How to lower the noise of the DC fans

[husky]

I just bought a set of cooling fans (those 4 in a row type). Started it on my tank and the noise level is abit high but as it's my tank, thus tolerable to me But my mum started complaining after coming back. Is there any way to lower the noise level (besides getting a chiller which is very tempting )? Any suggestion or advice? Thank you in advance

[bluezing]

how much u buy the fan for?

[husky]

I got it for $60 from petmart. Brand is "Ocean Free"

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On 8/22/2003 11:17:21 PM

how much u buy the fan for?
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[hwchoy]

you sure it is DC?

[bluezing]

oh yah...dun tink those are DC,cos u just plug them in rite?no need convertor....hehe.easy yah?no need DIY.i just bought one AC fan at SLT today.12cmx12cm.can save quite alot.

[husky]

Oh no, I have to attached the plug to a transformer before starting the fans.. How do you guys differentiate what is not a DC fan? I am not a DIY person, if not, I would have went to SLT to get the fans too (imagine the savings!)

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On 8/22/2003 11:36:37 PM

oh yah...dun tink those are DC,cos u just plug them in rite?no need convertor....hehe.easy yah?no need DIY.i just bought one AC fan at SLT today.12cmx12cm.can save quite alot.
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[nbk3]

AC u cannot vary the voltge :P and if it gets too loud , u can always lower the voltage for a DC fan []

[nbk3]

AC u cannot vary the voltge :P and if it gets too loud , u can always lower the voltage for a DC fan []

[husky]

Can't seem to find the voltage control as you have mentioned. The fans are basically plug and play.

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On 8/22/2003 11:45:00 PM

AC u cannot vary the voltge :P and if it gets too loud , u can always lower the voltage for a DC fan []
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[bluezing]

oh if u use a transformer...then yes...DC oredi.AC are those plug and play type.no need transformer one.i have seen this oceanfree fan set b4.erm...i can say...for 4 fans and the cover everything...is EX.imagine u can get 4 fans at SLT for like less than $15.(of that size that is)

im also not really a DIY person.but bo pian.times are bad.haha...so i went out and got one today.worth it!!!

[husky]

The cost was putting me off initially but the welfare of my pets was more important so *sigh* Even the *papa* dun have air con in the house

I have been to SLT and the price is real Cheap but got no idea how to hook it up to my tank. How did you do yours? Is it possible to share with me?

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On 8/22/2003 11:56:59 PM

oh if u use a transformer...then yes...DC oredi.AC are those plug and play type.no need transformer one.i have seen this oceanfree fan set b4.erm...i can say...for 4 fans and the cover everything...is EX.imagine u can get 4 fans at SLT for like less than $15.(of that size that is)

im also not really a DIY person.but bo pian.times are bad.haha...so i went out and got one today.worth it!!!
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[bluezing]

yeah...i know.i was tinking of whether to buy the $30 profantech fan anot actually.then that day i removed my top filter...realise that i can use the base support(from the OHF) for the fan!haha...so i measured the width and its ok.cant really fit it in.but gd enuff to put it slanting.and there are 2 big square lobangs.just nice for the wind to blow thru.

*but the problem is...if i sell my ohf...then i gotta buy another type of support liao.[:]

[chua]

Hi husky.

I also brought the ocean free 4x DC fan.When i put in on my tank, the noise is very disturbing.

Hence i took it to my friend's house who is using the normal $30 AC fan to compare the noise level.

Although a lot of people said that DC fan is less noisy as compare to the AC fan, we do not think so.

The AC fan is slightly louder but of lower pitch, whereas the DC fan is not as noisy but of a much higher pitch. It sounds as if there are thousands of bees flying around in your house. Hence conclude that the $30 AC fan is more tolerable.

Hence, i went back to the shop to change. Since the AC fan is out of stock, i managed to get back my money. Lucky me.

But do you really need a fan?

[alweek]

ok... speaking as a computer diy nut here

when you talk about dc or ac fans, there is no hard and fast rule that "ac fans are noisier, etc" not a useful comparison. both AC and DC fans can be noisy or quiet. it depends on many factors such as design, etc. but the main factor is the RPMs of the fan.

if you want quiet fans, generally go for the larger ones. I personally used 120mm x 120mm fans from sim lim tower for cooling my computer. the benefit of big fans is that they move more air AND spin at a slower speed than the smaller fans. they produce less air pressure than a smaller, faster spinning fan but that does not matter if all you want to do is blow at the water surface.

when you buy a DC fan, most probably you'd go for a 12V model. i won't go into details on how to hook it up. just identify the positive and negative terminals. if you power them using a dc adpator, some of these have a selector knob to switch 12V, 7.5V, 5V, 3V, 1.5V. Run the fan at 12V to see how the noise is. If too loud, you can drop the voltage to about 5+volts minimum to see how the noise is. any lower and the fan may not start spinning when you turn on.

120mm fan from sim lim can cost about $8-12, if you are really hardcore, can go for a brand of fans from germany PAPST. very well made and quiet but expensive, expect to pay about $20-30 for a papst...

hope this helps.

[husky]

True, very true. I was under the influence that DC fans are quieter than AC and that decided for me which one to buy. Imagine my shock at the amount of noise produced! But after running the fans for the past 5 days, the noise has become softer (or I am getting used to the noise hee) But mom's nagging is *whew* wahhhaha

So my conclusion is that, it is not always the case that DC fans are quieter than AC. So have you purchased your AC? I definitely need a fan as my tank temp can go as high as 32 degrees. I can't afford that kind of temperature as mine is a SW tank. [:]

Cheers
Kevin

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On 8/23/2003 2:22:50 PM

Hi husky.

I also brought the ocean free 4x DC fan.When i put in on my tank, the noise is very disturbing.

Hence i took it to my friend's house who is using the normal $30 AC fan to compare the noise level.

Although a lot of people said that DC fan is less noisy as compare to the AC fan, we do not think so.

The AC fan is slightly louder but of lower pitch, whereas the DC fan is not as noisy but of a much higher pitch. It sounds as if there are thousands of bees flying around in your house. Hence conclude that the $30 AC fan is more tolerable.

Hence, i went back to the shop to change. Since the AC fan is out of stock, i managed to get back my money. Lucky me.

But do you really need a fan?
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[husky]

I think I have seen papst somewhere .. some reviews on the net hmmm.. But the only thing that is going to stop me from purchasing that, is my lack of DIY knowledge.. sigh ..

Think your explanation has dispel the belief that DC fans are quieter than AC .. hee

Cheers
Kevin

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On 8/24/2003 12:32:50 AM

ok... speaking as a computer diy nut here

when you talk about dc or ac fans, there is no hard and fast rule that "ac fans are noisier, etc" not a useful comparison. both AC and DC fans can be noisy or quiet. it depends on many factors such as design, etc. but the main factor is the RPMs of the fan.

if you want quiet fans, generally go for the larger ones. I personally used 120mm x 120mm fans from sim lim tower for cooling my computer. the benefit of big fans is that they move more air AND spin at a slower speed than the smaller fans. they produce less air pressure than a smaller, faster spinning fan but that does not matter if all you want to do is blow at the water surface.

when you buy a DC fan, most probably you'd go for a 12V model. i won't go into details on how to hook it up. just identify the positive and negative terminals. if you power them using a dc adpator, some of these have a selector knob to switch 12V, 7.5V, 5V, 3V, 1.5V. Run the fan at 12V to see how the noise is. If too loud, you can drop the voltage to about 5+volts minimum to see how the noise is. any lower and the fan may not start spinning when you turn on.

120mm fan from sim lim can cost about $8-12, if you are really hardcore, can go for a brand of fans from germany PAPST. very well made and quiet but expensive, expect to pay about $20-30 for a papst...

hope this helps.
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[hwchoy]

any specific shop in SLS selling this PAPST fan? Don't mind replacing my computer fans if it is really quieter.

[theodore]

Haven't tried 120mm x 120mm 12VDC fans but the 80mm x 80mm 12VDC 0.13A ones (Power Logic brand) I'm using currently are rather quiet.

The new ones (80mm x 80mm 12VDC 0.08A, Evercool brand) I bought recently are even better (i.e. quieter) though I'll be waiting until my old ones die on me before I put in the new ones ...Bought them so that I can hook up 4 fans to my 0.4A adapter.

[joe]

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On 8/26/2003 9:04:17 PM

any specific shop in SLS selling this PAPST fan? Don't mind replacing my computer fans if it is really quieter.
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hwchoy, you can try 3rd floor Kaichin ... got another shop nearby dunno the name ... facing Kaichin just walk along the right corridor till you see a shop with lots of fans neatly stacked on the left hand side of the shop ... they should carry Papst ... power fans with a tolerable noise level (at least not high pitch) ... good luck searching!!! ... i got mine imported from Germany the last time round

[alweek]

ok. a bit of background of myself. i am/was really into computer modding a few months ago. my aim was to build a dead-quiet computer just for the heck of it. i now have a water-cooled computer
however, when it came down to cooling fans, i managed to identify quite a few brands/models that were very quiet (by checking the individual specs from the websites) only problem was, none of the local agents/distributors brought in the specific models i was looking for ("minimum order to bring in : 100pcs&quot

one way i got around this was to use the "7 volt trick" do a search for that on google to learn more about this commonly used technique.

What the 7 volt trick is basically running your 12V fans at less than 12V.

this is used by computer modication people (modders) to lower the RPMs and noise level of the fan. For aquarium applications, this can be easily done by you guys who get those type of AC/DC adaptor with a selectable voltage (eg 12v, 7.5v, 5v, 3v, etc)

experiment, but i'd recommend you don't go below 5V, if not the fans may not have enough power to start.

of course, lower rpms = lower noise = less air, so your cooling rate may suffer... but try it out and see how you go.

some decent brands of fans to try eg. Panasonic/Panaflo, Delta, Papst.
i would recommend you all consider only 120mm fans, maybe 92/90mm if you really want. 80mms need to spin quite fast to give you a decent airflow which equals noise
PAPST can be gotten from Kaichin on 3rd floor and another shop on 3rd floor.
DELTA can be gotten from ASK computers
PANASONIC/PANAFLO can't remember, but they are pretty decent.
NMB/Nimibea are pretty ok too.
SUNON is another well known brand
if you die die want 80mm fans, basement got one shop selling SUNON KD1208PKS3 quite cheap, they spin quiet but don't push a lot of air. if you do use these you need quite a few.

note: when getting fans, don't bother getting those with speed or temperature control. unless you're gonna install them in your computer