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Discussion Starter · #1 ·
i've got some muffin fans from Science Plus. They do a good job for such cheap, small things, but one problem. I have not mounted any of them because anytime a part of the fan's enclosure comes into contact with it, it begins to make an irrating vibrating sound. I think you know what I'm talking about. I have used tape, even kleenex underneath to keep it from making noise, but the fan is unstable unless I use screws. There is nothing I can do to prevent noise from the fans vibrating the screws. :x

Are there quieter fans that can be housed with screws that will not make tons of vibrating noise? I mean, the fans I have do a good job, and they are quiet when they are not touching anything, but the only way to get them to stay properly without noise would be to dangle them from a wire. :?
 

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The problem with the cheap fans is that they are not balanced, and not have a ballbearing but a bushbearing. I use foam tape with on boad sides glue. What also can be used is draught tape for doors or windows. I don't now if this is the right word for it.
 

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Discussion Starter · #3 ·
will the "non-cheap fans" say ball bearing on them?

BTW. How are you wiring your fans? I have just used wired nuts, but I think that's a little too big for them. i hook them up to multiple fans, so I can get the most out of my AC adapter...
 
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Go to overclockers.co.uk and youll see that they have 'washers' or spacers for fans made out of rubber, use them. Or get some decent low noise computer fans, Akasa make some amber ones that would be perfec
 
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If you want a quiet fan you are going to need to go with a computer fans. There are a bunch out there designed to be quiet. Also what size fan are you using? The bigger the fan diameter the quieter it will be. You also need to make sure the fan is mounted straight. If it is tweaked a little it tends to rub.

These might do the trick.
http://www.newegg.com/app/ViewProductDe ... 614&depa=0

http://www.newegg.com/app/ViewProductDe ... 602&depa=0

Most fans have a decible level listed on the packaging. Look for the quietest. IIRC you are looking for 20-30 db but i could be wrong.

Here is a link to a gasket.
http://www.newegg.com/app/viewProductDe ... 254&depa=0
 

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Rain_Frog

I have a test vivarium Vivaria style here. On this moment I have built-in 2 pcs 12 volt fans 45 x 45 mm too heat-up the vivarium. In the lighthood there is a 230 volt 80 x 80 mm fan, and on the backside is standing a 230 volt tangential fan. See also my post Air circulation principle Vivaria Paludarium http://www.dendroboard.com/phpBB2/viewtopic.php?t=4731 For the 12 volt fans I have built a PWM (pulse width modulation) fan controller, so I can adjust the speed of the 12 volt fans. The tangential fan is also regulated in speed. I am testing now what the best adjustments are. The major problem is the humidity. Therefore I use a misting system with a seconds timer and also a high frequent mister (Boneco) with an external humidity sensor. (I have take out the internal sensor and made it external) I think it cost my months to figure out how to do, but this is my hobby. If I have some time I and you guys are interested in it I can show some pictures of the used materials. Maybe it is interesting for some of you.

For the 12 volt fans the bal bearing fans are more expensive than those with bush bearings. I think that sleeve bearings are the same as bush bearings.
 

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I would be interested. How did you assemble the fan speed control?

Luke
 
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I am very interested as well.

The way i did it was buy the radio shack transformer that had variable voltage output, i think it was 2-12v. 12 volts tended to be to much and under 5 volts the fan would not start without a push. Im hoping hans has a more sophisticated solution.

Show us what you have hans, i eagerly await.
 
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Also hans how does vivaria.nl align the u channel for the sliding front door? Do you have any closeup pictures of this?

Sorry for the threadjack.

Stitch
 

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Discussion Starter · #11 ·
i have a fogger hooked up to a digital timer, plus a a large dripwall. My tank has one 55 watt power compact over a 20 US gallon long tank. I keep the bulb 4" above the glass. There are no fans. It typically raises my tank temp 2-4 degrees. So, my tank is normally around 78-83 degrees, err, 26-28 Celsius. The humidity is 85-100% (I need a digital humidity meter)

The fogger does a good job...perhaps too good. In fact, I've shut off my fogger to only 4 times a day. It was originally on for 14 times a day, but the plant leaves got too much moisture on them.

However, I cannot get more than 14 settings on my digital timer. Perhaps I could hook up a second one, and have my timer go on at 1 min intervals?

Temperature, humidity, and lighting is the most painful thing to figure out, unless you're willing to put money into a chiller (not worth it in my opinion).

Where do you get a seconds timer here in the US? And what is a high frequency mister?
 

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Sorry. With the high frequent mister I mean the ultrasonic humidifier. In this case I use an external type. I have made the PWM regulation in stead of a linear regulation because of the better regulation in the lower RPM. A 12V dc fan has a minimum torque up to 60% needed to spin, so you can’t do low speed with a linear regulation. A PWM regulator works with a rapid stream of small hard pulses of 12V. The intervals between those pulses are regulated, but it is always an 12V spike. The advantage is that we have always our maximum torque applied when it’s pulsed on, so you can keep the fan spinning very slowly if you do wide pulses that are spread out far apart. I am testing now in a totally dry vivarium without running the back wall, only to see how everything is reacting when I change something.

@Stitch. I have pictures of it and will post them. But I am on my work now. Its 10.00 hour in the morning while I am writing this
 

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Discussion Starter · #14 ·
foggers work VERY well. But the problem is, they dump too much moisture at once, and then make the plants rot, or at least in my experience. Now moss and moisture loving plants, well, they begin to grow like weeds throughout my tank. With a fan turned down on a low speed, evaporative cooling can take place in the vivarium, as long as the humidifier runs constantly....

...That can be a hassle though, the drawback to foggers. If you dont have a big enough resevoir, chances are, you'll be refilling constantly. I assume you would really need the fan/ fogger combination only during the day, as the lights are off at night.

How much do chillers cost in the Netherlands?
 

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Rain_frog,

Because of this problem I have removed the inside RV sensor and make it an outside one that can be placed in the viv. So you can adjust the humidity inside the viv. The humidifier I use can also heat up the water till 80 degree Celsius. It's coming out on about 40 degree. So there is almost no cooling down the air. Of course the heating can turned off. Also the humidity output is regulated. See further the pictures here under.
 

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Here are the promised pictures

The test vivarium


Usable fan types


Fans built in plexiglass inside light hood


Fan detail


The ultrasonic humidifier Boneco


New print with humidity sensor and 2 NTC's


The complete new built humidity sensor wit cable and connector


The PWM print. Left is input 12V dc. Right is PWM output.


My electronic workbench
 
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