# Tiny tiny fan



## mellowvision (Feb 6, 2009)

I just found this computer fan for 59 cents, so I thought I'd share it with the crowd. Just Cooler FC-900L Expansion Slot Sleeve Bearing Case Fan w/4-Pin Connector (Black) - No Bracket Just Cooler FC-900L

But really, I'd like a much smaller fan, that I can mount behind the trim on my marineland tank. The trim is deep, so it would be nice to use the space, since I can't see there from most views. The available space is about 1.25" -1.5" depending on how you look at it. I've seen fans as small as 40mm x 10mm. I'm curious if you've got opinions on what to look for in a fan. Also, are there any specific precautions I should take with running the fan in high humidity? Controllers you love?

here are 4 that caught my eye http://www.acousticpc.com/quiet_40mm_computer_fans.html


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## Chris155hp (Mar 17, 2010)

I would look for as larger thin fan as they can produce more airflow while producing less noise. I actually was planning something for my vivarium


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## slipperheads (Oct 17, 2007)

I look at noise level more than anything (db). The lower, the better. Power is a big deal to me too, but all my fans are connected to adjustable AC/DC converters, so I can control the air speed using a switch.


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## mellowvision (Feb 6, 2009)

so what db level is acceptable to you?


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## ryan10517 (Oct 23, 2010)

the 80mm cooling fan i have on my light fixture is rated at 30dB max. i really don't notice it when i'm in the room. I don't think i would want anything louder than that though. its rated at 34 cfm too


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## hexentanz (Sep 18, 2008)

For those worried about noise from fans, you can also use vibration dampening kits along with these, as they really do help.

I have to keep my computer on my desk and use ultra silent fans along with vibration dampening kits. You cannot even tell my computer is on if you do not look for the lights at the front. 

I also apply these kits to all my racks where I have fans and you cannot even hear them going.

dba levels should be 25 or less for ultimate quietness.


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## mellowvision (Feb 6, 2009)

the little ones in the link above seem to be in teh 18db range, with 5-6cfm. I realize it's not a lot of flow, but seems a lot quieter than 30db. Although, I don't know what the difference of 15db sounds like. Gotta say, it would be nice to be able to hide something so small in the tank. I'm primarily looking for enough flow to just keep the glass from fogging. right now, I find that if I prop the front of the lid open 1/4" across the whole front, the glass does not fog, and the humidity loss is generally 10% of what it was... but I'd prefer not to have so much open. I wonder if one in each corner would be enough. 

is there a speed controller you prefer?


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## james67 (Jun 28, 2008)

i use delta fans (40mm) that can push 24cfm. they are rated at 54db, but with a controller, its easy to get them just where you want.

james


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## mellowvision (Feb 6, 2009)

circuit city had a good price on the silenx 4 channel controller with ac adapter, and silenx 40x10mm 5cfm fans... I got 4. I realize 5cfm isn't much air, but I really don't need much flow, and if I have to return them, circuit city makes it easy. They are super silent fans too, so I'm thinking I can run all 4 if I need to.


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## mellowvision (Feb 6, 2009)

Well, ok. 4cfm isn't quite enough with 2 fans, and I don't want to run 4, so I'm looking for a couple of stronger fans. I'm having a hard time finding 40mm x 40mm x 10mm fans with much more than 5cfm... it seems like you get about 5cfm per 10mm of thickness as you go up. Delta 40x40x28's get around 15-18cfm... 

So the question is, what's a good specific model to look for? I'd really prefer a 20mm fan, to keep it small and light weight... but will 10-12fcm be enough? hard to tell. 5 wasn't.


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## mellowvision (Feb 6, 2009)

ok, so today I received 3 delta 12v fans to replace the tiny silenx fans I had originally purchased. The new fans are 40mmx40mmx28mm and really pack a punch, at 24cfm. They are not as quiet as the tiny ones, at all. At full speed, they are quite noticable even in the tank. But, they do not need to operate at full speed. A single fan is currently keeping 80% of the glass clear, on a very low setting.

Had I known this would be the case, I might have gotten the slightly cheaper, slightly slower 15.8 cfm fans that delta makes in the same size. These are quieter, and have a slower top speed, but that would be fine, since I will never need them at top speed. I've got them down around 20% speed, and the one fan is causing noticable movement in the plants, and clearing a large glass area. I can only imagine 3 fans is going to be overkill, possibly even on the lowest setting.

for anyone interested, here are links to the 2 fans I'm talking about, the ones I got and the slower ones...
Delta 40mm x 28mm Fan (FFB0412SHN-F00) - FrozenCPU.com

Delta 40mm x 28mm Fan (FFB0412VHN-F00) - FrozenCPU.com


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## slipperheads (Oct 17, 2007)

For my in-tank circulation project, I use a PVC reducer to house the fan, connected to an elbow funny pipe that leads up to a hole in the glass lid of my tank. To take advantage of the power of a 60mm fan, despite the reducer only able to fit a 40mm fan, I sand the corners off and it fits perfectly.


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## Uniceros (Mar 19, 2011)

But where do you get funny pipe fittings? I asked at home depot and they looked at me like I was making things up to mock them.


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## LookinRound (May 1, 2011)

§lipperhead said:


> For my in-tank circulation project, I use a PVC reducer to house the fan,


What size reducer do you use?





Uniceros said:


> But where do you get funny pipe fittings? I asked at home depot and they looked at me like I was making things up to mock them.


I was just at home depot today and saw them back with the sprinkler system setups (near plumbing for toilets and all that jazz).


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## slipperheads (Oct 17, 2007)

Funny pipe is a common term used to describe sprinkler system fittings. You'll need an elbow and a barb, 1/2". You will also need a cap on the elbow, but I can't find any so I just walk to the pvc section and pick up a 1/2" pvc cap. The reducer I get is a 2 to 2 1/2" reducer. I paint both the reducer and the cap black.


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## bristles (Jan 19, 2011)

Do you folks use the fans on timers ? or do they run 24/7


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## Uniceros (Mar 19, 2011)

I ended up using a PVC fitting from the toilet parts aisle, it was called a trap adaptor I think. It looks like a reducer, and fit right into a PVC elbow that I plumbed inside my clay background all the way underneath the false bottom. It holds a 40mm fan. Ill keep this in mind when I build my first dart tank next week.


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## gex23 (Apr 15, 2008)

I use a low noise 60mm fan, screen meshed over the front / back, strong neodymium magnet siliconed onto am extension off the fan, with the second magnet on the outside of the glass effectively clamping it in place, ran at 9V using a variable voltage adaptor.


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## PeanutbuttER (Jan 1, 2011)

gex23 said:


> I use a low noise 60mm fan, screen meshed over the front / back, strong neodymium magnet siliconed onto am extension off the fan, with the second magnet on the outside of the glass effectively clamping it in place, ran at 9V using a variable voltage adaptor.


That's smart using a magnet. Do you have a picture of it? How strong of a magnet did you need?


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## james67 (Jun 28, 2008)

mellowvision said:


> ok, so today I received 3 delta 12v fans to replace the tiny silenx fans I had originally purchased. The new fans are 40mmx40mmx28mm and really pack a punch, at 24cfm. They are not as quiet as the tiny ones, at all. At full speed, they are quite noticable even in the tank. But, they do not need to operate at full speed. A single fan is currently keeping 80% of the glass clear, on a very low setting.
> 
> Had I known this would be the case, I might have gotten the slightly cheaper, slightly slower 15.8 cfm fans that delta makes in the same size. These are quieter, and have a slower top speed, but that would be fine, since I will never need them at top speed. I've got them down around 20% speed, and the one fan is causing noticable movement in the plants, and clearing a large glass area. I can only imagine 3 fans is going to be overkill, possibly even on the lowest setting.
> 
> ...


i see you got those fans. 
i swear by them and they are the only 40mms i use.

james


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## LookinRound (May 1, 2011)

§lipperhead said:


> The reducer I get is a 2 to 2 1/2" reducer. I paint both the reducer and the cap black.


ok, that's what I've been looking for but have been unsuccessful thus far. I have checked Home Depot, Lowe's, Jerry's, a local plumbing store. No one seems to carry 2 1/2" of much of anything if at all...


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## mellowvision (Feb 6, 2009)

I just wanted to comment on this: 



gex23 said:


> I use a low noise 60mm fan, screen meshed over the front / back, strong neodymium magnet siliconed onto am extension off the fan, with the second magnet on the outside of the glass effectively clamping it in place, ran at 9V using a variable voltage adaptor.


I've experimented with using magnets in the mounting of the fans, and can say that magnets absolutely have a negative affect on fan speed. In fact, in some of my tests, the magnet would keep the fan from riding correctly in it's track, so it was always pulling towards the magnet, and in other cases, the magnet would keep the fan from starting up at all, even under full power. In all cases, the magnets slowed the fans considerably. I've tried this with a few magnets and a few fans.


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## gex23 (Apr 15, 2008)

mellowvision said:


> I just wanted to comment on this:
> 
> 
> 
> I've experimented with using magnets in the mounting of the fans, and can say that magnets absolutely have a negative affect on fan speed. In fact, in some of my tests, the magnet would keep the fan from riding correctly in it's track, so it was always pulling towards the magnet, and in other cases, the magnet would keep the fan from starting up at all, even under full power. In all cases, the magnets slowed the fans considerably. I've tried this with a few magnets and a few fans.


When I attached the magnet directly to the fan, yes it affected the fans ability to spin up and start on its own. However now i've put the magnet on an 'arm' away from the fan (a few cm) the fan starts every time (right down to 5v), with output being as expected and more or less completely silent.


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## FwoGiZ (Jul 8, 2008)

all you guys using that reducer technique to encase the 40mm fans, are you using 40x40x10 or x20? does it make a difference?

I am still wondering if I should put my in-tank air circulation fans on a schedule or leave them on 24r. I am looking for 5-8CFM fans and no higher than 24DB.


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## slipperheads (Oct 17, 2007)

The sceduling is up to you I guess. If you were rigorously misting to induce breeding for a "rainy" season, having them on 24/7 might be necessary. If you are questiong whether or not the fans CAN TAKE the 24/7 schedule, don't worry, they are more than able.


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## mellowvision (Feb 6, 2009)

I found great parts at Pepboys Autoparts today, that allowed me to attach the fans to the glass with a single screw, and have 360º swivel and pivot. The whole thing cost about $4 per mount, including the telescoping mirror, rubber washer, and metric machine bolt. But now that I am testing out the set, I realize the fans are too strong. I would like to dial them down below the low speed... these fans are just too fast at 24cfm top speed. I'm going to step down.


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## mellowvision (Feb 6, 2009)

here's a couple of pics.


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## mellowvision (Feb 6, 2009)

also, @FwoGIZ:

I have silenx 5cfm fans that are pretty much dead silent, that I am also not using, PM me if you are interested.


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## slipperheads (Oct 17, 2007)

mellowvision said:


> here's a couple of pics.


The reason why I am making mine with the reducer is to make it more durable and established. Plus I don't want to run the risk of dicing my frogs up!


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## mellowvision (Feb 6, 2009)

you could just add window screen to this and make it as frog safe... mine do not have any chance of frogs getting in, so it's not a big deal. This design allows me to swap out a fan with a single screw, and doesn't require any modification to the fan or the part, so it's just way simpler. I like how some of the reducers look, but since my fan is not visible from most angles anyway, I don't need it. It's just extra work.


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## james67 (Jun 28, 2008)

i use SS woven wire cloth and laser cut brackets to hold it in w/ screws.

wire is available in any number of configurations at 
McMaster-Carr

james


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## frogparty (Dec 27, 2007)

James, as an ID student you probably have access to tons of cool tools for viv construction


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## mellowvision (Feb 6, 2009)

Now that i've run this for a day, I think these fans are way too powerful for the controller. After 12 hours, the knobs are hot to the touch. I think it's just a little too high wattage for it to handle. 

For people looking to see how the silenx 4 channel controller handles 24fc fans, I'd say think again, the speed is too high, the sound is too loud, and it generates unsafe heat. At least, these Delta .6amp fans are too much for it.


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## james67 (Jun 28, 2008)

ive graduated, but i still sneak into the building when i dont have the tools i need. 

james


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## james67 (Jun 28, 2008)

im fairly sure its a flaw with that controller unit. its pretty common, from some of the reviews ive read online. the components used in its construction are apparently not sufficient to run the fans, even though the spec sheet says they can handle much more. the fans are .6A ea, and if i remember correctly your controller says it can take 1A on each channel, but actually has trouble with anything above like .4A.

james


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## mellowvision (Feb 6, 2009)

Hey James, thanks for that. I was assuming that was the case, I will try to keep it under .4amps with new fans.


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## FwoGiZ (Jul 8, 2008)

What about the 40x40x10 or x20? does it make a difference?


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## james67 (Jun 28, 2008)

yes. its the depth of the blade and therefore the fan has more surface with which to push the air.

james


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## mellowvision (Feb 6, 2009)

right, you'd be hard pressed to find a 40mm x 40mm x 10mm fan with anything faster than 5 or 6 cfm. the blades just don't have the surface to push much air.


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## FwoGiZ (Jul 8, 2008)

I guess my question is more like, is 10mm enough? or should i go with 20mm?
I want to be able to encase these in pvc reducer to make some neat job


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## mellowvision (Feb 6, 2009)

I tried a 10mm fan that runs at 5 cfm and it was nowhere near fast enough. 

So I tried a 28mm delta fan at 24 cfm. The was too fast, and too loud, and started burning out the controller. 

The catch: the 24cfm fan I linked from frozen CPU says .4 amps on the site but he fan I received was .6 amps. Thecontroller says it can handle it but it can't. I sent everything back in favor of reordering more compatible components.


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## james67 (Jun 28, 2008)

you also payed a bit high on the fans, if you bought them from the site you linked. with a good controller or variable voltage wall wart, they are excellent.  delta makes several varieties of this fan with different ratings:

http://www.delta.com.tw/product/cp/dcfans/download/pdf/FFB/FFB40x40x28mm.pdf

james


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## mellowvision (Feb 6, 2009)

hey James, can you recommend a store to order both a fan and controller from? I would have probably kept the fans and returned just the controller had I read your post just now, but I already mailed them this morning. So now I have an empty slate.


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## Heartbreak7 (Mar 26, 2009)

mellowvision said:


> I found great parts at Pepboys Autoparts today, that allowed me to attach the fans to the glass with a single screw, and have 360º swivel and pivot. The whole thing cost about $4 per mount, including the telescoping mirror, rubber washer, and metric machine bolt. But now that I am testing out the set, I realize the fans are too strong. I would like to dial them down below the low speed... these fans are just too fast at 24cfm top speed. I'm going to step down.


What are those pep boys parts called/what section of the store did you find them in? Seems like a cool minimalist solution. How is that mounted?


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## LookinRound (May 1, 2011)

Heartbreak7 said:


> What are those pep boys parts called/what section of the store did you find them in? Seems like a cool minimalist solution. How is that mounted?


The one thing I noticed with that setup is the wire for the fan has to go out some other location, which did work for his setup. Just something to keep in mind.


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## mellowvision (Feb 6, 2009)

this looks like the exact item I cannibalized. 

Amazon.com: Telescoping Magnetic Pick-Up Tool with Mirror 27": Home Improvement

at the autoparts store, they were 2 bucks. I drilled a 5/16" hole in the front of my hinged glass lid for the bolt through, with a rubber washer and a black metric cap bolt. On the male threaded end of the ball joint, I used that to thread into the plastic of the fan housing. I threaded the original hole using a matching thread bolt heated up a little bit. It was pretty easy. I had nicely sleeved cables, and ran them through the plastic hinge. I wanted to be able to quickly remove the fans if needed, and wanted the smallest, least build time solution I could find. 

I'm still looking for advice on a better place to shop for the fans. I'm still on the fence whether I want to use the 4 channel silenx controller, or a single channel controller with a split to 2 fans. The silenx is a lot easier, but I'm concerned about finding a powerful enough fan that wont burn out the controller.


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## mellowvision (Feb 6, 2009)

no advice James? Been waiting to hear back


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## james67 (Jun 28, 2008)

sorry. 

i havent found a site that carries both a 40mm fan (of a quality brand) AND the power supply, but heres a site that has a good fan that produces 9.6 CFM while drawing only 0.1A. 

Delta AFB0412MA 40mm Fan - 40mm Fan

a power supply is easy to find. 
this one can supply 4-5 fans and its $6

Enforcer 12V DC 0.6A Power Supply - ST-UV12-S0.5Q - Smarthome

this one can supply 16 or 17 of the above fans and its $7

Amazon.com: Microseven Power Supply 12V DC 2A for CCTV (CE UL) Power Led: Electronics

anywhoo, sorry about the wait. if you have any more Qs ill do my best to answer
james

edit:

heres a fan controller from a company that has pretty good reviews:
http://www.amazon.com/Lamptron-Speed-Controller-channel-Black/dp/B002R8IZAA


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## mellowvision (Feb 6, 2009)

Hey thanks James, I appreciate the links. I'm curious, do you think the Silenx controller should be avoided all together? I do like that it is contained and doesn't require additional soldering or housing... but if you think it will continue to be a problem, the drive bay style controller is within reason for me.


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## james67 (Jun 28, 2008)

id continue to use your silenex till it has problems. it may be fine. i was under the impression you already returned it. 

soldering is easy, and its something ill be covering in the video, (when i get a chance to make it) i actually just finished soldering the circuit boards (ballasts) for a dual T8 fixture for my GF's aquarium.


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## mellowvision (Feb 6, 2009)

I did return it, but only because I felt that it had burned out and was acting erratic after being used within the specified ratings... I don't mind getting another one, and pairing it with lower amperage fans, if it will work. But since I now have no fans or controllers, I'm starting with a clean slate, and can get whatever makes the most sense. Ideally, I'm hoping for 2 fans that run around 15cfm and are under 40db at full speed and a controller that can vary them independently.

I'm fine with soldering, very comfortable with it. The attractive part of the silenx is the simplicity and small size really.


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