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A Very Cheap and Effective Highland Terrarium

My latest cooling design is on the next page.

So I recently received a terrarium from a friend. I have become interested in cost-effective setups, and a couple weeks ago I set up a 75 gallon lowland terrarium with only a sunny windowsill to heat/light it (it's exactly the same thing shown here without the cooling system). My plants love it. With my new terrarium, I decided to try my hand at highland nepenthes, which I have never really considered due to the extensive, power-sucking setups used by most growers. Here is my version, and my sole N. ventricosa (I'm starting with nothing fancy, so I can experiment without worrying about pricey plants) seems to like it.


Here's a picture of inside the terrarium. Gravel sits on the bottom, with water up to the tips of the rocks. Sunlight from the window evaporates the water and keeps it humid, about 75%. I don't want to resort to supplemental lighting, so I chose light-colored gravel to reflect light. I used some velcro to attach very reflective insulation to the back of the terrarium, as seen on the right. The pitchers on the ventricosa are showing some coloration, so I assume this is quite effective.

<a href="http://www.flickr.com/photos/84442298@N03/7748867848/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7108/7748867848_b053000a08_z.jpg" width="640" height="480" alt="Untitled"></a>


Now the most important part of a highland setup is the cooling system. I have read lots of different threads, and evaporative cooling seems to be the cheapest way to go. Although other kinds of setups are very effective, I didn't like the priciness of ones with water coolers pumping frigid liquid through radiators. Often times evaporative cooling systems involve fans blowing around mist from a humidifier, but I didn't want to spend the money on one, or pay for its electricity. I devised a simpler, albeit less-effective system. However, my ventricosa seems to like it.

Essentially, the cooling system is a cardboard box sitting on top of the terrarium with two holes for the exhaust ends of two computer fans. Plastic wrap surrounds the inside so the moisture doesn't destroy the box.

<a href="http://www.flickr.com/photos/84442298@N03/7748865212/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8428/7748865212_e7afd3ab09_z.jpg" width="640" height="480" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/84442298@N03/7748866404/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8443/7748866404_7be17d0206_z.jpg" width="640" height="480" alt="Untitled"></a>

The fans suck air over piece of thin cloth with long slits cut into it. I secured the cloth onto the box with thumbtacks around the perimeter.

<a href="http://www.flickr.com/photos/84442298@N03/7748864784/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8431/7748864784_9b234d567f_z.jpg" width="640" height="480" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/84442298@N03/7748867248/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7267/7748867248_2472327630_z.jpg" width="640" height="480" alt="Untitled"></a>


This cloth is kept evenly wet by having one end submerged in a long tray of water.

<a href="http://www.flickr.com/photos/84442298@N03/7748866848/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8284/7748866848_21cd6114bb_z.jpg" width="640" height="480" alt="Untitled"></a>


The basic concept is that water evaporates from the wet cloth when it passes through the slits. The evaporation chills the air, and it is blown inside to lower the temperatures within the terrarium. Remember to include an exhaust vent at the other end so it runs through the whole tank. Because it is evaporating water, it doesn't have much of an effect on the humidity at night.

<a href="http://www.flickr.com/photos/84442298@N03/7748865820/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8308/7748865820_b0bb72c028_z.jpg" width="640" height="480" alt="Untitled"></a>


I have the cooling system timed to go on for a few hours at night. Unfortunately, I haven't been able to get an accurate reading of the temperature of the cooled air. I doubt that it is any better than the more complex systems. It may not even be close! However, my ventricosa was putting out deformed leaves and refused to pitcher before I installed all of this. It now looks great, so I'm certain it works well enough.

The only problem I have run into is the wicking system. I have to place the cloth in the tray before the fans kick on, but if I do it too early, the water drips off the saturated fabric. This isn't really annoying, but it does waste some water. Also, if all the water in the tray is not used when the fans are on, it continues to wick and eventually drip. Either way, I have to fill the tray the next evening. Even if I were to have an upside-down bottle keeping the water level constant for a few nights, I can't stop the dripping until I pull the cloth out in the morning. I could avoid this by turning the fans on all night, from before I go to bed to after I wake up.

Anyway, I hope you like this system. It's appearing to work well. Any comments or questions are welcomed. I think if we all work together, we can make a very easy, cheap way to enjoy these marvelous plants. I will post updates as I refine the terrarium.
 
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Nice terrarium you got here! :D

Where did you get the fans? What is their power source?
 
as a wise person once told me, that tank is gunna be full before you know it! :) looks great dude. a fine job, rly dig the pebbles on the bottom
 
fix it so the cloth runs vertically across a vertical opening. put the water tray at the bottom. and to get good airflow across the cloth, place a diagonal baffle in the box so that the air has to pass through the same small area-no short circuit.
 
Everything looks great, dude! The only advice I can give is to go out and buy one of those cheap acurite hygrometers/thermometers to check what sort of highs and lows you're getting in there for both temperature and humidity. Other than that, I'm sure with a little extra tweaking to fix the dripping, you've created a very effective, simple system.
 
Nice terrarium you got here!

Where did you get the fans? What is their power source?

Thanks, I got them from Amazon. They are very powerful (110CFM each) and kind of noisy, but there is one with a smaller output if you don't want that. I have a transformer in case I ever want to slow them down. They use 110-120V; this way I can simply plug them into my timer.

as a wise person once told me, that tank is gunna be full before you know it! looks great dude. a fine job, rly dig the pebbles on the bottom

I hope it fills up soon! I need to start slow to test the system, but with some tweaking I think I could definitely get some harder highland nepenthes.

fix it so the cloth runs vertically across a vertical opening. put the water tray at the bottom. and to get good airflow across the cloth, place a diagonal baffle in the box so that the air has to pass through the same small area-no short circuit.

Really, really good idea! Do you think the wicking power of the cloth will be enough to get the water up to the top? Maybe I could have the tray on top and have it wick down, and then just have a collection tray at the bottom to catch the drips. I like the drawing, too.

Everything looks great, dude! The only advice I can give is to go out and buy one of those cheap acurite hygrometers/thermometers to check what sort of highs and lows you're getting in there for both temperature and humidity. Other than that, I'm sure with a little extra tweaking to fix the dripping, you've created a very effective, simple system.

Will do, I'd love to have some concrete data on this. I have an analog thermometer/hygrometer, but it isn't great at giving accurate readings. And it looks like pebes has fixed my final problem!
 
A Bit of Tweaking...

Here is The Cheap Highland Cooler 2.0! Basically, I took a bit bigger box, and made the open end vertical, not horizontal. I draped the cloth over the front. Above is a tray of water that will keep the cloth very moist. Below is a tray that will collect excess drips to be recycled for the next use. Wicking from the bottom would be ideal, but it simply won't work.

<a href="http://www.flickr.com/photos/84442298@N03/7755788432/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7114/7755788432_ee5c8fa44b_z.jpg" width="640" height="480" alt="Untitled"></a>

<a href="http://www.flickr.com/photos/84442298@N03/7755787578/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7275/7755787578_5be9064624_z.jpg" width="640" height="480" alt="Untitled"></a>

<a href="http://www.flickr.com/photos/84442298@N03/7755787992/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7246/7755787992_5c155f08db_z.jpg" width="640" height="480" alt="Untitled"></a>


Inside is a diagonal baffle made of cardboard. This doesn't change the speed of the air or the evaporative power, but it is a wonderful muffler for my noisy fans.

<a href="http://www.flickr.com/photos/84442298@N03/7755789584/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8297/7755789584_60dac29e36_z.jpg" width="640" height="480" alt="Untitled"></a>


Beyond this baffle are the fans. The only difference here is that the holes they blow air through are circular, it just aided in positioning.

<a href="http://www.flickr.com/photos/84442298@N03/7755789298/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8294/7755789298_5c2c2eeeb7_z.jpg" width="640" height="480" alt="Untitled"></a>


All in all, it has the same cooling power as the original, without the annoying dripping problem and noise. I would like to thank pebes for his ideas that greatly improved the setup and will allow it to go untouched for days. I can now sit back and enjoy my plants during the summer, with little cost. Any comments or questions are greatly welcomed. I will post updates if I further refine the system.
 
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Nice setup! Yeah, starting with easy-to-grow Nepenthes like ventricosa is a must. Even with all the grow tips out there you still need those building blocks :). What temps does it get outside at night? I would recommend having a fan duct suck the air from outside in at night if you get around 50*F temps at night. That will help a lot more if you decide to get true highland Nepenthes other then Ventricosa.
 
  • #10
Thanks! I think this contraption is only going to be used in the summer, as nighttime temperatures here hover around 65-70F for a couple months. The rest of the year outdoor temperatures can be anywhere from 50-15 degrees, so I plan on using ducts later on in the year. For the times I can't, though, I want to have a simple, easily installed cooler. Hopefully, this terrarium expands to hold many more interesting plants! I also have a tremendous 75 gallon lowland tank to fill as well, but that one is much easier to manage.
 
  • #11
looks great!!! good luck on the expansion of your collection.
 
  • #12
Thanks, I think my ventricosa will soon have lots of interesting company!
 
  • #13
A Little More Fiddling...

So I had some more time today and I decided to add to my cooler. I did some fiddling, and I think this may be the final design.

Here is the new and improved design. The most noticeable improvement is that I wrapped the box in insulation; this way the inside of the box will stay cooler and be more efficient. The diagonal baffle fell apart, and I decided I didn't need it. I made the cloth strips angle into the box so that they really cool the air inside the unit and elongate the time air blows past. I did this by moving the lower tray just inside the opening and securing the ends of the cloth with a few clean rocks. The top of the bottom tray has some spare insulation to keep the water from evaporating.

<a href="http://www.flickr.com/photos/84442298@N03/7784003456/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7255/7784003456_b802b58d3d_z.jpg" width="640" height="480" alt="Untitled"></a>

<a href="http://www.flickr.com/photos/84442298@N03/7784000774/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7260/7784000774_cf6658a2af_z.jpg" width="640" height="480" alt="Untitled"></a>

<a href="http://www.flickr.com/photos/84442298@N03/7784004612/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8428/7784004612_e0c4ef9824_z.jpg" width="640" height="480" alt="Untitled"></a>


The fans are still just inside.

<a href="http://www.flickr.com/photos/84442298@N03/7784003856/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8447/7784003856_ddcf2da0d1_z.jpg" width="640" height="480" alt="Untitled"></a>


I put a lid on the top tray to slow down evaporation from the reservoir.

<a href="http://www.flickr.com/photos/84442298@N03/7784001406/" title="Untitled by Sundrew, on Flickr"><img src="http://farm9.staticflickr.com/8299/7784001406_0f3cfd8c2a_z.jpg" width="640" height="480" alt="Untitled"></a>


Now, the most important improvement I made was widening the gap on the other side of the terrarium that air flows out of. This way, the terrarium inside isn't as pressurized and it allows the fans to work much better, allowing for more air flowing past the cloth strips. I just took some extra insulation and used tape as a hinge. It flies open when the cooler kicks on.

<a href="http://www.flickr.com/photos/84442298@N03/7784002236/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7279/7784002236_20c6503066_z.jpg" width="640" height="480" alt="Untitled"></a>

<a href="http://www.flickr.com/photos/84442298@N03/7784002860/" title="Untitled by Sundrew, on Flickr"><img src="http://farm8.staticflickr.com/7255/7784002860_621f139691_z.jpg" width="640" height="480" alt="Untitled"></a>


The design is similar, but it is these small tweaks that make it better and better. Every degree I can drop counts. Unfortunately, it has been very humid today, so my tests have shown minimal temperature changes. However, I'm confident in this design.

Of course, any comments, questions, or suggestions are greatly welcomed.
 
  • #14
WOW! great improvements! what temps are you dealing with?
 
  • #15
I'm going to have to get a digital thermometer so that I can measure the moving air. However, I could get a reading on the cloth itself, which hopefully should be close to the temperature of the air. It dropped the temperature from around 80F to near 70F. At night, when it's drier and cooler, I think the cloth could be down to 65. I think that means I'll stick with intermediates.
 
  • #16
Just a quick observation: for the cloth, use the cleanest water you have available. Because of my first version's dripping problem, I had begun using my usual rain water. Over time, this has gummed up the cloth with what I believe are microorganisms and just other gunk (it was pretty gross). This had severely hindered the wicking of the cloth. I washed it today and began using clean tap water, and it is wicking much, much better and will therefore cool my terrarium more effectively. Even tap water will leave some mineral residue, so be sure to rinse the cloth every few weeks for best results.
 
  • #17
Finally got some conclusive data. It's 28C (82.4F) and probably 55-60% humidity, and the air inside my cooler (just before it heads into the terrarium) is about 26C (77.8F).

The cloth itself is 21C (70F), so I need to find a better way for the air to be cooled by it.
 
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