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SinJin's Massive Two-Level Highland Cabinet.

Sep 2, 2013
Denver, Colorado, USA
This is essentially a modified/improved version of EdenCPs highland grow chamber. He has a VERY detailed tutorial regarding such: http://edencps.com/highland-nepenthes-chamber/

I'm using a 6 foot tall, 4 shelf Keter brand cabinet that I got from Lowes. Plastic was a priority as to minimize moisture concerns. The two shelves are just the standard ones that came with it, zip-tied in(for security but also repairability) and topped with egg crate.
The entire construction was done using minimal glues, pond foams, and hardware as I wanted this to be easily disassembled or repaired.

The dimensions were determined by the smallest radiator I could find (a 2000 civic radiator to be specific).

I'm using a Sanyo mini fridge to cool a reservoir of coolant, by reservoir I mean a trash can with rv antifreeze and water. I have also unfolded the freezer box(evaporator), and bent it down into the reservoir.

I then have a small pump recirculating the coolant in the reservoir, and a 730gph pump that pushes the coolant through 1" tubes coming out of the top of the fridge into the radiator. With a return going back into the fridge.

The circulating pump runs all the time to prevent ice buildup(i saw some at 25 degrees Fahrenheit), whereas the fridge itself is on a separate thermostat set to cooling at 30 degrees.

There is insulated ducting with a 6 inch inline fan that pulls the air from the top of the cabinet and through the radiator on the bottom shelf. The radiator itself has a shroud(that can't be seen) made from aluminum drip pans, silicone, and a lot of aluminum tape.

Using the water cooling system combined with an autopilot day/night thermostat(the large pump and 6" fan are attached to the thermostat), I am able to maintain a night time temperature of 59F(15C), with the reservoir maintaining a temp between 30-40F (-1 to 2C). This is cooling 14 cubic feet. I would also like to note that there are layers of blue foam insulation and reflective bubble wrap covering the entirety of the inside of the enclosure that helps keep temps in.

You may have noticed the pink hue in the radiator picture, that's due to the 300w LED's I have hanging IN the cabinet.

I counteract the heat put off by the LED's with a fresh air intake + hot air exhaust system, all powered by a 4" inline duct fan on the exhaust. The duct fan is set to the same timer as the LED's.
With this method, I can maintain intermediate temperatures with ZERO assistance from the cooler during the day, but I'm shooting for temperatures closer to 79F(30C) so it runs a couple times a day for about 3 minutes. The reservoir has no problem maintaining the 30F temps during the day.

I am also using a salt lamp on the same LED timer to activate the photocell on my thermostat, which allows it to select the correct temps.

With so much air movement and a severe lack of humidity here in Colorado, it's hard to keep the levels high. So I've counteracted that issue with 4 submersible humidifiers that are located in the final bottom water catch of the cabinet(plastic tub visible in pic 6). Two are set to run during the day only, with the other two running nearly all night and a tad during the day. I want to maintain as much vapor output as possible without burning out the humidifiers, as the methods I use to maintain my temperatures also decreases the humidity.

Things that weren't accounted for during planning
Watering the top shelf without ruining the Lights. This entire construction has free moving air and draining water in mind. So to account for drainage, I used the lid that came with the tupperware I'm using for the humidifiers as a roof/runoff guard. I've sealed all holes and concerning areas of the plastic guard with silicone as well.

Then comes hanging the lower lights, I had no idea how I would hang my lower lights. I tried a bunch of methods that required other hardware but I ended up doubling up the egg crate on the top shelf and threading the wire through, with a circular plastic brace to spread out the pressure from the weight.

This has been working lovely and I have seen no warping or any signs of stress on the shelf.

Now with these two shelves, I have a daytime temperature gradient between the top and the bottom. Some may find this an issue but I see it as a perfect opportunity to grow some more heat tolerant highlanders/intermediates. The top shelf stays about 5-10F warmer. With that said, I get even night time temps between the shelves.

Please feel free give feedback, suggestions, or to ask any questions!
Aug 4, 2008
Not much critique from me, that looks really well put together. You've got some heavy duty cooling there. Can even see a bit of ice on the container of antifreeze. It'll be a good home for highland neps for sure.