# Theory on how to create actual rain through condensation...



## Dendro Dave (Aug 2, 2005)

Ok I wanna run this theory by you guys and see what you think. Will it work? Suggestions on how to make it work? Are you aware of similar systems that have worked (show me)? Etc..etc..

Here is the basic idea...

First you'll need a viv that is capable of being nearly air tight while in "rain mode"... I figure a viv like this will have to have very little ventilation with a fan system making up for that and/or automated sliding ventilation covers or something, possibly through the use of servos or some other method that allows you to stop/close off the ventilation at will or through timers. I'd prefer an automated system on a timer, with manual activation by remote control being second most desirable. I'd like to avoid walking up to the viv and manually having to slide the ventilation covers into place.

Second a fogger, to saturate the air with water/humidity. A water feature might also be helpful to accelerate evaporation/condensation.

Third, clear or translucent dimpled glass/plastic panels similar to what covers some fluorescent lighting fixtures. Mount these either directly to the top glass or perhaps with a gap in between them and the top glass...I'm not sure which would be more effective. With a gap and possibly another panel with the dimples pointing up, you could drill a bunch of little holes between all the dimples and any water that condenses on the top of the panel should trickle down through the holes adding to the condensation collecting around the dimples on the bottom, as condensation gathers eventually gravity should take over and "rain drops" should form around the dimples then fall randomly(basically a sandwich of 2 panels with dimples facing out on both sides, if i wasn't clear) You might even want 1 layer with dimples mounted directly to the top and then a second sandwiched layer below that, then to get enough condensation and rain fall to created the effect....In theory.

I've seen rain chambers for research online using a similar principle, and I also saw where they managed to create clouds (though barely) by using lasers to atomize water in the air or something like that...but basically they just had a chamber with the air saturated with water and then fired lasers through it to create clouds which then produced small amounts of rain (I think). Here is an article about it... Making Clouds With Lasers - Science News

I wonder if a small laser like in a typical laser pointer(perhaps a really powerful laser pointer, capable of popping balloons or burning dark paper/plastic would be better suited for this) could be mounted in conjunction with a series of mirrors in the very topmost part of the viv, bouncing the laser around through the saturated air possibly creating a cloud but more likely just helping to spur condensation along so that the drops better form on the dimples and then fall.

One thing I imagine will need tweaking will be the amount of lighting to provide adequate but not to much light, while generating enough heat to cause condensation rapidly enough. Perhaps another light will need to be engaged for "rain mode" then can be shut off from timer or remote when exiting "rain mode". If the viv doesn't have a completely sealed/automated ventilation system, then some tweaking may be needed there also.

I'd like to try this method in a viv with a strobe and plasma glass lightning effects and an automated sound system that plays storm sounds on a loop. A simple rain bar type setup may be easiest, but I thought this would be a cool way to do it.

I also wondered about using some no see em mesh at the top and pumping the fog in from the top to see if it would kinda rest/be held there by the mesh looking like a clould(sorta)...That may even provide a suitable surface area for condensation, or spur condensation a long at the top to more rapidly/effectively create the rain effect. Not sure if it would let enough light through though.

Ok well those are the basic ideas so far...Thoughts? suggestions?


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## james67 (Jun 28, 2008)

is there any reason why someone would choose this over a rain effect driven by a pump? say in a week timer that comes on at nearly random times. its quite simple to create very convincing rain by using a tray with special holes that create the droplets. if designed correctly these systems can be pretty thin and can be easily hidden in the top of the tank.

james


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## Dendro Dave (Aug 2, 2005)

Ya a rain bar, or tray or some type of similar system is easier...but this has that "cool" factor...its ACTUAL rain  I just wanna know if it can be done also.

I was going to try it in the hex I'm doing now but I'm low on cash so I just extended the drip wall lines out, and then had them meet in the middle of the tank so they create a rain bar...then I'll poke holes in the lines so the water drips down the walls and also makes the rain effect where the line goes across the tank...should work, we'll see...haven't got far enough to poke the holes and run all the pumps and see if it all works like I think It will yet.I'm using aqualifter pumps so suction even with the holes poked shouldn't be a problem. 

Then there is a 3 tier waterfall attached to one drip wall that runs to the corner of the front pond and another line, that makes a small waterfall in the center wood making the shore, and then another line that will run water down some slate and river stones that make up the other corner of the front pond. So basically 3 waterfalls, 3 drip walls and rain bar and its all run off 2 tom's aqualifter pumps...but thats off topic and another post with pictures for another day. Back to Actual rain! 

Discuss...


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## Dancing frogs (Feb 20, 2004)

Put a peltier element in the top of your lid...will chill it down, which would make for much more condensation.
I agree though, that a pump driven system would accomplish "rain" much easier.


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## Dendro Dave (Aug 2, 2005)

I like the peltier idea And yes everyone I know there are way way easier ways to do a rain effect. Thats not the point, and I already know how to do those. I wanna see if i can create REAL rain in a viv, just for the fun/cool of it. 

Ok someone refresh me on my physics...I'm assuming that if you are suggesting mounting the peltier element in the top that means Its better to have the top cooler while the bottom is warmer right? So best for condensation is cold top, warm bottom right? So perhaps a heatpad kicking on during "rain mode" would aid in creating the effect?


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## Freeradical53 (Jan 25, 2008)

An interesting experiment. Rain naturally occurs when humid warm air reaches an area of colder air unable to hold the moisture. In order to create the effect inside a viv wouldn't you need extreme temperature levels over a height of many feet? If you use lasers, plasma or any of those other devices wouldn't it defeat the purpose of a natural environment??


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## JimO (May 14, 2010)

Dendro Dave said:


> I like the peltier idea And yes everyone I know there are way way easier ways to do a rain effect. Thats not the point, and I already know how to do those. I wanna see if i can create REAL rain in a viv, just for the fun/cool of it.
> 
> Ok someone refresh me on my physics...I'm assuming that if you are suggesting mounting the peltier element in the top that means Its better to have the top cooler while the bottom is warmer right? So best for condensation is cold top, warm bottom right? So perhaps a heatpad kicking on during "rain mode" would aid in creating the effect?


 It might be hard to maintain the temperature differential once it started to "rain" without stressing the plants/animals by having them experience temperature extremes. Remember, the "rain" will be a lot colder than room temperature and the heated area will be a warmer. It might be quite a shock for a cold-blooded animal to be sitting on some nice warm sphagnum moss and then have a drop of "ice water" hit him in the back. 

I think it could be done, but I fear it wouldn't be good for the inhabitants. It could also cause problems with the microfauna.


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## Dendro Dave (Aug 2, 2005)

"If you use lasers, plasma or any of those other devices wouldn't it defeat the purpose of a natural environment??"

I'm ok with lasers  ...especially if by some miracle I actually created a cloud. The plasma glass I mentioned is for a lightning effect (those panels like you see at novelty stores) ...I don't think I can get around some kind of "effect" there...Probably very very difficult if not impossible to create actual lightning in a viv and still maintain a stable environment for animals, plus if the lightning "struck"...that could be very bad for a frog, not to mention the plants  I guess I could build a viv around a Tesla coil...but I doubt that would be frog safe. But if anyone has an idea how to pull that off or some other form of natural lightning off I'd love to hear it!

"It might be hard to maintain the temperature differential once it started to "rain" without stressing the plants/animals by having them experience temperature extremes. Remember, the "rain" will be a lot colder than room temperature and the heated area will be a warmer. It might be quite a shock for a cold-blooded animal to be sitting on some nice warm sphagnum moss and then have a drop of "ice water" hit him in the back. 

I think it could be done, but I fear it wouldn't be good for the inhabitants. It could also cause problems with the microfauna."

I could be wrong but I'm not sure I'll need that huge of temp differential. I've seen condensation on the glass top of my normal tanks. That should be evidence that there is enough or close to enough of a temp differential naturally, I just didn't have a surface at the top that collected and allowed the water to fall as "rain". Basically I'm just looking to give whats almost happening in some of my vivs a little push and get it going enough to sustain at least a very light sprinkle...we don't need a monsoon here  I would also think that such small volumes of water would be rapidly reheated by the lights after condensing so that any "rain" that fell would not be extremely cold, but could be wrong there too. This water won't likely fall straight out of thin air (though that would be cool)...it will be gathering on a surface in liquid form and while it gathers enough weight for gravity to make it fall, it should warm up quite a bit.


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## MeiKVR6 (Sep 16, 2008)

Seriously, seriously overkill way to make rain - but I'd absolutely love to see it happen. Your vivarium would certainly be remembered! I'm no help on this one - but I vote yes for laser rain. 

Of course testing it on an empty viv for temp spikes, etc...


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## Ed (Sep 19, 2004)

Dendro Dave said:


> "I .Probably very very difficult if not impossible to create actual lightning in a viv and still maintain a stable environment for animals, plus if the lightning "struck"...that could be very bad for a frog, not to mention the plants  I guess I could build a viv around a Tesla coil...but I doubt that would be frog safe. But if anyone has an idea how to pull that off or some other form of natural lightning off I'd love to hear it!


If you are going to a real lightning strike and not a simple basic arc (which if I remember my electricity probably be accomplished with a spark coil from a large vehicle (or a large enough capacitor..) then you shouldn't forget the not inconsiderable shock from the superheating of the air and subsequent collapse back into the partial vacuum resulting from the counterstroke....... I think you would not only have to worry about the pressure of the air expansion and subsequent implosion turning the enclosure into some form of shrapnel.. Unless


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## RMB (Nov 26, 2009)

It rains every morning inside my fish shed. Being warm and humid in there, water condenses on the skylights, which despite being triple pane, are slightly cooler than the surrounding walls. It can make a fairly good puddle under each one, and it's annoying as heck when I'm standing there in my robe looking at my fish or frogs and a cold drop falls down the back of my neck. 

So, I don't know anything about the lasers but I think you have a fairly good chance with some kind of cooling element. How about doubling up the glass on top of the viv, with 1/4" in between, seal the sides of course, then recirculate water through that from a reservoir in a mini fridge.


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## Freeradical53 (Jan 25, 2008)

I like the idea of recirculating water on top of the viv. That way the warm moist air rising would most likely condense and fall like rain! However you would probably have to find some other lighting source.


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## poimandres (Mar 28, 2009)

This sounds like a very interesting experiment. As stated before, a bit overkill considering the ease of a pump and nozzle solution, but definitely a very cool solution. I remember a few years back some discussions regarding Green Tree Python husbandry (on another forum obviously) and someone mentioned the importance of dew point over humidity. I think this is in-line with what you are talking about as the dew point is the temperature at which a partial of humid air must be cooled to in order to achieve condensation. 

If I remember correctly, the goal was to maintain a hermetically sealed vivarium as close to dew point as possible so that any slight temperature drop would result in rain. 

Anyway, in case you haven't done so yet, do a google search for "dew point" and see what pops up. 

Good luck, and definately let us know how this pans out.


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## gluedl (Oct 8, 2008)

Hi,


real rain? As an engineer I am divided on the matter. 

Of course it would be very cool and all unique to see it rain " by itself" in a viv!

But then there is the technical aspect and ED:



> If you are going to a real lightning strike and not a simple basic arc (which if I remember my electricity probably be accomplished with a spark coil from a large vehicle (or a large enough capacitor..) then you shouldn't forget the not inconsiderable shock from the superheating of the air and subsequent collapse back into the partial vacuum resulting from the counterstroke....... I think you would not only have to worry about the pressure of the air expansion and subsequent implosion turning the enclosure into some form of shrapnel.. Unless


...is right depending on the voltage (some Terra-Volt needed in some cases) you will have to use for your lightning strike. These things are archieved in special glasses und nearly complete vacuum, to control/limit the arc (anyone remember the things we had as televisions before LCD and LEDsTvs surfaced? These were so heavy because of the vacuum tube for the electric arc and the electric field). So how do you want to control the arc in a viv? You will need an electric field, again of some TerraV to control the arc. There is a major risk here, shocking what's inside and outside (...you!). Ever been shocked by a Tazzer?

Then there is the condensation. Water condensates on surfaces that are COLDER then itself (see the tap and the mirrors when you take a hot bath), look for Hx diagramms, they show you how much humidity at what temps air can absorb and liberate. You will see that the volume contained in a viv will not be enough for rain so you will have to constantly feed the viv with warm and humid air. The temps of the air required here would kill frogs and plants. The cooling for live rain drops would be lethal again and not doable with a PELTIER element.

Last but not least is the energy amount needed for the laser, I don't know about the US, but the most powerful laserpointer you can buy here in EUROPE are 10mW and that is neither the right spectrum nor enough power to make clouds rain IMO. 

So still ultimately cool but also ultimately difficult and dangerous to achieve.

Have a nice day!

gluedl


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## bobzarry (Mar 2, 2005)

Sounds cool in theory but impractical. 
I remember my first viv. I wanted it as close to a rain forrest as I could get. So I used a humidifier and mister on a timer along with a recording of a thunderstorm fed into a color organ ( a device that uses sound to activate lights). I hooked up a set of bright lights to the color organ also on the same timer.
It was pretty cool for a while but soon grew boring.

This sounds much more elaborate and I would definitely like to see it in action if you make it happen.


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## Dendro Dave (Aug 2, 2005)

gluedl said:


> Hi,
> 
> 
> real rain? As an engineer I am divided on the matter.
> ...


Ya I'll probably be staying away from any real lightning inside the viv. I never really had any true hopes that would be doable. I think the plasma glass or a thin video screen mounted to the back outside the viv with a lightning loop playing is probably the best way to go.

On the lasers, I don't know whats legal here but there are several companies that will ship laser pointers in the 700mw-1watt range...wicked lasers makes a 1watt blue laser for 200 dollars that I believe is the most powerful pointer you can get now. It pretty much burns flesh within seconds, and blinds someone almost instantly, not to mention the radiation it emits can cause cancer and irreversible eye damage even when its being reflected from a nearby surface. Its insainly dangerous and i'm sure lots of morons or their moron buddies who don't realize how much more dangerous it is then a regular laser pointer will be doing permanent damage to themselves and house hold pets.

Are you sure about the peltier, and the temps and everything needed and it being lethal? As I've said before I already have condensation forming liquid water in some of my tanks, and that water would probably fall at least very slowly as "rain" if I just had a dimpled surface for it to collect on. It seems a few small measures to increase the effect I'm already getting naturally would be all I needed to make a light sprinkle. I''m not looking to make water fall from the air itself, that I can see requiring temps and conditions that may not be viv safe.

I've got a 10 gal vert that gets a fair amount of condensation and has an adjustable vent. I guess eventually when cash and motivation allow I'll just mount a little panel of clear dimpled plastic in there and see what happens then go from there. And depending on my results worry about automation and all that on a larger viv later.

But keep the ideas and comments coming...fun fun


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## Ed (Sep 19, 2004)

Hi Dave,

You could always try building the laser using plans similar to these Amazon.com: Electronic Gadgets for the Evil Genius : 28 Build-It-Yourself (0639785506966): Robert Iannini, Robert Iannini: Books 


If you are only looking for the flash effect, what about LEDs or even a strobe set for the time frame. 

Ed


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## Dendro Dave (Aug 2, 2005)

Ed said:


> Hi Dave,
> 
> You could always try building the laser using plans similar to these Amazon.com: Electronic Gadgets for the Evil Genius : 28 Build-It-Yourself (0639785506966): Robert Iannini, Robert Iannini: Books
> 
> ...


LoL, I've actually been meaning to check into those books. Not for this but just because I'm sure a lot of that stuff would be right up my alley.

Yes I've considered a strobe and found a few smaller models that should fit on top of a tank or the back without being to bulky and have an ac power source. I'd like to have both the strobe and luminglass plasma panels for the lightning effect. I was going to install them on the current hex I'm doing, but its going to friends. They are giving me 300 for it, but its already cost around 400-500 so the difference will be their wedding present. I don't wanna put anymore money upfront into that tank so if they decide they want the "storm viv" then they can give me the money and i'll retrofit it. I can pull parts of the background off so the luminglass will show through or install some little luminglass party lights that are battery powered and sound activated up in the corners...









The rest of the tank has been designed with this in mind. There is a rain bar, and its a glass top. So it should be easy to retro fit it into a storm viv.

My biggest hiccup is a simple system to play sound on a loop that can be activated by timers. I'd like to do it cheaply and I'm not sure what I can use that can be turned on by a timer and auto play without having to push a repeat button or some other button to start the process all over. i'd like to avoid using a pc, but I suppose its an option if I can find a simple to use program and connecting it all up would be easy. I thought of some type of ac powered mp3 player, but I'm not sure you can set one up so that it automatically plays that file when its turned on and off. I need to do more research on various controllers and effects hardware I guess. But thats the main thing holding me back now. I may start a seperate thread on that problem.


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## Ed (Sep 19, 2004)

Off topic.. but I used to own a copy of Build Your Own Laser, Phaser, Ion Ray Gun and Other Working Space Age Projects... until a few years ago.. 

Ed


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## gluedl (Oct 8, 2008)

Hi,



> Are you sure about the peltier, and the temps and everything needed and it being lethal? As I've said before I already have condensation forming liquid water in some of my tanks, and that water would probably fall at least very slowly as "rain" if I just had a dimpled surface for it to collect on. It seems a few small measures to increase the effect I'm already getting naturally would be all I needed to make a light sprinkle. I''m not looking to make water fall from the air itself, that I can see requiring temps and conditions that may not be viv safe.


To give you an idea about water concentration in air (taken from a Hx or Mollier chart) at different temps:


25°C at 70% hum: 10g water/kg air (1kg air = 0,83m3)

30°C at 70% hum: 25g water/kg air 

25°C at 100% hum: 27g

30°C at 100% hum: 47g

50°C at 100% hum: 82g

75°C at 100% hum: 240g

100°C at 100% hum: 490g

A 10gal will have a max air volume of 40l so you have to divide the above values by 30. At 30°C 100% hum you would have less then 2g of water in the air of your tank and I don't think this would be enough for real rain, but will work for a few drops/hour.

The cold energy needed here exceeds by far what a standard Pelletier element would put out, you would need a compressor based cooling system...


Hope that helps

gluedl


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## JimO (May 14, 2010)

You could probably get it to work, but the size of the "vivarium" might have to encompass and entire room in your house.


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## ChrisATX (Oct 7, 2008)




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## Hoodsquirrel (Jul 28, 2011)

Would this actually work? seems interesting..


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