Reeferator

Merlowe111

Well-Known Member
Hello everyone! Im about to start an ambitious Build for a grow box, I'd love to hear if anyone has any input on its feasibility or any modifications that could improve it! For a while I used to grow in a grow tent, it served its purpose but was painfully obvious what it was, and annoyingly loud with the exhaust fans. I had to make sure in-laws didnt see it, over all just very stressfull. I've seen online companies trying to sell these self contained grow units that cost thousands. I want to attempt to convert a working refrigerator into a sealed, climate controlled grow environment. Full automation isnt necessary, but I want to make sure temp, light timing, co2 ppm and humidity are controlled and monitored constantly. My plan is to change the thermostat to something like the stc-1000 controller. Use a humidifier/dehumidifier as necessary and control it with some type of humidistat. Co2 will be monitored and controlled by some type of controller as well, of course. My plan is to cut an opening in the top of the fridge, install some type of transparent barrier such as a double pane window glass and seal it all in. Keeping the lighting isolated from the grow space. I was going to use an led light like the mars hydro ts1000 and place it externally on top of the fridge in the hole I created so it can shine through the glass while passively cooling outside the control space. Hopefully the double pane glass reduces the heat transfer to a level the fridge can easily remove without significant reduction in light penetration. I plan on keeping the light in a fixed position against the glass and raising/lowering my grow platform to maintain optimal canopy height. I want to include a wifi enabled camera to monitor plant conditions remotely from my phone without opening the grow space unnecessarily venting my co2. I also plan on installing some type of cabinet lock to keep the reeferator safe from inadvertent intrusion. I hope to have this look like a typical anassuming fridge. And if anyone asks why its locked perhaps just play it off as a homebrew enthusiast with some type of light sensitive fermentation process going on that it cant be opened. In the future , if all things perform optimally, I hope to further the automation process using ardruinos and possibly actively monitor the ph and ppm of my hydroponic root environment as well.
So.....thoughts? Feasibility? I know it may seem like I'm overcomplicating it but I absolutely want stealth without the noise of air cooling and exhausting. I'm willing to take some extra steps to ensure that this thing is basically a fridge to anyone who passes it by.
 

calvin.m16

Well-Known Member
You're only going to be able to grow 1 single plant in the fridge. I'd recommend DWC if you're going to grow in a fridge or enclosed space. Less chance of mildew/mold and bugs. Vent cool air from the lower portion and exhaust out of the top portion of the fridge. You could also lock the fridge which is kinda cool. Good luck! :D
 

MrFlatbush

Well-Known Member
I run something similar but slightly less ambitious. I too made the light external which greatly helps keep temps down. However, due to the greenhouse effect you will still get a small temp increase inside the fridge. The small temp increase is easily handled with your ventilation. The other huge benefit is that this will also greatly simplify your odor control. Your exhaust fan will not have to both cool your box in addition to scrubbing the air. It will mostly just have to scrub since you have already eliminated most of the heat. Feel free to message me if you want to know more. Good luck with your build. I had just as much fun engineering mine as I do with growing.
 

Merlowe111

Well-Known Member
Keep in mind that glass blocks parts of lights. I don't know how this will work out with the led.
I was concerned about this as well, I found very little information about double pane glass and its effects on light penetration. All info focused on heat transfer. And unfortunately i dont have the equipment for measuring light. I did see that double pane glass is used in some greenhouses, so it seems feasible at least. If anything, I may have to upsize my light or add auxiliary lighting to compensate for any negative effects from the glass. If the temp transfer isnt terrible I might get away with just single pane. Thanks for the input!
 

Merlowe111

Well-Known Member
You're only going to be able to grow 1 single plant in the fridge. I'd recommend DWC if you're going to grow in a fridge or enclosed space. Less chance of mildew/mold and bugs. Vent cool air from the lower portion and exhaust out of the top portion of the fridge. You could also lock the fridge which is kinda cool. Good luck! :D
Thanks for the insight! I have very little experience with hydroponic growing so this is very useful to me. I'm typically growing in soil, but with this project, some form of hydroponic growing just seems more prudent. It will be a learning curve for me.
 

Merlowe111

Well-Known Member
I run something similar but slightly less ambitious. I too made the light external which greatly helps keep temps down. However, due to the greenhouse effect you will still get a small temp increase inside the fridge. The small temp increase is easily handled with your ventilation. The other huge benefit is that this will also greatly simplify your odor control. Your exhaust fan will not have to both cool your box in addition to scrubbing the air. It will mostly just have to scrub since you have already eliminated most of the heat. Feel free to message me if you want to know more. Good luck with your build. I had just as much fun engineering mine as I do with growing.
This is great input, thanks! Just to clarify though, did your system still exchange air from outside the box? My plan is to have zero air exchange unless the door is opened. And run the system completely sealed from outside air using co2 supplementation. And rely on the refrigeration cycle to remove any sensible heat outside of my preferred settings. Ideally I dont want to have an air intake or exhaust. But I do plan on having some type of charcoal scrubbing within the box for odor control.
 

GrnLeavz

Member
I was concerned about this as well, I found very little information about double pane glass and its effects on light penetration. All info focused on heat transfer. And unfortunately i dont have the equipment for measuring light. I did see that double pane glass is used in some greenhouses, so it seems feasible at least. If anything, I may have to upsize my light or add auxiliary lighting to compensate for any negative effects from the glass. If the temp transfer isnt terrible I might get away with just single pane. Thanks for the input!
Well there are 3 main factors to determine transparancy and isolation of glass. There is a "U-value" a "G-value" and the light transmittance.

The first one is used for heat transmission. It gives the watts per minute per m2 that passes trough the glass. The lower the more the glass isolates.

The second one (U) is used for how much of the solar rays get trough the glass. This might also apply with growlights I'm not sure i guess it matters a bit. This goes from 0 to 1. The higher the more of the sun gets trough.

Then we have light transmittance. It displays the light transmittance offcourse :p you want this as high as possible.

I found the following on a manufactures website:

Single glass: U: 5,37 G: 0,81 LT: 89%
Double glass: U: 3,20 G: 0,70 LT: 80%
Triple glass: U: 0,80 G: 0,50 LT: 0,64

P.S: I speak Dutch so i hope you can understand everything :p
 

Merlowe111

Well-Known Member
Well there are 3 main factors to determine transparancy and isolation of glass. There is a "U-value" a "G-value" and the light transmittance.

The first one is used for heat transmission. It gives the watts per minute per m2 that passes trough the glass. The lower the more the glass isolates.

The second one (U) is used for how much of the solar rays get trough the glass. This might also apply with growlights I'm not sure i guess it matters a bit. This goes from 0 to 1. The higher the more of the sun gets trough.

Then we have light transmittance. It displays the light transmittance offcourse :p you want this as high as possible.

I found the following on a manufactures website:

Single glass: U: 5,37 G: 0,81 LT: 89%
Double glass: U: 3,20 G: 0,70 LT: 80%
Triple glass: U: 0,80 G: 0,50 LT: 0,64

P.S: I speak Dutch so i hope you can understand everything :p
This information is golden! Thank you! With this I will try single glass first and if I can control heat, I'll stay with that.
 

MrFlatbush

Well-Known Member
This is great input, thanks! Just to clarify though, did your system still exchange air from outside the box? My plan is to have zero air exchange unless the door is opened. And run the system completely sealed from outside air using co2 supplementation. And rely on the refrigeration cycle to remove any sensible heat outside of my preferred settings. Ideally I dont want to have an air intake or exhaust. But I do plan on having some type of charcoal scrubbing within the box for odor control.
I am not sealed. My mini fridge inhales and exhales. I don't have any experience with sealed, sorry.

Keep in mind that the fridge motor will likely be just strong enough to keep cold things cold. Once you add your circ fans, Humid/de, water pumps, and air pumps if going hydro, web cams, raspberry pi's, all of those electronics will contribute heat that will need to be dealt with in some way if you are truly sealed. I would find a way to make all of those components external, like your planned light, if you can.
 

Merlowe111

Well-Known Member
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Very roughed in, holding temp for one hour so far. That's without being properly sealed and no glass. All of which I believe will make this build even more efficient.
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Merlowe111

Well-Known Member
Creative AF, my brother. :bigjoint:
I appreciate the compliment! I hope others see this project and can use it to make their own versions and build upon it. This unit makes growing possible regardless of climate or living space. Completely silent, stealthy and unassuming. With excellent insulation it can cool itself with no problems even in my shed that reaches afternoon temps well over 100f and the warmth of the light perfectly protects against temps near the low 30s without the need for auxiliary heating. Its not the prettiest, but I believe it definitely proves that it can be done in a DIY fashion. No need to spend thousand on automated grow boxes. It may be a welcome relief for those like me, who constantly struggle with temperature related issues that couldn't be reasonably solved any other way.
 

Axion42

Well-Known Member
Here is his revised link, I've been following, any new updates? @Merlowe111
 

Merlowe111

Well-Known Member
Here is his revised link, I've been following, any new updates? @Merlowe111
Thanks! I was considering just letting this thread die, but wanted to at least put it out there that it worked. Fridge is working perfectly. But I have a large learning curve with the hydroponic aspect of it and am currently battling an unknown problem plaguing my plants.. i made some adjustments so with time hopefully all recovers. But I still haven't definitively diagnosed and solved the problem so I can ensure it doesn't happen again. Which is bothering me. It could just be on account of my own ignorance, there are many "firsts" I'm dealing with on this. First time using co2, first time using LED. First time in hydroponics. Lots of rookie mistakes on my part, I'd imagine. I just dont want my failures on the growing side of things to give the impression that the reeferator doesnt function as it should. I can fabricate all kinds of things, but I'm still a shitty grower. Lol20200123_151140.jpg20200123_151150.jpg20200123_114531.jpg
 
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