnai

I don't understand why you are using these machines. Have you big graphic cards in them? Or why are they running so hot?

Are they actually overheating?

I would try the big fan extracting to the outside or the corridor and see how that goes before changing the fans or messing with the case.

Opening or modifying the case won't necessarily make it ventilate better. A good box should drag air through the whole case.

euser1984

antoinolachtnai wrote: »

I don't understand why you are using these machines. Have you big graphic cards in them? Or why are they running so hot?

Are they actually overheating?

I would try the big fan extracting to the outside or the corridor and see how that goes before changing the fans or messing with the case.

Opening or modifying the case won't necessarily make it ventilate better. A good box should drag air through the whole case.

12 GPU's in each box. Room was at 18 celcius last night and some GPU's are still running too hot. Optimal temp is below 80c but some gpu's are going right up over 85 - that's even with them clocked down from standard 830mhz to 600Mhz which is a serious waste of power. They should be running at normal clock speed with the potential to overclock if required.

antoinolachtnai

Ah. What does the manufacturer say? Is this a recommended config?

The shape of those boxes might not lend itself to being configured as required.

What is the board layout? i.e., what way are the gpu's inserted? If they are not inserted in a way that will allow the airflow to go past them, then that is going to cause problems. Can you take a photo of the inside of the box?

I think from this description the issue is within the box rather than with the ventilation of the room generally.

It sounds deadly! What are you doing with it?

euser1984

antoinolachtnai wrote: »

Ah. What does the manufacturer say? Is this a recommended config?

The shape of those boxes might not lend itself to being configured as required.

What is the board layout? i.e., what way are the gpu's inserted? If they are not inserted in a way that will allow the airflow to go past them, then that is going to cause problems. Can you take a photo of the inside of the box?

Well it's the standard config. Attached is an picture of a machine with the exact same setup as mine. It comes with a 200mm fan at the side which is 110CFM. The fans do not seem to go much higher than that regarding airflow - noise is not a consideration btw.

antoinolachtnai

Blimey! That is cool! Do you mind me asking what you are using it for?

What kind of graphics cards are those?

If this is a standard configuration, and if the room is reasonably cool, is it not really the manufacturer's problem to figure out the cooling?

Are the GPUs at the bottom faring better than the other ones?

Is the air coming out the top pretty cool?

I think the problem is the airflow design in the box. It's all over the place. There's air flying here there and everywhere and the different flows may be interfering with each other.

My own intuition would be that the fan at the top is pulling cool air away from the graphics cards. As a result, the graphics cards aren't getting enough cool air passing through them and so the chip overheats.

Easy enough to test for this. Try disconnecting the extractor fan at the top. You could also try reversing those fans, so they blow cool air into the case.

The idea I would have is to increase the air pressure inside the case and force as much air as possible through the graphics card.