# Vivarium Fan question



## Kudaria (Dec 24, 2013)

I'm planning on putting a fan into my vivarium to ensure a stead airflow over the plants. What types of fans do people most often use and why do you like them?

So far I'm wondering if some of the cabinet fan kits from coolerguy's would work in the vivarium or if I should try and find an aquarium fan because of the moisture. I would like to get a larger fan such as a 120 mm with a speed control, though perhaps a 80 mm would do just as well?

It's going into an Exo-Terra 18x18x24 enclosure.

Also how do people install them? As is with the grill and inset or do you put up screen mesh and then install the entirety of the fan on the top of the glass?


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## Judy S (Aug 29, 2010)

lots and lots of stuff in previous threads...look in Parts and Construction forums..most every question you may have will be covered...a 120 is probably too big for that size viv....


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## Kudaria (Dec 24, 2013)

Judy S said:


> lots and lots of stuff in previous threads...look in Parts and Construction forums..most every question you may have will be covered...a 120 is probably too big for that size viv....


Given the size of Parts and Construction, do you have any hints of what to search on? I'd love to see a few good build threads that include installing a fan into the viv top. As for the size of the fan I figured it was best to go bigger and turn down the speed of the fan rather than smaller and have it up to full speed?


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## Pumilo (Sep 4, 2010)

(said lightly) Are you building a vivarium or a wind tunnel?  Unless you are buying the cheapest, lowest CFM rated piece of (insert word here) ever made, that may be way too much fan for that size viv. You should be thinking about CFM rather than the overall size of the housing. Why would I want a 120mm monstrosity in my viv if I can do what I want with a 60mm? I'll link you to some fan info to get you started. 
http://www.dendroboard.com/forum/me...6581-pumilos-75-corner-viv-13.html#post692895
http://www.dendroboard.com/forum/pa...construction-using-spare-mistking-nozzle.html

Electrical info.
http://www.dendroboard.com/forum/pa...r-circulation-65g-peninsula-2.html#post677408


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## Pumilo (Sep 4, 2010)

Kudaria said:


> Given the size of Parts and Construction, do you have any hints of what to search on? I'd love to see a few good build threads that include installing a fan into the viv top. As for the size of the fan I figured it was best to go bigger and turn down the speed of the fan rather than smaller and have it up to full speed?


The Dendroboard search engine ignores small words like, "fan", so you could search for other words like, "circulation", or "airflow".
Some people choose to use Google to search Dendroboard.


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## Sammie (Oct 12, 2009)

120mm is really big, I use 40mm fans in my tanks and only run them at half speed.


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## Kudaria (Dec 24, 2013)

Pumilo said:


> (said lightly) Are you building a vivarium or a wind tunnel?  Unless you are buying the cheapest, lowest CFM rated piece of (insert word here) ever made, that may be way too much fan for that size viv. You should be thinking about CFM rather than the overall size of the housing. Why would I want a 120mm monstrosity in my viv if I can do what I want with a 60mm? I'll link you to some fan info to get you started.
> http://www.dendroboard.com/forum/me...6581-pumilos-75-corner-viv-13.html#post692895
> http://www.dendroboard.com/forum/pa...construction-using-spare-mistking-nozzle.html
> 
> ...


Evidently I was building a wind tunnel 

I've glanced over a few of those threads and have a few basic questions. The Exo-Terra has the bottom ventilation strip, I was assuming that I would simply want to mount the fan on top of the viv and either push or pull air from that vent. To dry the top of the leaves I was guessing that I would want to direct air into the terrarium from the top and let it exit from the bottom vent.

I see people are putting the fan in the vivarium from these threads, are you using solid glass tops or mostly glass tops with a narrow screen vent with this setup?


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## puremanb (Apr 10, 2009)

Just buy the cheapest fan you can get. You don't need an expensive water resistant fan. I've been running multiple 2 dollar 80mm fans, they get sprayed directly with water three times a day and still work 5 months in. I did take the sticker off the back pack a little grease onto the shaft and covered it with aluminum tape.


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## Pumilo (Sep 4, 2010)

Kudaria said:


> Evidently I was building a wind tunnel
> 
> I've glanced over a few of those threads and have a few basic questions. The Exo-Terra has the bottom ventilation strip, I was assuming that I would simply want to mount the fan on top of the viv and either push or pull air from that vent. To dry the top of the leaves I was guessing that I would want to direct air into the terrarium from the top and let it exit from the bottom vent.
> 
> I see people are putting the fan in the vivarium from these threads, are you using solid glass tops or mostly glass tops with a narrow screen vent with this setup?


I personally, do not care for combining 2 separate systems. I believe they should remain separate. I use *passive ventilation* on ALL of my vivs. Passive ventilation is simply a screen strip. Air is NOT forced in and out through passive ventilation.
SOME of my vivs also employ *internal air circulation*. Internal air circulation is the circulation of air within the vivarium. Internal air circulation does NOT force any air *exchange*. That means no internal air is forced outside of the viv, and no external air is forced into the viv.

Put a free standing fan in your living room and you are enjoying _internal air circulation_. Turn off the fan and open your windows and you are enjoying _passive ventilation_. Turn on the free standing fan, and open the windows, and you are enjoying internal air circulation and passive ventilation.
If you put the fan in the window, you are now utilizing a forced air exchange system. That means you are either forcing outside air into your home, or forcing inside air to go out. Either way is a forced exchange of air. That's fine in your living room, but in a vivarium, if you are not very careful, you could quickly lower the humidity levels lower than the viv inhabitants require.

I am of the opinion that every viv could enjoy benefits from passive ventilation and therefore I utilize passive ventilation in every viv. I am also of the opinion that internal air circulation can be beneficial, but is not necessarily required. I have used it in some builds and skipped it in others. My personal choice is NOT to employ any type of forced air exchange.


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## hydrophyte (Jun 5, 2009)

In my experience plants grow much better with internal air circulation than with passive circulation, but this is just what I have observed. A viv that is closed up pretty tight is also easier to maintain with consistent humidity levels and it will help to keep extra humidity out of your house. 

If you put a screen over the front and back of the fan it will slow the air flow considerably. This is also an important measure for protecting livestock from being harmed by the fan blades.


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## Kudaria (Dec 24, 2013)

Hmm all good points, thus the hole thru the glass, the elbow connection and the making of the little fan for the inside.

I guess I will be getting some experience with drilling holes in glass during this evolution of a basic vivarium.

I wouldn't bother with it except that I suspect airflow is rather like regular water changes in an aquarium, it prevents alot of problems that would otherwise crop up even with a good canister filter.


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## Pumilo (Sep 4, 2010)

Drilling holes in glass? Oh wow that sounds really hard, how are you going to figure that one out?  Oh wait.... http://www.dendroboard.com/forum/parts-construction/58594-how-drill-your-glass.html


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## Kudaria (Dec 24, 2013)

Pumilo said:


> Drilling holes in glass? Oh wow that sounds really hard, how are you going to figure that one out?  Oh wait.... http://www.dendroboard.com/forum/parts-construction/58594-how-drill-your-glass.html


LOL that I had already read about and had already looked on bulk reef supply for drill guides, plumbing and diamond drill bits. Though at this rate I may just get the entire set on Amazon.


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## Kudaria (Dec 24, 2013)

Oh I meant to ask, how many of those fans (40mm or 50mm) would you use in a 18x18x24 vivarium and where would you place them?


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## Pumilo (Sep 4, 2010)

Kudaria said:


> Oh I meant to ask, how many of those fans (40mm or 50mm) would you use in a 18x18x24 vivarium and where would you place them?


If you mean the fan that I linked in my 75 gallon build, one of them would be plenty. Where you mount is up to you. I usually mount mine at the top rear, so it can blow against the glass to quickly clear any foggy glass.


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## Judy S (Aug 29, 2010)

pumilo said:


> drilling holes in glass? Oh wow that sounds really hard, how are you going to figure that one out?  oh wait.... http://www.dendroboard.com/forum/parts-construction/58594-how-drill-your-glass.html


you're a trip....


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## konton (Nov 17, 2010)

Here was my build on internal circulation over the last week:






An then trying to mount it better to reduce vibration:






I hope it's useful. It's a 47mm round fan because . . . well I'm lazy.

Jae Le


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## Kudaria (Dec 24, 2013)

Heh I am a bit nervous about drilling holes in the 100 dollar vivarium...bit expensive if I crack the glass doing it.


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## Kudaria (Dec 24, 2013)

I wonder if quarter inch nylon screen will work even though it's not as stiff? It's used for some open topped aquariums when you have jumpers.


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## konton (Nov 17, 2010)

Kudaria said:


> Heh I am a bit nervous about drilling holes in the 100 dollar vivarium...bit expensive if I crack the glass doing it.


Its an Exo-Terra. There are spacers at the back for cables and tubes.Then you could mount the fan any way you want. 

As for mesh, it's cheap at the hardware store to buy a foot. I'd just do it.

Jae Le


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## gturmindright (Mar 15, 2006)

Where do you place/aim the fan in a tank utilizing passive ventilation and internal circulation? If you were using both would you get the lowest CFM fan possible?


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## hydrophyte (Jun 5, 2009)

gturmindright said:


> Where do you place/aim the fan in a tank utilizing passive ventilation and internal circulation? If you were using both would you get the lowest CFM fan possible?


Is there any reason to use both? I think this would just dry out your viv and make it too dry for frogs and plants. I don't think it makes any sense to use both for a dart frog enclosure.


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## gturmindright (Mar 15, 2006)

What if you are only using above and below door vents? What about the plants in the background and middle of tank?


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## Kudaria (Dec 24, 2013)

konton said:


> Here was my build on internal circulation over the last week:
> 
> Another terrarium fan build - YouTube
> 
> ...


Alright I really like the fan suggestion with the magnet that will allow me to move it around the tank.

I see that the round fan is a 47mm video card replacement fan and yes I can get it on ebay.

What are the other parts that need to be purchased for this? I'm more familiar with building computers and networks than doing anything with pvc piping.


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## 781frogger (Aug 26, 2014)

look into posi-taps for helping to connect the wires, i have not used these fan setups but i heard that will help along the way


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