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Discussion Starter · #1 ·
Just wondering what fans you guys use or would use to circulate air to vent and cool your canopies?

I can only think of PC fans, but I can't think of how to power them from a wall outlet. Also, better to blow the heat out, or blow cool air in, or maybe in on one side, out on the other? Anybody able to help me out?

Full disclosure: I actually want to vent my entertainment center and not an aquarium canopy, but I figure its the same concept and you guys might be able to help me out.
 

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K.. PC Fans are the way to go IMHO. Get u'rself a Power supply from an old phone or something like that. do a couple quick solders and your all set!!

Or do what ever you want LOL.. that's just what I'd do
 

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Since old computers are so throw away priced, I would look for one to tear down. That gives you both the fan and the power supply. Good chance you can get a broken/obsolete one free on Craigslist if you will haul it. I would go for sucking the air out and letting it come in the other end.
 

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Hmmm... I am no expert on electronics but I do know that if you put one fan to blow air in, it would bring dust along with cool air. Now, dust plays a major part (from what I have experienced in computers) in keeping heat in, so the more dust that there is available to go into your electronics, the warmer it will remain. I would just use one fan to blow the warm air out and see if that gets rid of the problem you seem to be having, otherwise use two fans but you will need to clean your electronics regularly for dust accumulation (compressed air works well for quick dusting of electronics).
 

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Air flow being pulled across an object works better at removing heat than airflow being forced over an object.

Problem is most canopies are open to the rear so getting proper flow would mean baffles or locating the fan(s) over or near the heat sources(s).
 

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Dust probably will not be the major problem on a tank that it is in electronics. Not much static to collect dust and the fan itself will take a large amount of dust before it becomes a problem. For directing the airflow, a simple cloth shield hung down over the back will do the trick of making air flow across the width of the canopy if needed. As a simple first step and to keep from cutting a lot of canopy, I would start with hanging a fan on back to shoot air into the back of my canopy. It is almost all open but air blowing into the opening on one end will often force air out the other. Enough to cool for lots of situations. Just getting air exchanged may be enough.
 

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Discussion Starter · #7 ·
Thanks guys. I think I can canabolize my wifes old dell computer and hopefully get a couple fans out of it. I also have my neighbor's old PC hanging around because they never asked for it back the MoBo died (I was trying to fix it for them) and just bought a new one, so maybe I can get a couple fans out of there too. I understand I need a 12V power supply, with enough amps to go around. I've read on other sites that you can get such things at radioshack, and just attach the fans so it can plug into an outlet.

So that covers the equipment and I guess thats as far as it goes in relating to a canopy I guess. I planned to try to blow heat out through the top back of the entertainment center and draw in cooler air through the loose fitting front doors, and hopefully that will be good to keep the air in the EC cool. Just need to make sure its not going to pull the cool air in and not right back out and leaving all the hot air in there stagnant, or even worse blow the hot air out and suck it right back in through the cable holes in the back. So, similar to what you guys are describing with regards to the canopy. So may I can consider blowing cool air from the outside into the top, and forcing the hot air out wherever it wants to go, but then I do have to deal with the dust problem since my application is for electronics. Or maybe one fan blowing in low one fan blowing out high would do a good job of making sure the hot air gets out by controlling where the cool air comes in.
 

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You may want to take a look for sure before going for the 12V supply. I've not torn down that many but I could imagine some on other than 12Volts. With the computer there should be a ready made power supply as well as the fan?? The one I tore down had a small modular piece for the various voltages and it made it very easy to just slip it off and I was sure it would match the fan.
For location, mounting the fan bottom or top may not make that much different. In industry, it is pretty common to let cool air in low as it tends to travel up by nature but in small home type stuff that may not matter as much as ease of mounting the fan. In houses there is more dust from floors down low rather than higher.
 

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I have done this using a muffin fan. Same thing as a pc fan we use them at work to cool circuit cards during test. I just crimped the right size fitting to an regular cord from a house hold appliance and connected to fans. Then mounted them accordingly flow outward to pull hot air out and draw cool air in.
 

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New fans are dirt cheap if there is a major computer store around and you can get sizes from 40mm to 240mm. The most common size, 80mm, can be purchased for as little as $1 if you watch for sales.

These fans are 12V DC and you can use a lower voltage if you don't mind the fan running slower. Slower means quieter when dealing with fans.

Those with a molex connector use only two wires - power and ground. Those with a motherboard fan connector use two, three or four wires. The additional wires are speed reporting and speed control. Molex connectors are large, flat and have large nail shaped pins inside. These are male connectors on the fan wire. Motherboard fan connectors are smaller, more rectangular, and most important, have female connectors on the fan wire. These accept smaller pins, about the thickness of a paperclip.

As to using the power supply from a PC to power the fans - not a good idea on a couple of levels.

First, the power supply is turned on and off by the motherboard of the computer via a control signal sent through the 20/24 pin power connector. It could be possible to wire this out of the unit but then you have spent more time and effort than it would have cost to buy a AC to DC adapter.

Second, even a small power supply is rated at 150 watts or more (can be a lot more, my systems run at 500 watts minimum). Most idle at 40-60 watts and put out a lot of heat. The power supply itself could get hot to the touch.

Third, a computer power supply is grounded in the case. Do not open the power supply as it contains large capacitors that can discharge weeks or longer after the unit has been unplugged. These caps are large enough to injure by shocking or burning. Do not try to salvage the fan or fans from a power supply, these fans are usually worn down or beat up from constant running in a high heat environment plus the attracted dust gets in the bearings.

Now - if you do have a old or dead PC power supply, that is a good place to salvage the wire and connectors for hooking up your fans. Just cut them off.
 

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So we should always just throw things in the trash and not try to reuse it? Seems like a pretty good way to run out of what little we have left. Have you noticed we are about out of things in this country? It does take some time and effort but we better start thinking before we are totally out.
 

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Discussion Starter · #12 ·
Yeah sorry for the confusion guys when I said I'd get a 12V power supply I meant a 12v ACDC converter like this (random search result, I've heard they're available at radioshack but I couldn't find them online): http://www.amazon.com/12v-Power-Adapter ... B003B24LRM

I would cut the plug off and hardwire the fans to the plug and let them run 24/7 as I've got a cable DVR box that's always emitting some heat day or night anyways.

I didn't mean to use a computer power supply I know those give off a lot of heat.

As for fans I'll look into muffin fans but if I have 3-4 free PC fans I can pull out of old PC's they might just do the job.

I'm not too worried about the noise. The fan noise will have to compete with the sump for my 125 which is sitting in the living room. Who's taking bets on which will win :D
 
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