Fridge Build

Hey ICMAG, Looks like theres a new place for post building and projects. Kudos Palindrome for getting this room started.

Fridge build: The idea is to have the grow (usually no more than one or two plants in some buckets) outside of the house - for discretion. An old fridge was ideal, its well insulated so keeping temps stable for when its out in the shed.

Dimentions: 40x60X106 cm (0.28m2) (9.8 cubic feet)
Climate: cold - warm and humid (ireland)
Power: 150-200 watts (LED)
Growing Medium: Soil
Air flow: undecided



Heating System -
the heating system is there to keep temperature stable and to stop things getting too cold when the lights are off at night. Its just some industrial heating cable for piping (about 160watts of heating).
1. Temperature probe for heating system
2. Heating wire

Intake and exhaust -
3a&b. 2 80mm fans. these are on a temperature controller and only turn on when things get over 24C (75F). im hoping passive flow should be enough. Though i should give the ventilation sticky a proper read throughat some point. Really not ideal if they turn on and blow in some frezing cold air. This needs the most work.

Lighting -
4a&b. Lighting 100watts (2x50) cob leds, these are cheap driverless lights (220v). BigClive on youtube did a video on them.

Aggitation -
5. 4x 80mm fans ment to make some wind havent tried it yet and the mount is awful - to deal with later.

Medium -
6. 20L veg tray from the frige. Its too big to fit on the slide system (7.), so may downsize to a 10L tray instead.

Theres a tomato in there at the minute, just to see if it will survie, it was in a bad state going in but its not getting better haha - not a good sign.
Next things to do is add 100w of side lighting, improve the vents, get a drainage system for the soil and maybe blumats. The idea is to have it be able to grow without much intervention.
Also the photo is poorly lit because the driverless LEDs have a strobing effect (to the camera) since theyre straight on the mains. ill get some better shots at some point.
Happy growing all.

Looking good, I think you might need more air exchange or to add Co2.

Could be the reason, your tomatoe isn't thriving.
If possible, try and set your exhaust to run with the lights.
So your plants will get fresh Co2, when they need it.

That been said, it's looking like a nice and stealth unit.

Figured it was a bit big to post in the micro section.

Thanks for the tip with CO2, ill play around with intake and temps then.
Happy growing!

Nup said:

Figured it was a bit big to post in the micro section.

Thanks for the tip with CO2, ill play around with intake and temps then.
Happy growing!

Click to expand...

It's cool, this forum is not about size but DIY grow rooms.

Keep us updatet, on your upgrades and good luck on your project.

Glad to hear that any diy build is welcome!

So, onto some updates:


The tomato is doing OK, no real growth or improvement yet, but its a bit greener.



I had put in a fancy "smart" thermometer/hygrometer into the fridge two weeks ago. It wasnt bought for this intention, but it has given some very useful information about whats going on! Cant imagine going into this as blind as i'd once thought.





The lighst are on a 18/6 cycle, with lights on during the night to help with the cold. Outside temps recently have been bellow freezing (-5C (23F)) and up to 10C (50F) during the day. The graph pictured is during some of the coldest days.

Its interesting to see that the spikes that are happening (24-19C (75-66F)) are when the lights are off (only the heating wire heating) are when the fridge is at its hottest. I dont know how poorly the plant will accept those temperature swings, as its quite rapid over the course of a half hour. I dont think there is a way to improve the sensitivity of the copper probe that came with the heating wire controller.. Myabe make a heatsink for it?
Usually the temp drops to 17C (64F) during the nights (lights on). So 15C (59F) is a good worse-case.



The sensor also told me that RH varied around 30-50, averaging 40. Which is very low (ambient is pretty consistantly 85). This may be why the plant is suffering(?), espeically if its also lacking CO2. Though the bright side is that theres no real need for a dehumidifier, hah!.



All in all; its working. The plant can live in the fridge at outdoor temps.

This week only the led cooling fans have been lowered, maybe less hot air blown down will help it pick up.



Also saw a video looking the perfomance of the driverless COB led's. Not great it seems... but proper lights are very expensive.



Lots of text for ye there! Its easier to "think aloud" at least thats the excuse, lol. Happy growing.

Love fridge builds!

Guessing you will be warming up after winter and all should work well at that point?

Anyway, I have a suggestion for a device that can be built cheaply (unlike commercial models for houses that cost 1000's), that might be able to help you out. And fun to make, as well as be able to mounted on the fridge inside or out.

A DIY heat recovery ventilator, that will not only save around 70-80% of the heat you pump out, but also can pre warm the freezing incoming air, and adding your c02 back to the fridge while ventilating it at the same time. During lights off you could use it in conjunction with a small screw in ceramic heater, etc..

https://www.instructables.com/id/Air-heat-exchanger-Made-from-soda-cans-and-pvc-pip/


https://www.youtube.com/watch?time_continue=130&v=baHbOtkbgwY


Not many people utilizing a HRV with there grows, because of the cost for pre built units i'm sure, but man can they be useful!

Hey Drop That Sound, Thanks for the comment.


That heat recovery system is terrific, ideal for the situaltion at hand. It'll no doubt help with temp changes and solve the CO2 issues, as you've said.



I'll post some design ideas and the likes as it comes along. Cheers.

Welcome man, I think it would help too.

I've planned on making one, but instead of one long pipe, I was gonna do a whole wall full of the pipes (stacked next to each other) with a manifold on the top and bottom, and design it so I can replace the soda can cores a few times a year. I only really want it for winter time, for my unsealed veg chamber, to save on heat.

Considering your in a fridge you could considerably scale the project down, using just a few cans and 2 small fans. Or using smaller cans like redbull energy drink sized ones, with a smaller diameter pipe.

The key to remember is to have the same amount of air flow through the cans, as around the cans and in the pipe. Try to calculate the area of the gap between the pipe and cans, and that's how much you need to drill out to go through the cans.

There are other plans to make cross flow cores for DIY HRVs, but the pop can idea is awesome! It can work better than a $5000 commercial unit, but no one wants a bunch of pop cans in a long pipe and rather spend money on a small core I guess

Hey again all, slow few weeks lately.

DropThatSound: That manifold idea would look great, did you ever have a go at making it? Had a breif look at your posts, some mad stuff in there! The air layering was a surpise - I had no idea that was an applied technique.

Cheers for the tip with regards to airflow and area, makes sense.

An update; Its frustrating living away from the grow, only get to work on things the odd weekend.

I have a core made up of red bull cans, have to be out buying some tubing one of these days.

Lastweek i changed the airflow setup. Now its on for five minutes every 40 mins. Results are nice, the temperature line is flatter, so to speak. So that works. I think less airlfow more frequently 30 seconds ever 10 mins or so. But the current simple timer cant do less than five mins.

Anyway, Graph time.
Temperature:


RH:



Also the tomato is getting worse, dont have the heart to show a picture hha.

Happy growing.

I just been saving the taller arizona ice tea cans up, but for sure plan to do the manifold idea someday soon, but im backed up with like 5 unfinished projects lately, and winter is about over and i had to shut down everything for awhile. I really cant wait to do it, starting with my work are/veg room which i wont be running c02.

The cool part about doing it that way instead of one long pipe, is I can fit like 100 ft worth of pipes against a wall, while only taking up 4 inches of space. It will gaurantee me super high effeciency at least 90% of the heat being retained. And 4 inch sewer pipe is cheap, as are the cans if i can find someone that drinks lots of beer or other sugary beverages and save the cans lol.

Also can put a condensation pump on the bottom of the lower manifold, or let it drip from the intake just outside the wall through the lower port.

I also planned to change the size of the holes in the core (getting bigger and bigger on the pipes on the sides) so that the air flow is more equal going through them all, considering the manifold intake and exhaust ports will be in the center of the manifold. In other words, i dont want most the air going through the middle pipes only by finding the path of least resistance, so i will make the center ones a little more resistent with smaller holes.

Ive came up with a plan (not on paper yet) to actually design the diy HRV can idea right into the walls of the house im building, instead of insulation. 2 whole walls on each end of the house with 4 inch pipes filling all the spaces between the 2x6 studs, from one side of the wall to the other. I was thinking of having it so one wall is the intake and the other one on the other end of the house is the opposite and always exhausting. That way the house is always having fresh air blowing through and also retaining upwards of 90% of the heat, or even air conditioning for that matter!

I probably wouldnt use cans in that case but instead use aluminum semi rigid dryer vent or something. Maybe wrap aluminum flashing that comes in a roll around a pvc pipe to save money and make my own cores.

One issue with the glued up cans is you cant really clean the cores if they start growing mold, but for a small setup like yours it would be cheap to just make new ones every few months, and design it so you can swap them in easily. There are products you can spray to minimize mold growth.

I think in your fridge one long pipe from top to bottom with rebull cans would be enough, or if up on the ceiling maybe 2-3 smaller ones with a manifold.

Ive seen some people use the fridge as the ac itself, but im sure the compressor would crap out in no time. I always thought it would be cool to set a small window AC or 30 pint dehumidifier on top and bend the condesor coil down in, or even solder up a better system to the existing cores already in the fridge and refill with refrigerent. Wish I had an HVAC buddy that could help on some projects!

Theres a guy that easily turns window ACs into mini splits, by just extending the pipes leading to the coil, ill see if I can find the vid on youtube..

Even a small core should work in your case, but it wouldnt hurt to go a little bigger to get the max effeciency. Also you can hook a couple cheap digi temp controllers up to the fans, with the probe sensors on each end of the core to really dial it in, thats the part I havent put much time into thinking about. An arduino computer chip could be programmed to control it as well, but I might be over thinking that idea and totally not needed..


BTW my custom room build has been ongoing for over 2.5 years now, and I was gonna wait till it was mostly finished to make a post, but maybe I"ll go ahead and make a post here in Palindromes workshop anyway with all the pics I took and start documenting as I finish it off. Building grow rooms and diy equipment is my fav part of the hobby, and the DIY HRV system will be a cool addition hopefully before next winter, and could literally save $100s of dollars compared to how I was running b4

Hey again DropThatSound. March ended up being a hectic time, spring is starting to show its head again.

Looking foreward a tour of your grow set up whenever a tour gets posted lots of ideas to draw from by the sound of it. The diy aspect of growing is by far the best part and builds can (do) always get more and more ambitious haha.

I hadn’t considered condensation from the heat exchanger, shouldn’t be a problem in the shed like it’d be in a full room. Are you ditching the heat exchanger in the flower room? Replacing it with lower airflow and CO2?

The manifold has ended up six cans long, about a meter. May as well make the most of the length available along the back.

Having the full fridge cooling system for dehumidification would be the dream - Iv been fiddling around with a 60w pelter module for dehumidification, especially if there’s flower drying in there. Buts its fiddly and the fridge is already dry enough as is.

Arduino or raspberry pi automation is the end game for this build... That’s a stretch goal tho,,, first off is to get a viable environment.

Update: the solid dried out over the last few weeks. Ended up throwing in some throw away seeds; Swiss cheese from nirvana (they did crap outdoors last summer outdoors) and west cork wonder (local stuff, comes in a 50 pack of seeds haha).

Bigger plants are Swiss cheese


Also was at spannabis for the first time, mad event. Picked up a few seeds there. Too many seeds stocking up...

Hey icmag. Hope all is well.

Had the fridge hooked back up the last little while. Been a while since anything has been grown properly.

I tried to install the heat exchanger, but it was so poorly done I ended up taking it back down.

Other than that the 80mm fans have been swapped for a large 120mm - much better agitation that way, and far less bulky. And there is some side lighting now.

It's so sad that these plants still have to hide away inside fridges in summer time. Ace's Kali china in there now.

And on and on and up and up

omg, it has grown up so good.

Man, you're so good at this. They have grown insanely fast, and they look huge. I'm happy for you. I just wanted to ask you where you got the seeds and what kind of refrigerator you use. I want to try to do the same thing, and I have already saved up all the cans of beer from my friends and myself.

Man, you're so good at this. They have grown insanely fast, and they look huge. I'm happy for you. I just wanted to ask you where you got the seeds and what kind of refrigerator you use. I want to try to do the same thing, and I have already saved up all the cans of beer from my friends and myself. I'm just wondering if the refrigerator from ianboer.com.au. What do you say?" My refrigerator is not very new and I'm afraid that it will not fail.

Nice one!
i wouldn't worry about temps so much. I simply run a heater cable around the pots and have added a temp gauge that now controls the cable heat and as long as the roots are warm enough the rest will be fine!
Best of luck
CC