Ventilation, circulation and fan ideas

[Judy S]

more research...the magnets sound really strong...and potentially a problem. When you read about how they should not be near your computer...things of that sort...think I'd rather go for the hobby type...and the prospect of cracking the glass gives me the willies... have to look into this a little more...any more suggestions...welcomed....

[joneill809]

Hi Judy. Here are the magnets I have used - they come in a multi-size package. This was convenient for me because I could select different magnet sizes depending on the size of the fan:
http://www.amazon.com/gp/product/B0057V9H88

I have tried these magnets with 3/32" Lexan and glass without issue. Can't speak for heavier duty magnets, but so far I have not had a need for anything that strong (I'm using these for canopy mounts which are thinner glass). You may also have trouble with more powerful magnets when mounted near the fan motor - they may interfere with it.

[Judy S]

got my fans yesterday...now all I have to figure out is how the heck to take all those parts and make them work...I am absolutely unfamiliar with anything electronic...but I can make a heck of a martini.... Even though the fan comes with that miniature controller, it seems as though you connect some of the wires from the fan itself...to another controller...one to a tank. The only way to have sufficient light for an 18" Exo would be to have two hoods, and a fan in each??? Therefore, I probably will have one fan inside the vivarium with the protection you suggest. Since silicone does not reliably "stick" to plastic, what -- if any-- are your concerns with the magnets, etc., from dislodging?? ahhh...more research before committing...taking more time than it did to find my second husband...

[joneill809]

Even though the fan comes with that miniature controller, it seems as though you connect some of the wires from the fan itself...to another controller...one to a tank.

Yes, you need an external power supply, the "brick", that can either be a homemade unit where you splice the wires, or a kit that contains the socket that the connector on the fan will plug into. Some kits also support two fans with two sockets per kit, or if you get fancy you can buy a 3 wire splitter and drive two fans off the same power supply.

4 pin "molex" power supply ($15 @ amazon):


3/4 pin adapter (you should have something similar in your kit fan):


3 pin fan splitter ($0.60):

The only way to have sufficient light for an 18" Exo would be to have two hoods, and a fan in each??? Therefore, I probably will have one fan inside the vivarium with the protection you suggest.

I think "sufficient" is really up to the keeper. In my case, I probably went overboard. I use two hoods to help simulate different daylight conditions.
viewtopic.php?f=23&t=6815&start=40#p44165

I do place a single fan in each hood. I keep those two fans in the two hoods on the same power supply. For internal circulation fans I generally run a dedicated power supply since I tend to move them around and sometimes pull them from the viv altogether. It's really a personal preference. You may actually be able to drive 3 fans from a single supply if you pickup a few splitters. It's possible with as low as the rpm's are that one PS is enough.

Since silicone does not reliably "stick" to plastic, what -- if any-- are your concerns with the magnets, etc., from dislodging??

I use GE Silicone I. It seems to do a better job sticking to the plastics than Silicone II, plus Silicone I is supposed to be safer for the frogs. I have not had a problem with the fans releasing from the magnets [yet]. I've had them running for about 8 months. I do pull them down periodically and inspect the magnets, but i have yet to have an issue with the three fans I have been using. My azureus tend to inspect them regularly as well

ahhh...more research before committing...taking more time than it did to find my second husband...

Haha!

[joneill809]

This might be of more help - I snapped a series of photos of a new fan I am starting to work on. Here is the power supply ($8 from my local electronics store):
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The power supply has a 4 pin molex style power plug. You should have a converter similar to this that will convert from a 4 pin molex to a 3 pin:
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Plug the converter into the power supply, then connect the fan to the converter:
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And Phil - you are a bad influence. Your powers of suggestion convinced me to pick up two of these to experiment with:
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They are pretty light weight, and they move quite a bit of air. 1.5 oz total weight:
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I've selected a set of smaller magnets for this mount. I'll probably frog proof, water seal and glue on the magnets this weekend.

[Philsuma]

ahhh...the Squirrel ! Finally. Enjoy.

[Judy S]

My azureus tend to inspect them regularly as well take a picture of THAT!! Phil is trying to encourage the DD members to post videos...if you can, why not try to do that...people like me don't know the difference between Dbs, Molex, and FFs.... My ultimate aim is to install the fan you recommend on the Exo ...which will run probably 8 hrs. a day. Inside the viv, a perhaps 40 mm which can be hidden somehow in the plants would also run the same 8 hr. shift.....so from the fans, there would have to be a splitter...to a controller...to a timer, to the power source. This, in my mind, is probably what most Dart owners would like to get to for healthier frogs, and to expand the plant selection...to dry off sensitive leaves, and give the air circulation that orchids, and fuzzy leafed things demand... Now THAT requires some real -- to me-- explanation. And how does humidity affect the type of fan that would be inside a viv?? I even took the fan to a nearby computer store and they just could not help...I was surprised! Thanks for your patience...bet I'm not the only one who is picking your brains about this subject!!

[joneill809]

Phil is trying to encourage the DD members to post videos...if you can, why not try to do that...

Yeah, I'm not a big video person ... yet

Inside the viv, a perhaps 40 mm which can be hidden somehow in the plants

I'd probably go for something bigger. In my experience these smaller fans don't move a lot of air, and you need to run them at a relatively high speed (noisy) to obtain the same effect as larger fans. I'm about to post some ideas on hiding fans in plain sight that may be of interest.

so from the fans, there would have to be a splitter...to a controller...to a timer, to the power source.

I run fan w/ speed controller <-> splitter <-> power supply <-> timer but you could also do fan <-> splitter <-> external speed controller <-> power supply <-> timer.

And how does humidity affect the type of fan that would be inside a viv?? I even took the fan to a nearby computer store and they just could not help...I was surprised!

PC fans are pretty rugged. About the only thing I try to avoid is spraying them directly with my misters. They may briefly get a burst of high pressure water to knock some poop off, but other than that, they do quite well within the viv. I do try to dab silicone on the wire entry point and channel on the fan. I also silicone around the circular tape that protects the motor. My hope is that this improves the water resistance of the fan. So I suspect any $10 PC fan should hold up over the long term.

Thanks for your patience...bet I'm not the only one who is picking your brains about this subject!!

Glad to exchange ideas on the subject! Sorry for the long delay in posts - needed to turn my attention to the kids' toys for a while, now back to mine

[joneill809]

I picked up a pair of 60 mm blower style fans (aka squirrel fans) a few weeks ago.
http://www.amazon.com/gp/product/B004JPPTSK/


I tinkered around with one trying to frog-proof it with fiberglass screen but I managed to seize up the motor. (Apologies in advance - cell phone picture post - just didn't want to deal with the SLR for the build.) Though smaller and intended as a flush mounted solution for a minimal profile, it was really ugly:
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Second prototype
So I was indifferent about messing that prototype up. Tossed that in the parts bucket in the garage and moved on to candidate two with a different approach - use similar decorative materials that I used within the viv to camouflage and frog proof a magnetically suspended fan at the same time. I got to tinkering and didn't take a very good build sequence, but I took some shots of the final project. Basically I took a few pieces of small cork bark and siliconed it around the edges of the fan. I then filled in the gaps with extra silicone and stuck sphagnum moss in the wet silicone to cover it up. I'm using GE Silicone I, clear. Here's the shot of the blower fan prototype mark II:
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One piece of advice - keep your fan power supply handy while you are modding. Test the fan periodically to ensure you are not gumming anything up. It stinks getting a few hours into a project to find out you have destroyed or disabled your fan...

Test mounting
I have also been modifying a new 18x18 exoterra hood, replacing the stock screen with glass inserts and a 1" front vent. I used this canopy to test my fan mount:
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Holding power seemed good. I'll let this cure for another two days and then it should be ready for install. I am pleased with the blowers, cubic inch for cubic inch, they move much more air and are better suited to a magnetic canopy mount. I am tinkering with a mark III concept of a foam enclosure fitted to the fan, then camouflaged in a similar manner to this build. Using a foam housing approach would allow me to replace the fan...we'll see - don't have a need for another for quite some time

I'll snap some better photos when it's installed in the viv.

[Philsuma]

Very cool and innovative Jim.

[joneill809]

It's in! Here's a full tank shot from the galacts viv where this fan went. When you step back it's pretty tough to find the fan:
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A little closer:
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And a couple of close up views:
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It's working pretty well so far. I have placed the hood exhaust fans on timer now that the circulation fan is in. I'm sure this has stabilized the humidity fluctuations but I'll wait 24 hours before pulling the data logger.

[Judy S]

Jim...I "fixed up" my fan with a magnet...a neodynium one as you suggested...not strong enough for the glass that is between them to keep the fan in place. Are there stronger magnets, or is the size what makes it stronger??? The ones I bought are about the size of a nickle... Am ordering a 4 fan controller...and the various other things suggested...so am plodding along...

[joneill809]

Hi Judy. I think someone else suggested the Nd magnets - they are pretty powerful, more powerful than what I am using - I used a "variety" pack of magnets for my builds so I can test out a variety of magnet sizes. I use these:
http://www.amazon.com/gp/product/B0057V9H88


You could also try doubling up the magnets - one on each side. That assumes that there is some binding through the glass, but not enough to counter the weight of the fan. If you are having trouble getting anything to stick through the glass then that's another problem...

I'm using 3/32" glass on the canopy so it's pretty thin. If you are traversing thicker glass you may need bigger magnets. I have scrap pieces of glass that I use to test the magnets with some masking tape before gluing them in. What size glass are you using?

[joneill809]

It's in!

It's been a few days since I installed the new circulation fan. This fan seems to be more sensitive to the placement of the external magnets than the standard fans / vertical mounting method I had been using. It took a few attempts at moving around the external magnets to get the fan to run silent - if I placed the magnets too close to the fan blades they would vibrate. I did not encounter this issue when assembling; even though I had the power on during assembly, I did not include the exterior magnets during testing and placement of the interior magnets. Had I tested with the exterior magnets I probably would have went with a wider spread on the interior magnets.

However I solved the issue by using smaller external magnets (medium sized in the kit mentioned above) and I rotated them until the vibration reduced. Overall it's working well at keeping the glass clear and moving air. I'll pull some temp/humidity data tonight and see how it is doing coupled with the other changes to the canopy I have been making.

[joneill809]

Hi Judy. I think someone else suggested the Nd magnets - they are pretty powerful, more powerful than what I am using - I used a "variety" pack of magnets for my builds so I can test out a variety of magnet sizes. I use these:
http://www.amazon.com/gp/product/B0057V9H88

Hey Judy. I measured the magnets I am using. They are all approximately 1/8" thick, though the largest diameter is just under 1/4". Here's a photo of them, Large, Medium, Small, left to right:
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• 60 mm fan: mounted vertically are using interior magnets that are 1/2" in diameter (the descriptions on the packaging include the outer plastic shell). usually paired with a medium magnet for external mount.
  
• 120 mm fan: mounted with two of the largest magnets, 1.5" diameter x 1/4", one on each side. Paired with 2 large magnets for external mount. I think I could have gotten away with the mediums, but this was my first 120 mm mount so I wanted to be sure it held.
  
• 60 mm blower: mounted with two medium sized magnets internally, and two medium sized externally. I started with 2 large sized magnets externally but they interfered with the operation of the fan, destabilizing the blades leading to excess noise. The small magnets were not strong enough to hold this fan.

I leave the plastic shells on when I mount them. Hope this helps!

[Philsuma]

Jim, it's been a while. How are the fans working out ?

[joneill809]

Hey Phil! I've decommissioned all my internal fans after finding my strip vents along the front of the vivs combined with my custom hood exhausts were sufficient to draw air through the viv and keep condensation down. If you recall, I posted a build thread on vented low profile hoods here:
viewtopic.php?f=23&t=7615

And the original low profile hood here:
viewtopic.php?f=23&t=7420

The exhaust fans are situated in the front of the hoods, near the strip vents. Here's a shot of the two low profile hoods from the exo/zm build thread (you can see the hood exhausts up front under the fan guards):
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The strip vents are 1.5" wide solar screen siliconed in the front of the viv top. The rest of the top is glass. This is from the bakhuis build (frosted top):
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You can see the continuous strip vent on the right side of this image (this is a side shot, so the front door is on the right), and where the vent fan is positioned just behind it. The fan is a variable speed fan that I have adjusted based on vivarium data collected via in-viv data loggers. I'm able to fluctuate the RH between 80% peak daylight lighting and 95% overnight while maintaining consistent viv temperatures:
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My exhaust fans are tied to the "moonlight" timers, so that moves from active venting during the day to passive venting at night. I like this variation, and the plants seem to be doing well. The viv is not overly wet. So alas, much work went into internal fan designs, but they proved to be unnecessary after I figured out an active venting scheme that I liked.

[Philsuma]

Bumped ..