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Discussion Starter · #1 ·
Hello,
I'm starting the build for my 65g Peninsula :D. I have the tank and I'm currently building the stand, but other than that most of this is still in the planning stage. The main thing I am having trouble with is internal air circulation. I have a few questions pertaining to it...
1) How many/What size computer fans should I be using? Is there a rule of thumb?
2) How should I place them in the vivarium? Like Grimm's Peninsula setup? Or just mounted to the walls?
3) How do I power them? I've seen James's video but I'm still left a little confused. If someone could point me to a good thread about making a set up it would be greatly appreciated.

Any help/advice would be great. Thanks!
 

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I've not put any active circulation in a viv yet, but I can share some thoughts about it.
No absolute rules of thumb that I know of.

-I'd use DC fans. Their speed can be controlled easier. Older computer power supplies make good power sources and can usually be had for free. Plenty of fan controllers out there. Old cell phone chargers can work too. You'll have to check the fan and charger ratings.

-I'd mount the fans in a location where they can be replaced. They're generally not designed to operate long, in humid environments. There are fans out there that are, but they're more expensive and a little harder to find.

-If inside the viv, they'll need screens to protect the froggies from the spinning blades of death.

-Test before you build/mount. Most DC fans can run pretty slow and it doesn't take much to get the benefits. For DC motors/fans, speed is directly related to voltage, kinda.

-Some people mount them in a PVC pipe with the ends screened, then hide the whole thing.

Passive circulation is another option to consider. All it takes is a temperature differential. Consider just using a big vent with more misting.

Let us know how you go.
 

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Discussion Starter · #4 ·
Thanks for the advice Eric. Greatly appreciated. I plan on using this fan for air circulation. I was wondering how many I need, though. They are fairly expensive so I'd only like to purchase 1 or 2 if that will work.

Also, what can I use to power the fans? I will be plugging them in into an outlet and would like for them to be adjustable.

Thanks for any more help!
 

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mitch i have 14 or so of the these (got them for $3 or so from newegg, sometimes they are cheap, sometimes they are expensive... i dont get it?)


look around the house for these


if you can find one thats has an output: 12v then the mA depends on the fan and fan quantity.
 

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How is a cell charger used...? And how does it "hook up" with a computer fan??? I sure wouldn't want to electrocute any frogs...
 

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its ok im an engineer ;) no frogs will be harmed in the making of this.


see where it says output:12V 1000mA
that means this will supply 12V up to 1Amp of (1000mA=1A) these fans will specify their mA and you want a supply that is 10% greater than that #. if you have two fans the supply needs to be 10% greater than the sum of the two fans.
 

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Also that is a 40 mm fan that is only 1.5 inches. I installed an 120 mm and after I wrapped with one layer of screen the airflow was drastically reduced, I even cut out small sections of the screen to try to help recover some air flow.



Sent from my iPad using Tapatalk
 

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Discussion Starter · #11 ·
If you cover in screen expect a substantial loss of air flow volume!


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I've heard this before. Thanks for the info.

mitch i have 14 or so of the these (got them for $3 or so from newegg, sometimes they are cheap, sometimes they are expensive... i dont get it?)

look around the house for these

if you can find one thats has an output: 12v then the mA depends on the fan and fan quantity.
Do you have a link to what fan that is? Also, what is that you posted a picture of? I'm guessing a power source?

I've seen both of these before and they are helpful. Thanks!

its ok im an engineer ;) no frogs will be harmed in the making of this.

see where it says output:12V 1000mA
that means this will supply 12V up to 1Amp of (1000mA=1A) these fans will specify their mA and you want a supply that is 10% greater than that #. if you have two fans the supply needs to be 10% greater than the sum of the two fans.
Sadly, I'm not an engineer, nor do I have any understanding of electronics. A little elaboration would be great.

Also that is a 40 mm fan that is only 1.5 inches. I installed an 120 mm and after I wrapped with one layer of screen the airflow was drastically reduced, I even cut out small sections of the screen to try to help recover some air flow.



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Are you saying that one won't be enough for a 65g tank?
 

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ok mitch, very simple those black boxes are ac to dc converters. so obviously they go into a wall (ac) then the word "output" just means what it is going to convert to and the specifications it can provide. each converter is different and the label will tell you.

so the fan has a similar label it states draw. lets use the above pic
1amp supply

then say this fan (i dont know the CFM on it, but it had numbers i liked :) )
ADDA 40MM-CASE-FAN-2PIN 1.57" x 1.57" (40mm) ADDA Case Fan w/2-Pin Connector (Black), 40MMCASEFAN2PIN @ AntaresPro.com
it requires 12V which the power supply give, the fan needs .05A this means the power supply can give you enough amps for 18 (lets say 15 for safety).

the wiring is very simple, the wire sraight in two wire to two wire(+to +and - to-). if you need a control (potentiometer setup) look at the how to winner last month


honestly most the time they are .2A~
 

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I am just saying I am disappointed in the air flow I get after I covered my fan in screen and I have a 120mm in a 36x24x18 exoterra. I installed the fan in my tank (froglets are still in quarantine ) without screen wrapping and there was a nice breeze across my broms and all my condensation on the glass was gone. When I wrapped the fan, it was a lot less air flow and the condensation was back!


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I am just saying I am disappointed in the air flow I get after I covered my fan in screen and I have a 120mm in a 36x24x18 exoterra. I installed the fan in my tank (froglets are still in quarantine ) without screen wrapping and there was a nice breeze across my broms and all my condensation on the glass was gone. When I wrapped the fan, it was a lot less air flow and the condensation was back!


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Size doesn't matter. It's more about the CFM (cubic feet per minute air flow). There are big 120mm fans that don't move diddly squat and there are 40mm fans strong enough to almost lift themselves like a hovercraft if laid on their face. As a starting point, some of the cheap fans that only move 8 or 9 CFM are going to be more or less useless in a viv. My first fan barely moves the air. It was an eBay cheapy. I then made a batch of about 10 using this fan. 2410ML-04W-B40 - DC Axial Fans - NMB Technologies Corporation I still got a nice deal off of eBay for them. They move 21.5 CFM which I find to work quite nicely for my purposes. It is a 12 volt fan so uses a 12V convertor. Now I wanted simplicity in wiring so I chose to go direct wired to the transformer. It is still adjustable, however, because I got adjustable transformers. This is the type of transformer I got. 20W Digital Universal AC Adapter China (Mainland) Power Supplies

The transformer is adjustable from 3 to 12 volts. This allows me to turn it down to 9v or 7.5 volt if I want to turn it down to slow down the airflow. Now the amperage on my transformer is rated at 1.8-2 amps (2.2 max) We will look at the lower end for safety and say that it is only rated 1.8 amps.

The amperage draw on my fans is stated as .17 amps on the spec sheet, but the fan itself says .22 amps. For safety, I will be using the higher amperage and say that these are rated at .22 amps.

Remember back to Moty saying you need to allow an extra 10% amperage for safety? I like to just subtract that 10% from my transformer's amperage right now. 1.8 Amps - 10% = 1.62 usable amps.
Transformer 1.62 amps
Fans .22 amps each
1.62 divided by .22 =7.36 That means my choice of transformer will safely power 7 of my fans.
 

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Hello,
I'm starting the build for my 65g Peninsula :D. I have the tank and I'm currently building the stand, but other than that most of this is still in the planning stage. The main thing I am having trouble with is internal air circulation. I have a few questions pertaining to it...
1) How many/What size computer fans should I be using? Is there a rule of thumb?
2) How should I place them in the vivarium? Like Grimm's Peninsula setup? Or just mounted to the walls?
3) How do I power them? I've seen James's video but I'm still left a little confused. If someone could point me to a good thread about making a set up it would be greatly appreciated.

Any help/advice would be great. Thanks!
the number of fans needed will depend on their placement as well as the volume of air the fan is capable of moving.

the mounting style is up to you but mounting it in a way that will provide easy acess to the fan in case of failure will be important. this will of course be much easier if the fan is mounted outside of a duct system.

there are a few options for powering your fans.
yes you CAN use old computer power supplies or cell phone chargers but ONLY if the unit can power the fans safely. using an inappropriate power supply is a fire hazard.


Thanks for the advice Eric. Greatly appreciated. I plan on using this fan for air circulation. I was wondering how many I need, though. They are fairly expensive so I'd only like to purchase 1 or 2 if that will work.

Also, what can I use to power the fans? I will be plugging them in into an outlet and would like for them to be adjustable.

Thanks for any more help!
i do NOT suggest using that fan. it has a low RPM (revolutions per minute) and therefore doesnt move much air. (under 6 cubic feet per minute)

i suggest finding the fans i showed in my video. they are delta FFB0412SHN-R00. they operate @ 12V and push 24 cubic feet of air per minute. one fan will probably work fine, but id suggest 2 fans and i strongly recommend using a fan controller which will allow you to change the amount of air being moved to perfectly suit your viv. you will be hard pressed to find a single channel fan controller that can handle both fans (amperage) so you should look for 2, 3 or 4 channel controllers (even if you only use 2 of the channels, since 2 channel controllers are surprisingly difficult to locate)

If you cover in screen expect a substantial loss of air flow volume!
Sent from my iPad using Tapatalk
remember that the screen is rated a few ways, first the mesh. this value indicates how many wires there are in each direction per inch. of course the higher the mesh value, the smaller the openings will be. the next value is the diameter of the wires. meshes of the same values (like, as an example, 80x80) will have different size openings if the width of the wire is different. as the wire diameter increases the holes become smaller. which brings me to the final and most important value. open area. open area is the amount of unrestricted space for air to flow. it goes without saying that the more open space the less loss youll experience in terms of air flow. when you actually figure the open space of screens you might be surprised 50% or less would be a pretty common figure so your cutting the available space for air to flow, by a significant amount. putting one on both sides of the fan will compound this and its not surprising that you saw a huge decrease in the fans abilities. i suggest using screen wich is placed far enough from the fan that instead of protecting frogs fingers you need only to have mesh fine enough to seal the fan from froglets.

How is a cell charger used...? And how does it "hook up" with a computer fan??? I sure wouldn't want to electrocute any frogs...
the cable is cut, the wires are stripped and the leads are connected to the fan. i show how to do this properly in my video (using solder and heatshrink)

its ok im an engineer ;) no frogs will be harmed in the making of this.


see where it says output:12V 1000mA
that means this will supply 12V up to 1Amp of (1000mA=1A) these fans will specify their mA and you want a supply that is 10% greater than that #. if you have two fans the supply needs to be 10% greater than the sum of the two fans.
to figure the proper power supply requirements look at the fan's specifications.
voltage is important as this will determine how fast the fan spins. a 12V fan will operate usually from 3-12V and the amount of air moved decreases as the voltage is lowered (like by using a fan controller) do not supply more voltage than the fan is rated for since this can cause the fan to actually break apart and become very dangerous.
next and most importantly look at the amps that the fan draws. your power supply needs to produce a minimum of 10% more amps than the fan will draw. you can supply as many amps as you want (like to allow for more fans to be attached in the future) and the fan will be unaffected. its amperage rating of the fan is what it draws and it will draw that amount regardless of how much is supplied by the power source. (1A = 1000mA) the fans i suggest, for instance, draw .6A or 600mA. i would need to have a power supply capable of supplying 1320mA to draw 2 fans. thats 600mA each plus 60mA each for the 10% extra needed to ensure safety.

james
 

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Just wanted to throw my 2 cents in... when working with air flow and circulation my main goal is to get the leaves of the plants dry in 2-3 hours after spraying, and especially that they are dry before lights off (since the heat of the lights usually plays a part in their drying off as well so they may not dry off, and water sitting on leaves may end up getting cold and cause damage). Moving humid air can still dry off a plant pretty well without dropping humidity a huge amount!

I learned this the hard way over the years working with some more sensitive plants like orchids, ferns, and gesneriads... if the plant is fuzzy or hairy there will be issues if water sits on them for too long! Rotting out plants is a huge issue in many frog tanks so if you work out the air circulation the right way you'll be able to grow just about anything - and your frogs will be healthier for it too.
 

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I think everything has been mentioned except one thing.....Decibel rating! Meaning how annoying the fans will be. Im assuming this is a display tank, so Im sure you dont want it making noise all the time.

I had two cheap 40mm fans in my old tanks and they were terrible. In the peninsula I have two high quality 80mm fans that move 4 times the amount of air, and are rated 10db quieter then the 40mm fans. Try and find something rated at no more then 21-23dB and they should be almost silent using a glass top.

Also, I think for a 65 gallon tank you will want an overall airflow around 25-30cfm. I provide my 150 gallon tank with 60cfm 24/7, and its bang on perfect.
 

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grimm you beat me to it!!! the dBa on the fan was something that was important to me as well. the green ones i had pictured is an 11cfm at 26 dba. being these are for 55gal and under i have been happy with 11cfm on a timer that kicks on ever two hours. i do a 10 -15 min interval. if you use that cfm # you will do an air change on a 55 almost 4 times in a minute (this is with out a mesh, so the number is less)
im happy with a solid air change every two hours as any more than that will dry a tank out in utah with our dry relative humidity and gas fire furnaces in the winter
 
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