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Freezer grow

woods brother

New Member
Has anyone ever swapped out the thermostat on a freezer or refrigerator to set it at 72 degrees for a grow cabinet? I have a vertical deep freeze that I ordered a digital refer. thermostat for, to replace the factory unit to maintain a proper temperature grow environment. With all the work I got done waiting for this dang thermostat to arrive I sure hope it works!

I know freezers are very well insulated and the heat produced by the lights/ballasts will get trapped and... Bad JuJu! That being said I emptied and defrosted my vertical type deep freezer, drilled a hole in the bottom for power cords, and cut a hole in the backside, top for an exhaust vent, installed a pair of quiet fans to pull in fresh air, threw in a few t8 48" lights plugged it all in and 24 hours later the freezer was a cool 50 degrees. Yes it ran non stop, yes that would be expensive, but it was just a test to see if it was feasible. So off I went to the orange Depot...

Lighting provided by, 8 42 watt, Color Temperature (K) : 2700 °F CFLs, 2600 lumens each. and 8 27 watt, Color Temperature (K) : 5000 °F CFLs, 1750 lumens each. I need the t8s above mentioned for another project and with a ton of CFLs laying around I figured I would give it a shot. 34,800 lumens in a 34 cubic foot box, I can remove bulbs if too much. :hmmmm:What do y'all think?

Fresh air will be brought in from under my barn (cooler air in the Summer) and directly into the freezer by 4 inch PVC (topped with a HEPA shop-vac filter for bugs and particulates). I ditched the two small fans for a single 4 inch unit that will change the air roughly twice an hour. It exhausts out the back in the top of the freezer and then turns a sharp 90 and is vented out under the barn for stench control.

CO2 will be produced by the door, well kinda. I am going to make use of the door shelves by filling some trays I made with a slurry of activated yeast and feeding it a few tablespoons of corn sugar simple syrup each day I water. It is cheap easy and when it gets full you dump it out and start over.

Air movement by desk type oscillating fan epoxied to the back wall (got aggravated stripping screws and well it is permanently mounted).

Plants, well I can't decide I have a bunch of Pineapple Express and Sour Cream clones ready to go. In my big grow room I usually vegetate to about 12-14 inches then flower out, but I am thinking about planting one big Power Skunk and letting it get BIG before I kick it to flower. Even thought about two shelves of Auto-flowering dwarfs, I dunno? Give me your opinion!

All this may be for not if the controller doesn't work, but hey this kinda stuff is what it is all about. I have more fun building and growing than anything else. Y'all are awesome, lots of love and please fire at will on my box, I need the input!
 

woods brother

New Member
O.k. here we go the refrigerator was a craigslist freebie. It works great and only took a little cleaning to make good as new (liberal use of bleach).

Let the modifications begin! The biggest factor in these types of enclosures is heat dissipation, not because everybody has that issue but because this thing is basically a giant thermos and will get 100 degrees with one 100w bulb. So I went to my local beer and wine making shop and picked up this thermostat for making kegerators and controlling brewing environments. It will set you back $70 for the analog version and $100 for the digital.
 

woods brother

New Member
This refrigerator was made to have a ice maker so the hole where the water inlet goes was a great place to bring in the power cord and thermostat sensor wire and still maintain a sealed environment.

I needed to equalize the temperature in both compartments and pull the warm air out of the refrigerated section so I drilled four inch and three quarter holes right next to the intake for the air cooler. Also seen is the wire loop for hanging the lights in the lower compartment.
 

woods brother

New Member
This is where the brains of system are stored. Outlet for lights, timer, fan, CO2 controller ect. Will also serve as a great place to start seeds and begin vegetative growth. Note the adjustable hight shelf, I am thinking two high output two foot fluorescents for the top of this compartment.

A few things to mention here. The light is my DIY 16,000 lumen 2700k flowering lamp ($50). Set the freezer and refrigerator to there coldest settings for even cooling. The fan in the door is a basic 8 inch commercial grade fan that I leave on 24/7.
 

woods brother

New Member
The original glass shelves have been re-purposed to allow the plants to be lowered as they grow. The light hanging is a 90w blue only for vegetative growth. Threw a rough looking poinsettia in there for a few hours this morning and she perked right up, amazing little light!


I set the thermostat to 70 degrees and in the first 24 hours the highest recorded temperature was 77 degrees and the lowest was 70. In my garage it has ranged from 23 to 55 degrees. I have added some tape to the freezer air exhaust to force more cold air into the refrigerator compartment and since doing that my temperature hasn't gone out side or 70 to 72 degrees. All and all I have in it is about $200! This includes my CO2 system to keep it up to about 2000ppm. Oh and for humidity control I have a stoking filled with silica I hang in the back.

:slide:Odorless, cheap, totally stealth and I built it myself.:slide:
 

woods brother

New Member
Catastrophic failure!

Compressor failed last night, temperature spiked to 142 degress and well I lost a beautiful Pineapple express :rip: and Super skunk/Jack Herer hybrid :rip:, along with my sweet mint :rip: and the wife's brussel sprouts :rip:. I am just crushed the plants were about 16 inches tall and I was gonna flower once they got settled into their new 3 gallon smart pots. Oh well I have two more refrigerators I was going to build for some friends so after church :amen: I will be moving all from one to another and starting again.

Am just crushed!
 

woods brother

New Member
Rebirth!

Sorry for the week lag update. I got to tearing into the box and be damned if it wasn't my CO2 system that caused the temperature spike! I had a lantern burning to produce CO2 until my fermentation tanks got rolling. The fan that was pulling the hot air out of the box that was "pooling" the CO2 quit and the heat built up... heat source in a cooler! I hate to say it but I took a STUPID risk and it cost me dearly. UPDATE, I grabbed 8 bag seeds from some good stuff that popped off in a buddies grow room and have and unknown pollen donor to a Sour Cream momma. All germinated and are doing great under the LED. I build a new light box based off a Clown Grow. Eight sockets in a 22"x16" box, made it from some 1x4's, sheet of plywood, and a sheet of acrylic. Best of all... I cut a 7.25"x7.5 hole in the center and installed a 50 cfm bathroom fan. I will post some pictures when I finish my odor control filter and or fresh air circulation.
 
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